Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
5.4
4.5
Journals
Plants
Editor’s Choice
share announcement

Editor’s Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

Order results
Result details
Results per page
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
12 pages, 3646 KiB  
Review
β-Ionone: Its Occurrence and Biological Function and Metabolic Engineering
by Antonello Paparella, Liora Shaltiel-Harpaza and Mwafaq Ibdah
Plants 2021, 10(4), 754; https://doi.org/10.3390/plants10040754 - 12 Apr 2021
Cited by 56 | Viewed by 7207
Abstract
β-Ionone is a natural plant volatile compound, and it is the 9,10 and 9′,10′ cleavage product of β-carotene by the carotenoid cleavage dioxygenase. β-Ionone is widely distributed in flowers, fruits, and vegetables. β-Ionone and other apocarotenoids comprise flavors, aromas, pigments, growth regulators, and [...] Read more.
β-Ionone is a natural plant volatile compound, and it is the 9,10 and 9′,10′ cleavage product of β-carotene by the carotenoid cleavage dioxygenase. β-Ionone is widely distributed in flowers, fruits, and vegetables. β-Ionone and other apocarotenoids comprise flavors, aromas, pigments, growth regulators, and defense compounds; serve as ecological cues; have roles as insect attractants or repellants, and have antibacterial and fungicidal properties. In recent years, β-ionone has also received increased attention from the biomedical community for its potential as an anticancer treatment and for other human health benefits. However, β-ionone is typically produced at relatively low levels in plants. Thus, expressing plant biosynthetic pathway genes in microbial hosts and engineering the metabolic pathway/host to increase metabolite production is an appealing alternative. In the present review, we discuss β-ionone occurrence, the biological activities of β-ionone, emphasizing insect attractant/repellant activities, and the current strategies and achievements used to reconstruct enzyme pathways in microorganisms in an effort to to attain higher amounts of the desired β-ionone. Full article
(This article belongs to the Collection Bioactive Compounds in Plants)
►▼ Show Figures

Figure 1

22 pages, 7622 KiB  
Review
Natural Blues: Structure Meets Function in Anthocyanins
by Alan Houghton, Ingo Appelhagen and Cathie Martin
Plants 2021, 10(4), 726; https://doi.org/10.3390/plants10040726 - 8 Apr 2021
Cited by 63 | Viewed by 10801
Abstract
Choices of blue food colourants are extremely limited, with only two options in the USA, synthetic blue no. 1 and no. 2, and a third available in Europe, patent blue V. The food industry is investing heavily in finding naturally derived replacements, with [...] Read more.
Choices of blue food colourants are extremely limited, with only two options in the USA, synthetic blue no. 1 and no. 2, and a third available in Europe, patent blue V. The food industry is investing heavily in finding naturally derived replacements, with limited success to date. Here, we review the complex and multifold mechanisms whereby blue pigmentation by anthocyanins is achieved in nature. Our aim is to explain how structure determines the functionality of anthocyanin pigments, particularly their colour and their stability. Where possible, we describe the impact of progressive decorations on colour and stability, drawn from extensive but diverse physico-chemical studies. We also consider briefly how this understanding could be harnessed to develop blue food colourants on the basis of the understanding of how anthocyanins create blues in nature. Full article
(This article belongs to the Special Issue Plant Colours Omics and Biotechnological Advances)
►▼ Show Figures

Graphical abstract

17 pages, 2171 KiB  
Article
Laurus nobilis, Salvia sclarea and Salvia officinalis Essential Oils and Hydrolates: Evaluation of Liquid and Vapor Phase Chemical Composition and Biological Activities
by Elisa Ovidi, Valentina Laghezza Masci, Marta Zambelli, Antonio Tiezzi, Sara Vitalini and Stefania Garzoli
Plants 2021, 10(4), 707; https://doi.org/10.3390/plants10040707 - 6 Apr 2021
Cited by 36 | Viewed by 4114
Abstract
Laurus nobilis, Salvia officinalis and Salvia sclarea essential oils (EOs) and hydrolates (HYs) were investigated to define their chemical compositions and biological properties. Gas-chromatography/Mass-spectrometry (GC/MS) and Headspace-GC/MS (HS-GC/MS) techniques were used to characterize the liquid and vapor phase chemical composition of EOs [...] Read more.
Laurus nobilis, Salvia officinalis and Salvia sclarea essential oils (EOs) and hydrolates (HYs) were investigated to define their chemical compositions and biological properties. Gas-chromatography/Mass-spectrometry (GC/MS) and Headspace-GC/MS (HS-GC/MS) techniques were used to characterize the liquid and vapor phase chemical composition of EOs and HYs. 1,8-Cineole (42.2%, 33.5%) and α-pinene (16.7%, 39.0%) were the main compounds of L. nobilis EO; 1,8-cineole (30.3%, 48.4%) and camphor (17.1%, 8.7%) were for S. officinalis EO; linalyl acetate (62.6%, 30.1%) and linalool (11.1%, 28.9%) were for S. sclarea EO for the liquid and vapor phase, respectively. Chemical profile of HYs was characterized by 1,8-cineole (65.1%, 61.4%) as a main constituent of L. nobilis and S. officinalis HYs, while linalool (89.5%) was the main constituent of S. sclarea HY. The antioxidant activity of EOs and HYs was carried out by DPPH and ABTS assays and antimicrobial properties were also investigated by microdilution and the disc diffusion method for liquid and vapor phase against five different bacterial strains such as Escherichia coli ATCC 25922, Pseudomonas fluorescens ATCC 13525 and Acinetobacter bohemicus DSM 102855 among Gram-negative and Bacillus cereus ATCC 10876 and Kocuria marina DSM 16420 among Gram-positive. L. nobilis and S. officinalis EOs demonstrated considerable antibacterial activity, while S. sclarea EO proved to be less effective. Agar diffusion method and vapor phase test showed the EOs activity with the biggest halo inhibition diameters against A. bohemicus and B. cereus. A remarkably high antioxidant activity was determined for L. nobilis showing low EC50 values and also for S. sclarea; good EO results were obtained in both of the used assays. S. officinalis EC50 values were slightly higher to which corresponds to a lower antioxidant activity. Concerning the HYs, the EC50 values for L. nobilis, S. officinalis and S. sclarea were remarkably high corresponding to an extremely low antioxidant activity, as also obtained by expressing the values in Trolox equivalent antioxidant capacity (TEAC). Full article
(This article belongs to the Special Issue Chemical Composition and Antimicrobial Activity of Essential Oils)
►▼ Show Figures

Figure 1

14 pages, 2284 KiB  
Article
Chitosan Nanoparticles Loaded with N-Acetyl Cysteine to Mitigate Ozone and Other Possible Oxidative Stresses in Durum Wheat
by Valentina Picchi, Serena Gobbi, Matteo Fattizzo, Mario Zefelippo and Franco Faoro
Plants 2021, 10(4), 691; https://doi.org/10.3390/plants10040691 - 2 Apr 2021
Cited by 30 | Viewed by 2897
Abstract
Modern durum wheat cultivars are more prone to ozone stress because of their high photosynthetic efficiency and leaf gas exchanges that cause a greater pollutant uptake. This, in turn, generates an increased reactive oxygen species (ROS) production that is a challenge to control [...] Read more.
Modern durum wheat cultivars are more prone to ozone stress because of their high photosynthetic efficiency and leaf gas exchanges that cause a greater pollutant uptake. This, in turn, generates an increased reactive oxygen species (ROS) production that is a challenge to control by the antioxidant system of the plant, therefore affecting final yield, with a reduction up to 25%. With the aim of mitigating oxidative stress in wheat, we used chitosan nanoparticles (CHT-NPs) either unloaded or loaded with the antioxidant compound N-acetyl cysteine (NAC), on plants grown either in a greenhouse or in an open field. NAC-loaded NPs were prepared by adding 0.5 mg/mL NAC to the CHT solution before ionotropic gelation with tripolyphosphate (TTP). Greenhouse experiments evidenced that CHT-NPs and CHT-NPs-NAC were able to increase the level of the leaf antioxidant pool, particularly ascorbic acid (AsA) content. However, the results of field trials, while confirming the increase in the AsA level, at least in the first phenological stages, were less conclusive. The presence of NAC did not appear to significantly affect the leaf antioxidant pool, although the grain yield was slightly higher in NAC-treated parcels. Furthermore, both NAC-loaded and -unloaded CHT-NPs partially reduced the symptom severity and increased the weight of 1000 seeds, thus showing a moderate mitigation of ozone injury. Full article
(This article belongs to the Special Issue Responses of Durum Wheat to Abiotic Stress)
►▼ Show Figures

Figure 1

22 pages, 735 KiB  
Review
Plant Biostimulants from Cyanobacteria: An Emerging Strategy to Improve Yields and Sustainability in Agriculture
by Gaia Santini, Natascia Biondi, Liliana Rodolfi and Mario R. Tredici
Plants 2021, 10(4), 643; https://doi.org/10.3390/plants10040643 - 29 Mar 2021
Cited by 54 | Viewed by 6631
Abstract
Cyanobacteria can be considered a promising source for the development of new biostimulants as they are known to produce a variety of biologically active molecules that can positively affect plant growth, nutrient use efficiency, qualitative traits of the final product, and increase plant [...] Read more.
Cyanobacteria can be considered a promising source for the development of new biostimulants as they are known to produce a variety of biologically active molecules that can positively affect plant growth, nutrient use efficiency, qualitative traits of the final product, and increase plant tolerance to abiotic stresses. Moreover, the cultivation of cyanobacteria in controlled and confined systems, along with their metabolic plasticity, provides the possibility to improve and standardize composition and effects on plants of derived biostimulant extracts or hydrolysates, which is one of the most critical aspects in the production of commercial biostimulants. Faced with these opportunities, research on biostimulant properties of cyanobacteria has undergone a significant growth in recent years. However, research in this field is still scarce, especially as regards the number of investigated cyanobacterial species. Future research should focus on reducing the costs of cyanobacterial biomass production and plant treatment and on identifying the molecules that mediate the biostimulant effects in order to optimize their content and stability in the final product. Furthermore, the extension of agronomic trials to a wider number of plant species, different application doses, and environmental conditions would allow the development of tailored microbial biostimulants, thus facilitating the diffusion of these products among farmers. Full article
(This article belongs to the Special Issue Cyanobacteria and Microalgae Biotechnologies)
►▼ Show Figures

Figure 1

28 pages, 1154 KiB  
Review
Metal and Metalloid Toxicity in Plants: An Overview on Molecular Aspects
by Paola I. Angulo-Bejarano, Jonathan Puente-Rivera and Rocío Cruz-Ortega
Plants 2021, 10(4), 635; https://doi.org/10.3390/plants10040635 - 27 Mar 2021
Cited by 145 | Viewed by 10153
Abstract
Worldwide, the effects of metal and metalloid toxicity are increasing, mainly due to anthropogenic causes. Soil contamination ranks among the most important factors, since it affects crop yield, and the metals/metalloids can enter the food chain and undergo biomagnification, having concomitant effects on [...] Read more.
Worldwide, the effects of metal and metalloid toxicity are increasing, mainly due to anthropogenic causes. Soil contamination ranks among the most important factors, since it affects crop yield, and the metals/metalloids can enter the food chain and undergo biomagnification, having concomitant effects on human health and alterations to the environment. Plants have developed complex mechanisms to overcome these biotic and abiotic stresses during evolution. Metals and metalloids exert several effects on plants generated by elements such as Zn, Cu, Al, Pb, Cd, and As, among others. The main strategies involve hyperaccumulation, tolerance, exclusion, and chelation with organic molecules. Recent studies in the omics era have increased knowledge on the plant genome and transcriptome plasticity to defend against these stimuli. The aim of the present review is to summarize relevant findings on the mechanisms by which plants take up, accumulate, transport, tolerate, and respond to this metal/metalloid stress. We also address some of the potential applications of biotechnology to improve plant tolerance or increase accumulation. Full article
(This article belongs to the Special Issue Heavy Metal Stress in Plants)
►▼ Show Figures

Figure 1

26 pages, 1178 KiB  
Review
Priming Strategies for Benefiting Plant Performance under Toxic Trace Metal Exposure
by Alina Wiszniewska
Plants 2021, 10(4), 623; https://doi.org/10.3390/plants10040623 - 25 Mar 2021
Cited by 29 | Viewed by 4541
Abstract
Combating environmental stress related to the presence of toxic elements is one of the most important challenges in plant production. The majority of plant species suffer from developmental abnormalities caused by an exposure to toxic concentrations of metals and metalloids, mainly Al, As, [...] Read more.
Combating environmental stress related to the presence of toxic elements is one of the most important challenges in plant production. The majority of plant species suffer from developmental abnormalities caused by an exposure to toxic concentrations of metals and metalloids, mainly Al, As, Cd, Cu, Hg, Ni, Pb, and Zn. However, defense mechanisms are activated with diverse intensity and efficiency. Enhancement of defense potential can be achieved though exogenously applied treatments, resulting in a higher capability of surviving and developing under stress and become, at least temporarily, tolerant to stress factors. In this review, I present several already recognized as well as novel methods of the priming process called priming, resulting in the so-called “primed state” of the plant organism. Primed plants have a higher capability of surviving and developing under stress, and become, at least temporarily, tolerant to stress factors. In this review, several already recognized as well as novel methods of priming plants towards tolerance to metallic stress are discussed, with attention paid to similarities in priming mechanisms activated by the most versatile priming agents. This knowledge could contribute to the development of priming mixtures to counteract negative effects of multi-metallic and multi-abiotic stresses. Presentation of mechanisms is complemented with information on the genes regulated by priming towards metallic stress tolerance. Novel compounds and techniques that can be exploited in priming experiments are also summarized. Full article
(This article belongs to the Special Issue Heavy Metal Stress in Plants)
►▼ Show Figures

Figure 1

19 pages, 4206 KiB  
Article
Impact of Germination on the Microstructural and Physicochemical Properties of Different Legume Types
by Denisa Atudorei, Silviu-Gabriel Stroe and Georgiana Gabriela Codină
Plants 2021, 10(3), 592; https://doi.org/10.3390/plants10030592 - 22 Mar 2021
Cited by 48 | Viewed by 6080
Abstract
The microstructural and physicochemical compositions of bean (Phaseolus vulgaris), lentil (Lens culinaris Merr.), soybean (Glycine max L.), chickpea (Cicer aretinium L.) and lupine (Lupinus albus) were investigated over 2 and 4 days of germination. Different [...] Read more.
The microstructural and physicochemical compositions of bean (Phaseolus vulgaris), lentil (Lens culinaris Merr.), soybean (Glycine max L.), chickpea (Cicer aretinium L.) and lupine (Lupinus albus) were investigated over 2 and 4 days of germination. Different changes were noticed during microscopic observations (Stereo Microscope, SEM) of the legume seeds subjected to germination, mostly related to the breakages of the seed structure. The germination caused the increase in protein content for bean, lentil, and chickpea and of ash content for lentil, soybean and chickpea. Germination increased the availability of sodium, magnesium, iron, zinc and also the acidity for all legume types. The content of fat decreased for lentil, chickpea, and lupine, whereas the content of carbohydrates and pH decreased for all legume types during the four-day germination period. Fourier transform infrared spectroscopic (FT-IR) spectra show that the compositions of germinated seeds were different from the control and varied depending on the type of legume. The multivariate analysis of the data shows close associations between chickpea, lentil, and bean and between lupine and soybean samples during the germination process. Significant negative correlations were obtained between carbohydrate contents and protein, fat and ash at the 0.01 level. Full article
(This article belongs to the Special Issue Quality Evaluation of Plant-Derived Foods)
►▼ Show Figures

Figure 1

20 pages, 3168 KiB  
Article
Ecological and Plant Community Implication on Essential Oils Composition in Useful Wild Officinal Species: A Pilot Case Study in Apulia (Italy)
by Enrico V. Perrino, Francesca Valerio, Ahmed Gannouchi, Antonio Trani and Giuseppe Mezzapesa
Plants 2021, 10(3), 574; https://doi.org/10.3390/plants10030574 - 18 Mar 2021
Cited by 54 | Viewed by 3978
Abstract
The study focused on the effects of ecology (plant communities and topographical data) on composition of essential oils (EOs) of some officinal wild plant species (Lamiales): Clinopodium suaveolens, Salvia fruticosa subsp. thomasii, Satureja montana subsp. montana, and Thymbra capitata, in different [...] Read more.
The study focused on the effects of ecology (plant communities and topographical data) on composition of essential oils (EOs) of some officinal wild plant species (Lamiales): Clinopodium suaveolens, Salvia fruticosa subsp. thomasii, Satureja montana subsp. montana, and Thymbra capitata, in different environments of Apulia (Italy). C. suaveolens and S. fruticosa subsp. thomasii are rare species of conservation interest, while S. montana subsp. montana and T. capitata, have a wide distribution and are used in traditional medicine or as spices. Results showed that the ecological context (phytosociological and ecological features) may influence the composition of EOs of the studied species. High differences in the compound composition have been found in S. montana subsp. montana, whereas minor effects were observed in C. suaveolens, S. fruticosa subsp. thomasii, and T. capitata accessions. The understanding of such aspects is necessary for providing optimal conditions to produce EOs rich in compounds known for their biological activities. The results are of great interest also for EOs producers and at the same time to improve our knowledge and valorize wild officinal plants. Full article
(This article belongs to the Section Plant Ecology)
►▼ Show Figures

Figure 1

17 pages, 1193 KiB  
Review
Wild Plants Used as Herbs and Spices in Italy: An Ethnobotanical Review
by Riccardo Motti
Plants 2021, 10(3), 563; https://doi.org/10.3390/plants10030563 - 16 Mar 2021
Cited by 32 | Viewed by 4636
Abstract
Wild edible plants are an essential component of people’s diets in the Mediterranean basin. In Italy, ethnobotanical surveys have received increasing attention in the past two centuries, with some of these studies focusing on wild edible plants. In this regard, the literature in [...] Read more.
Wild edible plants are an essential component of people’s diets in the Mediterranean basin. In Italy, ethnobotanical surveys have received increasing attention in the past two centuries, with some of these studies focusing on wild edible plants. In this regard, the literature in Italy lacks the coverage of some major issues focusing on plants used as herbs and spices. I searched national journals for articles on the use of wild food plants in Italy, published from 1963 to 2020. Aims of the present review were to document plant lore regarding wild herbs and spices in Italy, identify the wild plants most frequently used as spices, analyze the distribution of wild herbs and spices used at a national scale, and finally, to describe the most common phytochemical compounds present in wild plant species. Based on the 34 studies reviewed, I documented 78 wild taxa as being used in Italy as herbs or spices. The studies I included in this systematic review demonstrate that wild species used as herbs and spices enrich Italian folk cuisine and can represent an important resource for profitable, integrated local small-scale activities. Full article
(This article belongs to the Collection Botany of Food Plants)
►▼ Show Figures

Figure 1

17 pages, 2987 KiB  
Article
Comparative Study of Drought Stress Effects on Traditional and Modern Apple Cultivars
by Ines Mihaljević, Marija Viljevac Vuletić, Domagoj Šimić, Vesna Tomaš, Daniela Horvat, Marko Josipović, Zvonimir Zdunić, Krunoslav Dugalić and Dominik Vuković
Plants 2021, 10(3), 561; https://doi.org/10.3390/plants10030561 - 16 Mar 2021
Cited by 38 | Viewed by 4520
Abstract
Genotype-dependent responses of apples to drought stress were evaluated between commercial and traditional apple cultivars. The results indicate different mechanisms of tolerance to investigated drought stress conditions. Chlorophyll fluorescence induction (OJIP) parameters, chlorophyll and carotenoid content, malondialdehyde (MDA), hydrogen peroxide (H2O [...] Read more.
Genotype-dependent responses of apples to drought stress were evaluated between commercial and traditional apple cultivars. The results indicate different mechanisms of tolerance to investigated drought stress conditions. Chlorophyll fluorescence induction (OJIP) parameters, chlorophyll and carotenoid content, malondialdehyde (MDA), hydrogen peroxide (H2O2), proline, phenols and leaf water content (WC) were measured. The traditional cultivar “Crvenka” confirmed the best tolerance to a drought stress condition, presenting higher photosynthetic efficiency, higher leaf water content, higher levels of chlorophyll content and lower lipid peroxidation with greater membrane stability. The commercial cultivar “Golden Delicious Reinders” showed decreased water content in leaves, increased lipid peroxidation levels and photoinhibition. Considering all results, the commercial cultivar “Golden Delicious Reinders” was adversely affected by drought, while traditional cultivars exhibited better tolerance to drought stress. Full article
(This article belongs to the Special Issue Physiology and Molecular Biology of Fruit Trees and Vines)
►▼ Show Figures

Figure 1

18 pages, 18328 KiB  
Article
Phenolic Compounds and Biological Activity of Selected Mentha Species
by Sanja Ćavar Zeljković, Jana Šišková, Karolína Komzáková, Nuria De Diego, Katarína Kaffková and Petr Tarkowski
Plants 2021, 10(3), 550; https://doi.org/10.3390/plants10030550 - 15 Mar 2021
Cited by 59 | Viewed by 6283
Abstract
Mentha species are widely used as food, medicine, spices, and flavoring agents. Thus, chemical composition is an important parameter for assessing the quality of mints. In general, the contents of menthol, menthone, eucalyptol, and limonene comprise one of the major parameters for assessing [...] Read more.
Mentha species are widely used as food, medicine, spices, and flavoring agents. Thus, chemical composition is an important parameter for assessing the quality of mints. In general, the contents of menthol, menthone, eucalyptol, and limonene comprise one of the major parameters for assessing the quality of commercially important mints. Building further on the phytochemical characterization of the quality of Mentha species, this work was focused on the composition of phenolic compounds in methanolic extracts. Thirteen Mentha species were grown under the same environmental conditions, and their methanolic extracts were subjected to the LC–MS/MS (liquid chromatography–tandem mass spectrometry) profiling of phenolics and the testing their biological activities, i.e., antioxidant and tyrosinase inhibition activities, which are important features for the cosmetic industry. The total phenolic content (TPC) ranged from 14.81 ± 1.09 mg GAE (gallic acid equivalents)/g for Mentha cervina to 58.93. ± 8.39 mg GAE/g for Mentha suaveolens. The antioxidant activity of examined Mentha related with the content of the phenolic compounds and ranged from 22.79 ± 1.85 to 106.04 ± 3.26 mg TE (Trolox equivalents)/g for M. cervina and Mentha x villosa, respectively. Additionally, Mentha pulegium (123.89 ± 5.64 mg KAE (kojic acid equivalents)/g) and Mentha x piperita (102.82 ± 15.16 mg KAE/g) showed a strong inhibition of the enzyme tyrosinase, which is related to skin hyperpigmentation. The most abundant compound in all samples was rosmarinic acid, ranging from 1363.38 ± 8323 to 2557.08 ± 64.21 μg/g. In general, the levels of phenolic acids in all examined mint extracts did not significantly differ. On the contrary, the levels of flavonoids varied within the species, especially in the case of hesperidin (from 0.73 ± 0.02 to 109. 39 ± 2.01 μg/g), luteolin (from 1.84 ± 0.11 to 31.03 ± 0.16 μg/g), and kaempferol (from 1.30 ± 0.17 to 33.68 ± 0.81 μg/g). Overall results indicated that all examined mints possess significant amounts of phenolic compounds that are responsible for antioxidant activity and, to some extent, for tyrosinase inhibition activity. Phenolics also proved to be adequate compounds, together with terpenoids, for the characterization of Mentha sp. Additionally, citrus-scented Mentha x villosa could be selected as a good candidate for the food and pharmaceutical industry, especially due its chemical composition and easy cultivation, even in winter continental conditions. Full article
(This article belongs to the Special Issue Plant Polyphenols—from Plants to Human Health)
►▼ Show Figures

Figure 1

15 pages, 559 KiB  
Article
Sustainable Processing of Floral Bio-Residues of Saffron (Crocus sativus L.) for Valuable Biorefinery Products
by Stefania Stelluti, Matteo Caser, Sonia Demasi and Valentina Scariot
Plants 2021, 10(3), 523; https://doi.org/10.3390/plants10030523 - 11 Mar 2021
Cited by 35 | Viewed by 3048
Abstract
Tepals constitute the most abundant bio-residues of saffron (Crocus sativus L.). As they are a natural source of polyphenols with antioxidant properties, they could be processed to generate valuable biorefinery products for applications in the pharmaceutical, cosmetic, and food industries, becoming a [...] Read more.
Tepals constitute the most abundant bio-residues of saffron (Crocus sativus L.). As they are a natural source of polyphenols with antioxidant properties, they could be processed to generate valuable biorefinery products for applications in the pharmaceutical, cosmetic, and food industries, becoming a new source of income while reducing bio-waste. Proper storage of by-products is important in biorefining and dehydration is widely used in the herb sector, especially for highly perishable harvested flowers. This study aimed to deepen the phytochemical composition of dried saffron tepals and to investigate whether this was influenced by the extraction technique. In particular, the conventional maceration was compared with the Ultrasound Assisted Extraction (UAE), using different solvents (water and three methanol concentrations, i.e., 20%, 50%, and 80%). Compared to the spice, the dried saffron tepals showed a lower content of total phenolics (average value 1127.94 ± 32.34 mg GAE 100 g−1 DW) and anthocyanins (up to 413.30 ± 137.16 mg G3G 100 g−1 DW), but a higher antioxidant activity, which was measured through the FRAP, ABTS, and DPPH assays. The HPLC-DAD analysis detected some phenolic compounds (i.e., ferulic acid, isoquercitrin, and quercitrin) not previously found in fresh saffron tepals. Vitamin C, already discovered in the spice, was interestingly detected also in dried tepals. Regarding the extraction technique, in most cases, UAE with safer solvents (i.e., water or low percentage of methanol) showed results of phenolic compounds and vitamin C similar to maceration, allowing an improvement in extractions by halving the time. Thus, this study demonstrated that saffron tepals can be dried maintaining their quality and that green extractions can be adopted to obtain high yields of valuable antioxidant phytochemicals, meeting the requirement for a sustainable biorefining. Full article
(This article belongs to the Special Issue Isolation and Analysis of Characteristic Compounds from Herbal and Plant Extracts)
►▼ Show Figures

Figure 1

14 pages, 9268 KiB  
Article
Hormetic Responses of Photosystem II in Tomato to Botrytis cinerea
by Maria-Lavrentia Stamelou, Ilektra Sperdouli, Ioanna Pyrri, Ioannis-Dimosthenis S. Adamakis and Michael Moustakas
Plants 2021, 10(3), 521; https://doi.org/10.3390/plants10030521 - 10 Mar 2021
Cited by 29 | Viewed by 3046
Abstract
Botrytis cinerea, a fungal pathogen that causes gray mold, is damaging more than 200 plant species, and especially tomato. Photosystem II (PSII) responses in tomato (Solanum lycopersicum L.) leaves to Botrytis cinerea spore suspension application were evaluated by chlorophyll fluorescence imaging [...] Read more.
Botrytis cinerea, a fungal pathogen that causes gray mold, is damaging more than 200 plant species, and especially tomato. Photosystem II (PSII) responses in tomato (Solanum lycopersicum L.) leaves to Botrytis cinerea spore suspension application were evaluated by chlorophyll fluorescence imaging analysis. Hydrogen peroxide (H2O2) that was detected 30 min after Botrytis application with an increasing trend up to 240 min, is possibly convening tolerance against B. cinerea at short-time exposure, but when increasing at relative longer exposure, is becoming a damaging molecule. In accordance, an enhanced photosystem II (PSII) functionality was observed 30 min after application of B. cinerea, with a higher fraction of absorbed light energy to be directed to photochemistry (ΦPSΙΙ). The concomitant increase in the photoprotective mechanism of non-photochemical quenching of photosynthesis (NPQ) resulted in a significant decrease in the dissipated non-regulated energy (ΦNO), indicating a possible decreased singlet oxygen (1O2) formation, thus specifying a modified reactive oxygen species (ROS) homeostasis. Therefore, 30 min after application of Botrytis spore suspension, before any visual symptoms appeared, defense response mechanisms were triggered, with PSII photochemistry to be adjusted by NPQ in a such way that PSII functionality to be enhanced, but being fully inhibited at the application spot and the adjacent area, after longer exposure (240 min). Hence, the response of tomato PSII to B. cinerea, indicates a hormetic temporal response in terms of “stress defense response” and “toxicity”, expanding the features of hormesis to biotic factors also. The enhanced PSII functionality 30 min after Botrytis application can possible be related with the need of an increased sugar production that is associated with a stronger plant defense potential through the induction of defense genes. Full article
(This article belongs to the Special Issue Photosynthetic Responses to Biotic and Abiotic Stress)
►▼ Show Figures

Figure 1

18 pages, 1763 KiB  
Article
Comparative Study of Chemical Composition and Antioxidant Activity of Essential Oils and Crude Extracts of Four Characteristic Zingiberaceae Herbs
by Milena Ivanović, Kaja Makoter and Maša Islamčević Razboršek
Plants 2021, 10(3), 501; https://doi.org/10.3390/plants10030501 - 8 Mar 2021
Cited by 38 | Viewed by 5386
Abstract
The ginger family (Zingiberaceae) includes plants that are known worldwide to have a distinctive smell and taste, which are often used as spices in the kitchen, but also in various industries (pharmaceutical, medical, and cosmetic) due to their proven biological activity. [...] Read more.
The ginger family (Zingiberaceae) includes plants that are known worldwide to have a distinctive smell and taste, which are often used as spices in the kitchen, but also in various industries (pharmaceutical, medical, and cosmetic) due to their proven biological activity. The aim of this study was to investigate and compare the chemical composition and antioxidant activity (AA) of essential oils (EOs) of four characteristic ginger species: Elettaria cardamomum L. Maton (cardamom), Curcuma Longa L. (turmeric), Zingiber Officinale Roscoe (ginger), and Alpinia Officinarum Hance (galangal). Furthermore, the total phenolic content (TPC) and AA of crude extracts obtained after using ultrasound-assisted extraction (UAE) and different extraction solvents (80% ethanol, 80% methanol and water) were evaluated. A total of 87 different chemical components were determined by GC-MS/MS in the EOs obtained after hydrodistillation, 14 of which were identified in varying amounts in all EOs. The major compounds found in cardamom, turmeric, ginger, and galangal were α-terpinyl acetate (40.70%), β-turmerone (25.77%), α-zingiberene (22.69%) and 1,8-cineol (42.71%), respectively. In general, 80% ethanol was found to be the most effective extracting solvent for the bioactivities of the investigated species from the Zingiberaceae family. Among the crude extracts, ethanolic extract of galangal showed the highest TPC value (63.01 ± 1.06 mg GA g−1 DW), while the lowest TPC content was found in cardamom water extract (1.04 ± 0.29 mg GA g−1 DW). The AA evaluated by two different assays (ferric-reducing antioxidant power-FRAP and the scavenging activity of the cationic ABTS radical) proved that galangal rhizome is the plant with the highest antioxidant potential. In addition, no statistical difference was found between the AA of turmeric and ginger extracts, while cardamom rhizome was again inferior. In contrast to the crude extracts, the EOs resulted in significantly lower ABTS and FRAP values, with turmeric EO showing the highest AA. Full article
(This article belongs to the Special Issue Plant Analytical Chemistry)
►▼ Show Figures

Figure 1

31 pages, 3200 KiB  
Article
Genetic Diversity and Pathogenicity of Botryosphaeriaceae Species Associated with Symptomatic Citrus Plants in Europe
by Jadson Diogo Pereira Bezerra, Pedro Wilhelm Crous, Dalia Aiello, Maria Lodovica Gullino, Giancarlo Polizzi and Vladimiro Guarnaccia
Plants 2021, 10(3), 492; https://doi.org/10.3390/plants10030492 - 5 Mar 2021
Cited by 34 | Viewed by 3570
Abstract
This study represents the first survey studying the occurrence, genetic diversity, and pathogenicity of Botryosphaeriaceae species associated with symptomatic citrus species in citrus-production areas in five European countries. Based on morphological features and phylogenetic analyses of internal transcribed spacer (ITS) of nuclear ribosomal [...] Read more.
This study represents the first survey studying the occurrence, genetic diversity, and pathogenicity of Botryosphaeriaceae species associated with symptomatic citrus species in citrus-production areas in five European countries. Based on morphological features and phylogenetic analyses of internal transcribed spacer (ITS) of nuclear ribosomal DNA (nrDNA), translation elongation factor 1-alpha (TEF1) and β-tubulin (TUB2) genes, nine species were identified as belonging to the genera Diplodia, Dothiorella, Lasiodiplodia, and Neofusicoccum. Isolates of Neofusicoccum parvum and Diplodia pseudoseriata were the most frequently detected, while Dothiorella viticola had the widest distribution, occurring in four of the five countries sampled. Representative isolates of the nine Botryosphaeriaceae species used in the pathogenicity tests caused similar symptoms to those observed in nature. Isolates assayed were all re-isolated, thereby fulfilling Koch’s postulates. Isolates of Diplodia pseudoseriata and Diplodia olivarum are recorded for the first time on citrus and all species found in our study, except N. parvum, are reported for the first time on citrus in Europe. Full article
(This article belongs to the Special Issue Citrus Fungal and Oomycete Diseases)
►▼ Show Figures

Figure 1

13 pages, 1264 KiB  
Article
DNA Modification Patterns within the Transposable Elements of the Fig (Ficus carica L.) Genome
by Gabriele Usai, Alberto Vangelisti, Samuel Simoni, Tommaso Giordani, Lucia Natali, Andrea Cavallini and Flavia Mascagni
Plants 2021, 10(3), 451; https://doi.org/10.3390/plants10030451 - 27 Feb 2021
Cited by 16 | Viewed by 2686
Abstract
Transposable element activity can be harmful to the host’s genome integrity, but it can also provide selective advantages. One strategy to cope with transposons is epigenetic control through DNA base modifications. We report the non-canonic DNA modification dynamics of fig (Ficus carica [...] Read more.
Transposable element activity can be harmful to the host’s genome integrity, but it can also provide selective advantages. One strategy to cope with transposons is epigenetic control through DNA base modifications. We report the non-canonic DNA modification dynamics of fig (Ficus carica L.) by exploiting high-quality genome reference and related N4-methylcytosine (4mC) and N6-methyladenine (6mA) data. Overall, 1.49% of transposon nucleotides showed either 4mC or 6mA modifications: the 4mC/6mA ratio was similar in Class I and Class II transposons, with a prevalence of 4mC, which is comparable to coding genes. Different percentages of 4mC or 6mA were observed among LTR-retrotransposon lineages and sub-lineages. Furthermore, both the Copia and Gypsy retroelements showed higher modification rates in the LTR and coding regions compared with their neighbour regions. Finally, the unconventional methylation of retrotransposons is unrelated to the number of close genes, suggesting that the 4mC and 6mA frequency in LTR-retrotransposons should not be related to transcriptional repression in the adjacency of the element. In conclusion, this study highlighted unconventional DNA modification patterns in fig transposable elements. Further investigations will focus on functional implications, in regards to how modified retroelements affect the expression of neighbouring genes, and whether these epigenetic markers can spread from repeats to genes, shaping the plant phenotype. Full article
(This article belongs to the Special Issue DNA Methylation in Plants)
►▼ Show Figures

Figure 1

12 pages, 717 KiB  
Review
Plant Recovery after Metal Stress—A Review
by Jagna Chmielowska-Bąk and Joanna Deckert
Plants 2021, 10(3), 450; https://doi.org/10.3390/plants10030450 - 27 Feb 2021
Cited by 22 | Viewed by 4707
Abstract
Contamination of the environment with metals, their adverse impact on plant performance and transmission to the human food chain through crops and vegetables are important concerns worldwide. Although the literature on metal contamination, toxicity and plant response to this stress factor is quite [...] Read more.
Contamination of the environment with metals, their adverse impact on plant performance and transmission to the human food chain through crops and vegetables are important concerns worldwide. Although the literature on metal contamination, toxicity and plant response to this stress factor is quite abundant, there are very limited reports on the phenomenon of plant recovery after metal stress. The present article reviews available literature on the recovery process examined in various plant species, in response to several metals (Al, Cd, Cu, Ni, Pb, Zn), applied at different concentrations and treatment duration. The reviewed studies have been carried out in laboratory conditions. However, it should be highlighted that although metal stress is not as transient as most of other stress factors (e.g., drought, heat, chilling), metal concentration in the soil may still decrease due to, e.g., leaching to lower soil layers or uptake by organisms. Thus, in natural conditions, plants may be subjected to post-metal-stress conditions. The review also discusses the mechanism behind efficient recovery and the impact of post metal stress on future plant performance—possible acquisition of stress memory, adaptation to unfavorable conditions and cross-tolerance towards other stress factors. Full article
(This article belongs to the Special Issue Physiological and Molecular Mechanisms of Plant Response to Metal Stress)
►▼ Show Figures

Figure 1

31 pages, 989 KiB  
Perspective
Potassium Control of Plant Functions: Ecological and Agricultural Implications
by Jordi Sardans and Josep Peñuelas
Plants 2021, 10(2), 419; https://doi.org/10.3390/plants10020419 - 23 Feb 2021
Cited by 141 | Viewed by 9923
Abstract
Potassium, mostly as a cation (K+), together with calcium (Ca2+) are the most abundant inorganic chemicals in plant cellular media, but they are rarely discussed. K+ is not a component of molecular or macromolecular plant structures, thus it [...] Read more.
Potassium, mostly as a cation (K+), together with calcium (Ca2+) are the most abundant inorganic chemicals in plant cellular media, but they are rarely discussed. K+ is not a component of molecular or macromolecular plant structures, thus it is more difficult to link it to concrete metabolic pathways than nitrogen or phosphorus. Over the last two decades, many studies have reported on the role of K+ in several physiological functions, including controlling cellular growth and wood formation, xylem–phloem water content and movement, nutrient and metabolite transport, and stress responses. In this paper, we present an overview of contemporary findings associating K+ with various plant functions, emphasizing plant-mediated responses to environmental abiotic and biotic shifts and stresses by controlling transmembrane potentials and water, nutrient, and metabolite transport. These essential roles of K+ account for its high concentrations in the most active plant organs, such as leaves, and are consistent with the increasing number of ecological and agricultural studies that report K+ as a key element in the function and structure of terrestrial ecosystems, crop production, and global food security. We synthesized these roles from an integrated perspective, considering the metabolic and physiological functions of individual plants and their complex roles in terrestrial ecosystem functions and food security within the current context of ongoing global change. Thus, we provide a bridge between studies of K+ at the plant and ecological levels to ultimately claim that K+ should be considered at least at a level similar to N and P in terrestrial ecological studies. Full article
(This article belongs to the Section Plant Ecology)
►▼ Show Figures

Figure 1

13 pages, 699 KiB  
Review
Recapitulation of the Function and Role of ROS Generated in Response to Heat Stress in Plants
by Emily Medina, Su-Hwa Kim, Miriam Yun and Won-Gyu Choi
Plants 2021, 10(2), 371; https://doi.org/10.3390/plants10020371 - 15 Feb 2021
Cited by 73 | Viewed by 8691
Abstract
In natural ecosystems, plants are constantly exposed to changes in their surroundings as they grow, caused by a lifestyle that requires them to live where their seeds fall. Thus, plants strive to adapt and respond to changes in their exposed environment that change [...] Read more.
In natural ecosystems, plants are constantly exposed to changes in their surroundings as they grow, caused by a lifestyle that requires them to live where their seeds fall. Thus, plants strive to adapt and respond to changes in their exposed environment that change every moment. Heat stress that naturally occurs when plants grow in the summer or a tropical area adversely affects plants’ growth and poses a risk to plant development. When plants are subjected to heat stress, they recognize heat stress and respond using highly complex intracellular signaling systems such as reactive oxygen species (ROS). ROS was previously considered a byproduct that impairs plant growth. However, in recent studies, ROS gained attention for its function as a signaling molecule when plants respond to environmental stresses such as heat stress. In particular, ROS, produced in response to heat stress in various plant cell compartments such as mitochondria and chloroplasts, plays a crucial role as a signaling molecule that promotes plant growth and triggers subsequent downstream reactions. Therefore, this review aims to address the latest research trends and understandings, focusing on the function and role of ROS in responding and adapting plants to heat stress. Full article
(This article belongs to the Special Issue Specificity of ROS and Redox Regulatory Systems)
►▼ Show Figures

Figure 1

12 pages, 721 KiB  
Review
Downstream Signalling from Molecular Hydrogen
by John T. Hancock and Grace Russell
Plants 2021, 10(2), 367; https://doi.org/10.3390/plants10020367 - 14 Feb 2021
Cited by 17 | Viewed by 3651
Abstract
Molecular hydrogen (H2) is now considered part of the suite of small molecules that can control cellular activity. As such, H2 has been suggested to be used in the therapy of diseases in humans and in plant science to enhance [...] Read more.
Molecular hydrogen (H2) is now considered part of the suite of small molecules that can control cellular activity. As such, H2 has been suggested to be used in the therapy of diseases in humans and in plant science to enhance the growth and productivity of plants. Treatments of plants may involve the creation of hydrogen-rich water (HRW), which can then be applied to the foliage or roots systems of the plants. However, the molecular action of H2 remains elusive. It has been suggested that the presence of H2 may act as an antioxidant or on the antioxidant capacity of cells, perhaps through the scavenging of hydroxyl radicals. H2 may act through influencing heme oxygenase activity or through the interaction with reactive nitrogen species. However, controversy exists around all the mechanisms suggested. Here, the downstream mechanisms in which H2 may be involved are critically reviewed, with a particular emphasis on the H2 mitigation of stress responses. Hopefully, this review will provide insight that may inform future research in this area. Full article
(This article belongs to the Special Issue Production and Role of Molecular Hydrogen in Plants)
►▼ Show Figures

Graphical abstract

23 pages, 2206 KiB  
Review
A Beginner’s Guide to Osmoprotection by Biostimulants
by David Jiménez-Arias, Francisco J. García-Machado, Sarai Morales-Sierra, Ana L. García-García, Antonio J. Herrera, Francisco Valdés, Juan C. Luis and Andrés A. Borges
Plants 2021, 10(2), 363; https://doi.org/10.3390/plants10020363 - 13 Feb 2021
Cited by 21 | Viewed by 5739
Abstract
Water is indispensable for the life of any organism on Earth. Consequently, osmotic stress due to salinity and drought is the greatest threat to crop productivity. Ongoing climate change includes rising temperatures and less precipitation over large areas of the planet. This is [...] Read more.
Water is indispensable for the life of any organism on Earth. Consequently, osmotic stress due to salinity and drought is the greatest threat to crop productivity. Ongoing climate change includes rising temperatures and less precipitation over large areas of the planet. This is leading to increased vulnerability to the drought conditions that habitually threaten food security in many countries. Such a scenario poses a daunting challenge for scientists: the search for innovative solutions to save water and cultivate under water deficit. A search for formulations including biostimulants capable of improving tolerance to this stress is a promising specific approach. This review updates the most recent state of the art in the field. Full article
(This article belongs to the Special Issue Chemical Activators of the Natural Defences of the Plant)
►▼ Show Figures

Graphical abstract

14 pages, 1987 KiB  
Article
Foliar Application of Different Vegetal-Derived Protein Hydrolysates Distinctively Modulates Tomato Root Development and Metabolism
by Angela Valentina Ceccarelli, Begoña Miras-Moreno, Valentina Buffagni, Biancamaria Senizza, Youry Pii, Mariateresa Cardarelli, Youssef Rouphael, Giuseppe Colla and Luigi Lucini
Plants 2021, 10(2), 326; https://doi.org/10.3390/plants10020326 - 8 Feb 2021
Cited by 43 | Viewed by 4559
Abstract
Despite the scientific evidence supporting their biostimulant activity, the molecular mechanism(s) underlying the activity of protein hydrolysates (PHs) and the specificity among different products are still poorly explored. This work tested five different protein hydrolysates, produced from different plant sources using the same [...] Read more.
Despite the scientific evidence supporting their biostimulant activity, the molecular mechanism(s) underlying the activity of protein hydrolysates (PHs) and the specificity among different products are still poorly explored. This work tested five different protein hydrolysates, produced from different plant sources using the same enzymatic approach, for their ability to promote rooting in tomato cuttings following quick dipping. Provided that all the different PHs increased root length (45–93%) and some of them increased root number (37–56%), untargeted metabolomics followed by multivariate statistics and pathway analysis were used to unravel the molecular processes at the basis of the biostimulant activity. Distinct metabolomic signatures could be found in roots following the PHs treatments. In general, PHs shaped the phytohormone profile, modulating the complex interaction between cytokinins and auxins, an interplay playing a pivotal role in root development, and triggered a down accumulation of brassinosteroids. Concerning secondary metabolism, PHs induced the accumulation of aliphatic glucosinolates, alkaloids, and phenylpropanoids, potentially eliciting crop resilience to stress conditions. Here, we confirm that PHs may have a hormone-like activity, and that their application can modulate plant growth, likely interfering with signaling processes. Noteworthy, the heterogenicity of the botanical origin supported the distinctive and peculiar metabolomic responses we observed across the products tested. While supporting their biostimulant activity, these findings suggest that a generalized crop response to PHs cannot be defined and that specific effects are rather to be investigated. Full article
(This article belongs to the Special Issue Biostimulants as Growth Promoting and Stress Protecting Compounds)
►▼ Show Figures

Figure 1

33 pages, 4287 KiB  
Review
Silicon Cycling in Soils Revisited
by Jörg Schaller, Daniel Puppe, Danuta Kaczorek, Ruth Ellerbrock and Michael Sommer
Plants 2021, 10(2), 295; https://doi.org/10.3390/plants10020295 - 4 Feb 2021
Cited by 119 | Viewed by 7665
Abstract
Silicon (Si) speciation and availability in soils is highly important for ecosystem functioning, because Si is a beneficial element for plant growth. Si chemistry is highly complex compared to other elements in soils, because Si reaction rates are relatively slow and dependent on [...] Read more.
Silicon (Si) speciation and availability in soils is highly important for ecosystem functioning, because Si is a beneficial element for plant growth. Si chemistry is highly complex compared to other elements in soils, because Si reaction rates are relatively slow and dependent on Si species. Consequently, we review the occurrence of different Si species in soil solution and their changes by polymerization, depolymerization, and condensation in relation to important soil processes. We show that an argumentation based on thermodynamic endmembers of Si dependent processes, as currently done, is often difficult, because some reactions such as mineral crystallization require months to years (sometimes even centuries or millennia). Furthermore, we give an overview of Si reactions in soil solution and the predominance of certain solid compounds, which is a neglected but important parameter controlling the availability, reactivity, and function of Si in soils. We further discuss the drivers of soil Si cycling and how humans interfere with these processes. The soil Si cycle is of major importance for ecosystem functioning; therefore, a deeper understanding of drivers of Si cycling (e.g., predominant speciation), human disturbances and the implication for important soil properties (water storage, nutrient availability, and micro aggregate stability) is of fundamental relevance. Full article
(This article belongs to the Special Issue Silicon in the Soil-Plant Continuum)
►▼ Show Figures

Figure 1

17 pages, 4048 KiB  
Article
Can Foliar Pulverization with CaCl2 and Ca(NO3)2 Trigger Ca Enrichment in Solanum tuberosum L. Tubers?
by Ana Rita F. Coelho, Fernando C. Lidon, Cláudia Campos Pessoa, Ana Coelho Marques, Inês Carmo Luís, João Caleiro, Manuela Simões, José Kullberg, Paulo Legoinha, Maria Brito, Mauro Guerra, Roberta G. Leitão, Carlos Galhano, Paula Scotti-Campos, José N. Semedo, Maria Manuela Silva, Isabel P. Pais, Maria J. Silva, Ana P. Rodrigues, Maria F. Pessoa, José C. Ramalho and Fernando H. Reboredoadd Show full author list remove Hide full author list
Plants 2021, 10(2), 245; https://doi.org/10.3390/plants10020245 - 27 Jan 2021
Cited by 23 | Viewed by 2791
Abstract
This study aimed to assess the efficiency of Ca enrichment in tubers of three genotypes of Solanum tuberosum L., through foliar spraying with CaCl2 and Ca(NO3)2 solutions. In this context, soil heterogeneity of three potato-growing fields, as well as [...] Read more.
This study aimed to assess the efficiency of Ca enrichment in tubers of three genotypes of Solanum tuberosum L., through foliar spraying with CaCl2 and Ca(NO3)2 solutions. In this context, soil heterogeneity of three potato-growing fields, as well as the implications of Ca accumulation among tissues and some quality parameters were assessed. Three potato varieties (Agria, Picasso and Rossi) were grown in three production fields and during the life cycle, four pulverizations with calcium chloride (3 and 6 kg ha−1) or calcium nitrate (0.5, 2 and 4 kg ha−1) were applied. For screening the potential phytotoxicity, using Agria as a test system, the potential synthesis of photoassimilates was determined, and it was found that after the 3rd Ca application, leaf gas exchanges were moderately (net photosynthesis), to strongly (stomatal conductance) affected, although without impact on Ca accumulation in tubers. At harvest, the average Ca biofortification index varied between 5–40%, 40–35% and 4.3–13% in Agria, Picasso and Rossi, respectively. Moreover, the equatorial region of the tubers in general showed that Ca accumulation prevailed in the epidermis and, in some cases, in inner areas of the potato tubers. Biofortified tubers with Ca also showed some significant changes in total soluble solids and colorimetric parameters. It is concluded that Ca enrichment of potato tubers through foliar spraying complemented the xylem mass flow of Ca from roots, through phloem redistribution. Both fertilizers showed similar efficiency, but Rossi revealed a lower index of Ca accumulation, eventually due to different metabolic characteristics. Although affected by Ca enrichment, potato tubers maintained a high quality for industrial processing. Full article
(This article belongs to the Special Issue Edible Plants)
►▼ Show Figures

Figure 1

21 pages, 3023 KiB  
Review
The Ubiquitin Switch in Plant Stress Response
by Paymon Doroodian and Zhihua Hua
Plants 2021, 10(2), 246; https://doi.org/10.3390/plants10020246 - 27 Jan 2021
Cited by 34 | Viewed by 4542
Abstract
Ubiquitin is a 76 amino acid polypeptide common to all eukaryotic organisms. It functions as a post-translationally modifying mark covalently linked to a large cohort of yet poorly defined protein substrates. The resulting ubiquitylated proteins can rapidly change their activities, cellular localization, or [...] Read more.
Ubiquitin is a 76 amino acid polypeptide common to all eukaryotic organisms. It functions as a post-translationally modifying mark covalently linked to a large cohort of yet poorly defined protein substrates. The resulting ubiquitylated proteins can rapidly change their activities, cellular localization, or turnover through the 26S proteasome if they are no longer needed or are abnormal. Such a selective modification is essential to many signal transduction pathways particularly in those related to stress responses by rapidly enhancing or quenching output. Hence, this modification system, the so-called ubiquitin-26S proteasome system (UPS), has caught the attention in the plant research community over the last two decades for its roles in plant abiotic and biotic stress responses. Through direct or indirect mediation of plant hormones, the UPS selectively degrades key components in stress signaling to either negatively or positively regulate plant response to a given stimulus. As a result, a tightly regulated signaling network has become of much interest over the years. The ever-increasing changes of the global climate require both the development of new crops to cope with rapid changing environment and new knowledge to survey the dynamics of ecosystem. This review examines how the ubiquitin can switch and tune plant stress response and poses potential avenues to further explore this system. Full article
(This article belongs to the Special Issue Role of the Ubiquitin System in Plant Stress Responses)
►▼ Show Figures

Figure 1

42 pages, 3447 KiB  
Review
Global Plant Virus Disease Pandemics and Epidemics
by Roger A. C. Jones
Plants 2021, 10(2), 233; https://doi.org/10.3390/plants10020233 - 25 Jan 2021
Cited by 163 | Viewed by 19511
Abstract
The world’s staple food crops, and other food crops that optimize human nutrition, suffer from global virus disease pandemics and epidemics that greatly diminish their yields and/or produce quality. This situation is becoming increasingly serious because of the human population’s growing food requirements [...] Read more.
The world’s staple food crops, and other food crops that optimize human nutrition, suffer from global virus disease pandemics and epidemics that greatly diminish their yields and/or produce quality. This situation is becoming increasingly serious because of the human population’s growing food requirements and increasing difficulties in managing virus diseases effectively arising from global warming. This review provides historical and recent information about virus disease pandemics and major epidemics that originated within different world regions, spread to other continents, and now have very wide distributions. Because they threaten food security, all are cause for considerable concern for humanity. The pandemic disease examples described are six (maize lethal necrosis, rice tungro, sweet potato virus, banana bunchy top, citrus tristeza, plum pox). The major epidemic disease examples described are seven (wheat yellow dwarf, wheat streak mosaic, potato tuber necrotic ringspot, faba bean necrotic yellows, pepino mosaic, tomato brown rugose fruit, and cucumber green mottle mosaic). Most examples involve long-distance virus dispersal, albeit inadvertent, by international trade in seed or planting material. With every example, the factors responsible for its development, geographical distribution and global importance are explained. Finally, an overall explanation is given of how to manage global virus disease pandemics and epidemics effectively. Full article
(This article belongs to the Special Issue Plant Virus Epidemiology)
►▼ Show Figures

Figure 1

16 pages, 5968 KiB  
Article
Effect of Three Nanoparticles (Se, Si and Cu) on the Bioactive Compounds of Bell Pepper Fruits under Saline Stress
by Yolanda González-García, Claribel Cárdenas-Álvarez, Gregorio Cadenas-Pliego, Adalberto Benavides-Mendoza, Marcelino Cabrera-de-la-Fuente, Alberto Sandoval-Rangel, Jesús Valdés-Reyna and Antonio Juárez-Maldonado
Plants 2021, 10(2), 217; https://doi.org/10.3390/plants10020217 - 23 Jan 2021
Cited by 51 | Viewed by 4527
Abstract
The bell pepper is a vegetable with high antioxidant content, and its consumption is important because it can reduce the risk of certain diseases in humans. Plants can be affected by different types of stress, whether biotic or abiotic. Among the abiotic factors, [...] Read more.
The bell pepper is a vegetable with high antioxidant content, and its consumption is important because it can reduce the risk of certain diseases in humans. Plants can be affected by different types of stress, whether biotic or abiotic. Among the abiotic factors, there is saline stress that affects the metabolism and physiology of plants, which causes damage, decreasing productivity and quality of fruits. The objective of this work was to evaluate the application of selenium, silicon and copper nanoparticles and saline stress on the bioactive compounds of bell pepper fruits. The bell pepper plants were exposed to saline stress (25 mM NaCl and 50 mM) in the nutrient solution throughout the crop cycle. The nanoparticles were applied drenching solution of these to substrate (Se NPs 10 and 50 mg L−1, Si NPs 200 and 1000 mg L−1, Cu NPs 100 and 500 mg L−1). The results show that saline stress reduces chlorophylls, lycopene, and β-carotene in leaves; but increased the activity of some enzymes (e.g., glutathione peroxidase and phenylalanine ammonia lyase, and glutathione). In fruits, saline stress decreased flavonoids and glutathione. The nanoparticles increased chlorophylls, lycopene and glutathione peroxidase activity in the leaves; and ascorbate peroxidase, glutathione peroxidase, catalase and phenylalanine ammonia lyase activity, and also phenols, flavonoids, glutathione, β-carotene, yellow carotenoids in fruits. The application of nanoparticles to bell pepper plants under saline stress is efficient to increase the content of bioactive compounds in fruits. Full article
(This article belongs to the Special Issue Nanotechnology Advances in Plant Science and Biotechnology)
►▼ Show Figures

Figure 1

27 pages, 2802 KiB  
Review
Bryo-Activities: A Review on How Bryophytes Are Contributing to the Arsenal of Natural Bioactive Compounds against Fungi
by Mauro Commisso, Francesco Guarino, Laura Marchi, Antonella Muto, Amalia Piro and Francesca Degola
Plants 2021, 10(2), 203; https://doi.org/10.3390/plants10020203 - 21 Jan 2021
Cited by 39 | Viewed by 9218
Abstract
Usually regarded as less evolved than their more recently diverged vascular sisters, which currently dominate vegetation landscape, bryophytes seem having nothing to envy to the defensive arsenal of other plants, since they had acquired a suite of chemical traits that allowed them to [...] Read more.
Usually regarded as less evolved than their more recently diverged vascular sisters, which currently dominate vegetation landscape, bryophytes seem having nothing to envy to the defensive arsenal of other plants, since they had acquired a suite of chemical traits that allowed them to adapt and persist on land. In fact, these closest modern relatives of the ancestors to the earliest terrestrial plants proved to be marvelous chemists, as they traditionally were a popular remedy among tribal people all over the world, that exploit their pharmacological properties to cure the most different diseases. The phytochemistry of bryophytes exhibits a stunning assortment of biologically active compounds such as lipids, proteins, steroids, organic acids, alcohols, aliphatic and aromatic compounds, polyphenols, terpenoids, acetogenins and phenylquinones, thus it is not surprising that substances obtained from various species belonging to such ancestral plants are widely employed as antitumor, antipyretic, insecticidal and antimicrobial. This review explores in particular the antifungal potential of the three Bryophyta divisions—mosses (Musci), hornworts (Anthocerotae) and liverworts (Hepaticae)—to be used as a sources of interesting bioactive constituents for both pharmaceutical and agricultural areas, providing an updated overview of the latest relevant insights. Full article
(This article belongs to the Special Issue Fungal Model Systems: What Can They Tell Us about the Biological Activity of Plant Extracts and Natural Compounds?)
►▼ Show Figures

Figure 1

25 pages, 3104 KiB  
Article
Zinc Enrichment in Two Contrasting Genotypes of Triticum aestivum L. Grains: Interactions between Edaphic Conditions and Foliar Fertilizers
by Inês Carmo Luís, Fernando C. Lidon, Cláudia Campos Pessoa, Ana Coelho Marques, Ana Rita F. Coelho, Manuela Simões, Manuel Patanita, José Dôres, José C. Ramalho, Maria Manuela Silva, Ana Sofia Almeida, Isabel P. Pais, Maria Fernanda Pessoa, Fernando Henrique Reboredo, Paulo Legoinha, Mauro Guerra, Roberta G. Leitão and Paula Scotti Campos
Plants 2021, 10(2), 204; https://doi.org/10.3390/plants10020204 - 21 Jan 2021
Cited by 20 | Viewed by 2636
Abstract
This study aimed to assess the implications of Zn enrichment in wheat grains as a function of contrasting genotypes, edaphic conditions and foliar fertilizers. Triticum aestivum L. varieties Roxo and Paiva were grown in four production fields, and sprayed with ZnSO4 (0, [...] Read more.
This study aimed to assess the implications of Zn enrichment in wheat grains as a function of contrasting genotypes, edaphic conditions and foliar fertilizers. Triticum aestivum L. varieties Roxo and Paiva were grown in four production fields, and sprayed with ZnSO4 (0, 16.20 and 36.40 kg/ha) Zn-EDTA (0, 6.30 and 12.60 kg/ha) and Tecnifol Zinc (0, 3.90 and 7.80 kg/ha). The heterogeneous edaphic conditions of the wheat fields were chemically characterized, it being found that soil properties determine different Zn accumulation in the grains of both genotypes. Foliar spraying enhanced to different extents Zn content in the grains of both genotypes, but the average of enrichment indexes varied among the wheat fields. Zinc mostly accumulated in the embryo and vascular bundle and to a lesser extent in the endosperm. Grain yield and test weight sprayed by ZnSO4 gave the highest values in both genotypes, but the opposite was found for Zn-EDTA. Considering the color parameters, lightness and red–green transitions were found to be a conjunction of genotype characteristics, fertilization types and edaphic conditions prevailing in each field. It is concluded that the index of Zn enrichment in wheat grains is a docket of edaphic conditions, genotype and type of fertilization. Full article
(This article belongs to the Collection Plant Nutrition Biofortification)
►▼ Show Figures

Figure 1

19 pages, 1119 KiB  
Review
Abiotic Stress in Crop Species: Improving Tolerance by Applying Plant Metabolites
by Francisca Godoy, Karina Olivos-Hernández, Claudia Stange and Michael Handford
Plants 2021, 10(2), 186; https://doi.org/10.3390/plants10020186 - 20 Jan 2021
Cited by 119 | Viewed by 18650
Abstract
Reductions in crop yields brought about by abiotic stress are expected to increase as climate change, and other factors, generate harsher environmental conditions in regions traditionally used for cultivation. Although breeding and genetically modified and edited organisms have generated many varieties with greater [...] Read more.
Reductions in crop yields brought about by abiotic stress are expected to increase as climate change, and other factors, generate harsher environmental conditions in regions traditionally used for cultivation. Although breeding and genetically modified and edited organisms have generated many varieties with greater abiotic stress tolerance, their practical use depends on lengthy processes, such as biological cycles and legal aspects. On the other hand, a non-genetic approach to improve crop yield in stress conditions involves the exogenous application of natural compounds, including plant metabolites. In this review, we examine the recent literature related to the application of different natural primary (proline, l-tryptophan, glutathione, and citric acid) and secondary (polyols, ascorbic acid, lipoic acid, glycine betaine, α-tocopherol, and melatonin) plant metabolites in improving tolerance to abiotic stress. We focus on drought, saline, heavy metal, and temperature as environmental parameters that are forecast to become more extreme or frequent as the climate continues to alter. The benefits of such applications are often evaluated by measuring their effects on metabolic, biochemical, and morphological parameters in a variety of crop plants, which usually result in improved yields when applied in greenhouse conditions or in the field. As this strategy has proven to be an effective way to raise plant tolerance to abiotic stress, we also discuss the prospect of its widespread implementation in the short term. Full article
(This article belongs to the Special Issue Plant Metabolites and Regulation under Environmental Stress)
►▼ Show Figures

Figure 1

17 pages, 3963 KiB  
Article
Evaluation of the Impact of Cold Atmospheric Pressure Plasma on Soybean Seed Germination
by Renáta Švubová, Ľudmila Slováková, Ľudmila Holubová, Dominika Rovňanová, Eliška Gálová and Juliána Tomeková
Plants 2021, 10(1), 177; https://doi.org/10.3390/plants10010177 - 19 Jan 2021
Cited by 35 | Viewed by 4562
Abstract
The present study aims to define the effects of Cold Atmospheric Pressure Plasma (CAPP) exposure on seed germination of an agriculturally important crop, soybean. Seed treatment with lower doses of CAPP generated in ambient air and oxygen significantly increased the activity of succinate [...] Read more.
The present study aims to define the effects of Cold Atmospheric Pressure Plasma (CAPP) exposure on seed germination of an agriculturally important crop, soybean. Seed treatment with lower doses of CAPP generated in ambient air and oxygen significantly increased the activity of succinate dehydrogenase (Krebs cycle enzyme), proving the switching of the germinating seed metabolism from anoxygenic to oxygenic. In these treatments, a positive effect on seed germination was documented (the percentage of germination increased by almost 20% compared to the untreated control), while the seed and seedling vigour was also positively affected. On the other hand, higher exposure times of CAPP generated in a nitrogen atmosphere significantly inhibited succinate dehydrogenase activity, but stimulated lactate and alcohol dehydrogenase activities, suggesting anoxygenic metabolism. It was also found that plasma exposure caused a slight increment in the level of primary DNA damage in ambient air- and oxygen-CAPP treatments, and more significant DNA damage was found in nitrogen-CAPP treatments. Although a higher level of DNA damage was also detected in the negative control (untreated seeds), this might be associated with the age of seeds followed by their lower germination capacity (with the germination percentage reaching only about 60%). Full article
(This article belongs to the Section Plant Physiology and Metabolism)
►▼ Show Figures

Figure 1

28 pages, 2430 KiB  
Review
The Past, Present and Future of Cannabis sativa Tissue Culture
by Adrian S. Monthony, Serena R. Page, Mohsen Hesami and Andrew Maxwell P. Jones
Plants 2021, 10(1), 185; https://doi.org/10.3390/plants10010185 - 19 Jan 2021
Cited by 63 | Viewed by 24301
Abstract
The recent legalization of Cannabis sativa L. in many regions has revealed a need for effective propagation and biotechnologies for the species. Micropropagation affords researchers and producers methods to rapidly propagate insect-/disease-/virus-free clonal plants and store germplasm and forms the basis for other [...] Read more.
The recent legalization of Cannabis sativa L. in many regions has revealed a need for effective propagation and biotechnologies for the species. Micropropagation affords researchers and producers methods to rapidly propagate insect-/disease-/virus-free clonal plants and store germplasm and forms the basis for other biotechnologies. Despite this need, research in the area is limited due to the long history of prohibitions and restrictions. Existing literature has multiple limitations: many publications use hemp as a proxy for drug-type Cannabis when it is well established that there is significant genotype specificity; studies using drug-type cultivars are predominantly optimized using a single cultivar; most protocols have not been replicated by independent groups, and some attempts demonstrate a lack of reproducibility across genotypes. Due to culture decline and other problems, the multiplication phase of micropropagation (Stage 2) has not been fully developed in many reports. This review will provide a brief background on the history and botany of Cannabis as well as a comprehensive and critical summary of Cannabis tissue culture. Special attention will be paid to current challenges faced by researchers, the limitations of existing Cannabis micropropagation studies, and recent developments and future directions of Cannabis tissue culture technologies. Full article
(This article belongs to the Special Issue Genetics and Functional Genomics in Cannabis sativa, L.)
►▼ Show Figures

Figure 1

14 pages, 765 KiB  
Article
Effect of Lead and Copper on Photosynthetic Apparatus in Citrus (Citrus aurantium L.) Plants. The Role of Antioxidants in Oxidative Damage as a Response to Heavy Metal Stress
by Anastasia Giannakoula, Ioannis Therios and Christos Chatzissavvidis
Plants 2021, 10(1), 155; https://doi.org/10.3390/plants10010155 - 14 Jan 2021
Cited by 127 | Viewed by 5927
Abstract
Photosynthetic changes and antioxidant activity to oxidative stress were evaluated in sour orange (Citrus aurantium L.) leaves subjected to lead (Pb), copper (Cu) and also Pb + Cu toxicity treatments, in order to elucidate the mechanisms involved in heavy metal tolerance. The [...] Read more.
Photosynthetic changes and antioxidant activity to oxidative stress were evaluated in sour orange (Citrus aurantium L.) leaves subjected to lead (Pb), copper (Cu) and also Pb + Cu toxicity treatments, in order to elucidate the mechanisms involved in heavy metal tolerance. The simultaneous effect of Pb− and Cu on growth, concentration of malondialdehyde (MDA), hydrogen peroxide (H2O2), chlorophylls, flavonoids, carotenoids, phenolics, chlorophyll fluorescence and photosynthetic parameters were examined in leaves of Citrus aurantium L. plants. Exogenous application of Pb and Cu resulted in an increase in leaf H2O2 and lipid peroxidation (MDA). Toxicity symptoms of both Pb and Cu treated plants were stunted growth and decreased pigments concentration. Furthermore, photosynthetic activity of treated plants exhibited a significant decline. The inhibition of growth in Pb and Cu-treated plants was accompanied by oxidative stress, as indicated by the enhanced lipid peroxidation and the high H2O2 concentration. Furthermore, antioxidants in citrus plants after exposure to high Pb and Cu concentrations were significantly increased compared to control and low Pb and Cu treatments. In conclusion, this study indicates that Pb and Cu promote lipid peroxidation, disrupt membrane integrity, reduces growth and photosynthesis and inhibit mineral nutrition. Considering the potential for adverse human health effects associated with high concentrations of Pb and Cu contained in edible parts of citrus plants the study signals that it is important to conduct further research into the accessibility and uptake of the tested heavy metals in the soil and whether they pose risks to humans. Full article
(This article belongs to the Special Issue Effects of Abiotic Stress on Nutrient Absorption and Photosynthetic Rate of Plants)
►▼ Show Figures

Figure 1

14 pages, 3813 KiB  
Article
Key Genes in the Melatonin Biosynthesis Pathway with Circadian Rhythm Are Associated with Various Abiotic Stresses
by Hye-Ryun Ahn, Yu-Jin Kim, You-Jin Lim, Shucheng Duan, Seok-Hyun Eom and Ki-Hong Jung
Plants 2021, 10(1), 129; https://doi.org/10.3390/plants10010129 - 9 Jan 2021
Cited by 32 | Viewed by 3990
Abstract
Melatonin (N-acetyl-5-methoxytryptamine), a well-known animal hormone, is involved in several biological processes including circadian rhythm and the regulation of abiotic stress. A systematic understanding of the circadian regulation of melatonin biosynthesis-related genes has not been achieved in rice. In this study, [...] Read more.
Melatonin (N-acetyl-5-methoxytryptamine), a well-known animal hormone, is involved in several biological processes including circadian rhythm and the regulation of abiotic stress. A systematic understanding of the circadian regulation of melatonin biosynthesis-related genes has not been achieved in rice. In this study, key genes for all of the enzymes in the melatonin biosynthetic pathway that showed a peak of expression at night were identified by microarray data analysis and confirmed by qRT–PCR analysis. We further examined the expression patterns of the four genes under drought, salt, and cold stresses. The results showed that abiotic stresses, such as drought, salt, and cold, affected the expression patterns of melatonin biosynthetic genes. In addition, the circadian expression patterns of tryptophan decarboxylase (TDC), tryptamine 5-hydroxylase (T5H), and serotonin N-acetyltransferase (SNAT) genes in wild-type (WT) plants was damaged by the drought treatment under light and dark conditions. Conversely, N-acetylserotonin O-methyltransferase (ASMT) retained the circadian rhythm. The expression of ASMT was down-regulated by the rice gigantea (OsGI) mutation, suggesting the involvement of the melatonin biosynthetic pathway in the OsGI-mediated circadian regulation pathway. Taken together, our results provide clues to explain the relationship between circadian rhythms and abiotic stresses in the process of melatonin biosynthesis in rice. Full article
(This article belongs to the Special Issue Adaptation of Plants to Environmental Changes: Light and Temperature in Plant Development)
►▼ Show Figures

Figure 1

12 pages, 1123 KiB  
Article
Edible Chitosan/Propolis Coatings and Their Effect on Ripening, Development of Aspergillus flavus, and Sensory Quality in Fig Fruit, during Controlled Storage
by Pablo F. Aparicio-García, Rosa I. Ventura-Aguilar, Juan C. del Río-García, Mónica Hernández-López, Dagoberto Guillén-Sánchez, Dolores A. Salazar-Piña, Margarita de L. Ramos-García and Silvia Bautista-Baños
Plants 2021, 10(1), 112; https://doi.org/10.3390/plants10010112 - 7 Jan 2021
Cited by 26 | Viewed by 3154
Abstract
Biodegradable alternatives for the control of Aspergillus flavus in fig fruit were tested with the application of coatings based on chitosan (CS) and propolis (P). To potentiate the fungicidal effect, nanoparticles of these two (CSNPs and PNPs) were also considered. The objectives of [...] Read more.
Biodegradable alternatives for the control of Aspergillus flavus in fig fruit were tested with the application of coatings based on chitosan (CS) and propolis (P). To potentiate the fungicidal effect, nanoparticles of these two (CSNPs and PNPs) were also considered. The objectives of this research were to evaluate the effect of different formulations on: (a) the ripening process of the fig, (b) the incidence of A. flavus and the production of aflatoxins, and (c) the acceptance of the treated fruit by a panel. The nanostructured coatings did not influence the ripening process of the fruit during the 12 days of storage, however, the antioxidant activity increased by approximately 30% with the coating CS + PNPs + P. The figs treated with CS + CSNPs + PNPs + P, inhibited the growth of the fungus by about 20% to 30% under laboratory and semi-commercial conditions. For all treatments, the aflatoxin production was lower than 20 ppb compared to the control with values of c.a. 250 ppb. The sensory quality was acceptable among the panel. The edible coatings can be a non-toxic alternative for post-harvest preservation and the consumption of fig fruit. The next step will be its inclusion and evaluation at a commercial level in packing houses. Full article
(This article belongs to the Special Issue Natural Products for Plant Pest and Disease Control)
►▼ Show Figures

Figure 1

40 pages, 9469 KiB  
Review
Impact of Environmental Factors on Stilbene Biosynthesis
by Alessio Valletta, Lorenzo Maria Iozia and Francesca Leonelli
Plants 2021, 10(1), 90; https://doi.org/10.3390/plants10010090 - 4 Jan 2021
Cited by 92 | Viewed by 8265
Abstract
Stilbenes are a small family of polyphenolic secondary metabolites that can be found in several distantly related plant species. These compounds act as phytoalexins, playing a crucial role in plant defense against phytopathogens, as well as being involved in the adaptation of plants [...] Read more.
Stilbenes are a small family of polyphenolic secondary metabolites that can be found in several distantly related plant species. These compounds act as phytoalexins, playing a crucial role in plant defense against phytopathogens, as well as being involved in the adaptation of plants to abiotic environmental factors. Among stilbenes, trans-resveratrol is certainly the most popular and extensively studied for its health properties. In recent years, an increasing number of stilbene compounds were subjected to investigations concerning their bioactivity. This review presents the most updated knowledge of the stilbene biosynthetic pathway, also focusing on the role of several environmental factors in eliciting stilbenes biosynthesis. The effects of ultraviolet radiation, visible light, ultrasonication, mechanical stress, salt stress, drought, temperature, ozone, and biotic stress are reviewed in the context of enhancing stilbene biosynthesis, both in planta and in plant cell and organ cultures. This knowledge may shed some light on stilbene biological roles and represents a useful tool to increase the accumulation of these valuable compounds. Full article
(This article belongs to the Special Issue Biosynthesis Pathways and Regulation Mechanism of Plants Secondary Metabolites)
►▼ Show Figures

Graphical abstract

19 pages, 788 KiB  
Review
RNA-Based Technologies for Engineering Plant Virus Resistance
by Michael Taliansky, Viktoria Samarskaya, Sergey K. Zavriev, Igor Fesenko, Natalia O. Kalinina and Andrew J. Love
Plants 2021, 10(1), 82; https://doi.org/10.3390/plants10010082 - 2 Jan 2021
Cited by 31 | Viewed by 6943
Abstract
In recent years, non-coding RNAs (ncRNAs) have gained unprecedented attention as new and crucial players in the regulation of numerous cellular processes and disease responses. In this review, we describe how diverse ncRNAs, including both small RNAs and long ncRNAs, may be used [...] Read more.
In recent years, non-coding RNAs (ncRNAs) have gained unprecedented attention as new and crucial players in the regulation of numerous cellular processes and disease responses. In this review, we describe how diverse ncRNAs, including both small RNAs and long ncRNAs, may be used to engineer resistance against plant viruses. We discuss how double-stranded RNAs and small RNAs, such as artificial microRNAs and trans-acting small interfering RNAs, either produced in transgenic plants or delivered exogenously to non-transgenic plants, may constitute powerful RNA interference (RNAi)-based technology that can be exploited to control plant viruses. Additionally, we describe how RNA guided CRISPR-CAS gene-editing systems have been deployed to inhibit plant virus infections, and we provide a comparative analysis of RNAi approaches and CRISPR-Cas technology. The two main strategies for engineering virus resistance are also discussed, including direct targeting of viral DNA or RNA, or inactivation of plant host susceptibility genes. We also elaborate on the challenges that need to be overcome before such technologies can be broadly exploited for crop protection against viruses. Full article
(This article belongs to the Special Issue Advances in Engineering Virus-Resistant Plants)
►▼ Show Figures

Figure 1

19 pages, 2136 KiB  
Review
Somatic Embryogenesis in Centaurium erythraea Rafn—Current Status and Perspectives: A Review
by Ana D. Simonović, Milana M. Trifunović-Momčilov, Biljana K. Filipović, Marija P. Marković, Milica D. Bogdanović and Angelina R. Subotić
Plants 2021, 10(1), 70; https://doi.org/10.3390/plants10010070 - 31 Dec 2020
Cited by 18 | Viewed by 4237
Abstract
Centaurium erythraea (centaury) is a traditionally used medicinal plant, with a spectrum of secondary metabolites with confirmed healing properties. Centaury is an emerging model in plant developmental biology due to its vigorous regenerative potential and great developmental plasticity when cultured in vitro. Hereby, [...] Read more.
Centaurium erythraea (centaury) is a traditionally used medicinal plant, with a spectrum of secondary metabolites with confirmed healing properties. Centaury is an emerging model in plant developmental biology due to its vigorous regenerative potential and great developmental plasticity when cultured in vitro. Hereby, we review nearly two decades of research on somatic embryogenesis (SE) in centaury. During SE, somatic cells are induced by suitable culture conditions to express their totipotency, acquire embryogenic characteristics, and eventually give rise to somatic embryos. When SE is initiated from centaury root explants, the process occurs spontaneously (on hormone-free medium), directly (without the callusing phase), and the somatic embryos are of unicellular origin. SE from leaf explants has to be induced by plant growth regulators and is indirect (preceded by callusing). Histological observations and culture conditions are compared in these two systems. The changes in antioxidative enzymes were followed during SE from the leaf explants. Special focus is given to the role of arabinogalactan proteins during SE, which were analyzed using a variety of approaches. The newest and preliminary results, including centaury transcriptome, novel potential SE markers, and novel types of arabinogalactan proteins, are discussed as perspectives of centaury research. Full article
(This article belongs to the Special Issue Plant Embryogenesis)
►▼ Show Figures

Figure 1

20 pages, 3812 KiB  
Review
Agronomic Practices and Performances of Quinoa under Field Conditions: A Systematic Review
by Mohamed Houssemeddine Sellami, Cataldo Pulvento and Antonella Lavini
Plants 2021, 10(1), 72; https://doi.org/10.3390/plants10010072 - 31 Dec 2020
Cited by 28 | Viewed by 4000
Abstract
Quinoa (Chenopodium quinoa Willd.) is one of the most popular emerging food crops in the Andean region. It is tolerant to environmental stresses and characterized by interesting nutritional traits. Thus, it has the potential to contribute to food and nutrition security in [...] Read more.
Quinoa (Chenopodium quinoa Willd.) is one of the most popular emerging food crops in the Andean region. It is tolerant to environmental stresses and characterized by interesting nutritional traits. Thus, it has the potential to contribute to food and nutrition security in marginal environments. In this study, we conducted a systematic review integrated with a bibliometric analysis of cropping practices of quinoa under field conditions. The analysis is based on published data from the literature relating to the period 2000–2020. A total of 33 publications were identified, revealing that scientific research on the agronomic practices and performances of quinoa under field conditions is still limited. Africa, Asia, and Europe were the leading research production sites in this field and together provided over 81% of the total scientific production. There were no papers from the Australian continent. The number of papers screened dealing with tillage and weed control management was very limited. The keyword co-occurrence network analyses revealed that the main topics addressed in the scientific literature related to the effect of “variety” and “deficit irrigation”, followed by “water quality”, “fertilization”, and “sowing date” on seed yield. Results from this study will permit us to identify knowledge gaps and limited collaboration among authors and institutions from different countries. Salinity, sowing density, and sowing date were the agronomic interventions affecting productive response the most. Full article
(This article belongs to the Special Issue Worldwide Evaluations of Quinoa—Biodiversity and Food Security under Climate Change Pressures)
►▼ Show Figures

Figure 1

17 pages, 857 KiB  
Article
Antioxidant, Anti-tyrosinase, Anti-α-amylase, and Cytotoxic Potentials of the Invasive Weed Andropogon virginicus
by La Hoang Anh, Nguyen Van Quan, Vu Quang Lam, Yu Iuchi, Akiyoshi Takami, Rolf Teschke and Tran Dang Xuan
Plants 2021, 10(1), 69; https://doi.org/10.3390/plants10010069 - 31 Dec 2020
Cited by 15 | Viewed by 6409
Abstract
Andropogon virginicus is an invasive weed that seriously threatens agricultural production and economics worldwide. In this research, dried aerial parts of A. virginicus were extracted, applying Soxhlet and liquid-liquid phase methods to acquire the total crude (T-Anvi), hexane (H-Anvi), ethyl acetate (E-Anvi), butanol [...] Read more.
Andropogon virginicus is an invasive weed that seriously threatens agricultural production and economics worldwide. In this research, dried aerial parts of A. virginicus were extracted, applying Soxhlet and liquid-liquid phase methods to acquire the total crude (T-Anvi), hexane (H-Anvi), ethyl acetate (E-Anvi), butanol (B-Anvi), and water (W-Anvi) extracts, respectively. In which, T-Anvi contains the highest total phenolic and flavonoid contents (24.80 mg gallic acid and 37.40 mg rutin equivalents per g dry weight, respectively). Via anti-radical (ABTS and DPPH), and reducing power assays, E-Anvi exhibits the most potent activities (IC50 = 13.96, 43.59 and 124.11 µg/mL, respectively), stronger than butylated hydroxytoluene (BHT), a standard antioxidant, while the lipid peroxidation inhibitory effect of E-Anvi (LPI = 90.85% at the concentration of 500 µg/mL) is close to BHT. E-Anvi shows the most substantial inhibition (IC50 = 2.58 mg/mL) on tyrosinase. Notably, α-amylase is significantly suppressed by H-Anvi (IC50 = 0.72 mg/mL), over twice stronger than the positive control, palmitic acid. In the cytotoxic assay, E-Anvi is the strongest extract inhibiting K562 cells (IC50 = 112.01 µg/mL). Meanwhile, T-Anvi shows the highest prevention on Meg-01 expansion (IC50 = 91.40 µg/mL). Dominant compounds detected in E-Anvi by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) are identified as flavonoids. However, among four major compounds identified in H-Anvi by gas chromatography-mass spectrometry (GC-MS), palmitic acid and phytol are the most abundant compounds with peak areas of 27.97% and 16.42%, respectively. In essence, this is the first report describing that A. virginicus is a potential natural source of antioxidants, tyrosinase and α-amylase inhibitors, and anti-chronic myeloid leukemia (CML) agents which may be useful in future therapeutics as promising alternative medicines. Full article
(This article belongs to the Special Issue Biological Activities of Plant Extracts)
►▼ Show Figures

Figure 1

19 pages, 1023 KiB  
Review
The Genus Curcuma and Inflammation: Overview of the Pharmacological Perspectives
by Md. Moshiur Rahaman, Ahmed Rakib, Saikat Mitra, Abu Montakim Tareq, Talha Bin Emran, A. F. M. Shahid-Ud-Daula, Mohammad Nurul Amin and Jesus Simal-Gandara
Plants 2021, 10(1), 63; https://doi.org/10.3390/plants10010063 - 30 Dec 2020
Cited by 40 | Viewed by 6777
Abstract
The Curcuma genus has been extensively used for therapeutic purposes in traditional or folk medicine worldwide, including for its anti-inflammatory activity. Curcuma spp.’s active constituents, such as alkaloids, flavonoids, and terpenoids, can act on various targets in the signaling pathway, restrain pro-inflammatory enzymes, [...] Read more.
The Curcuma genus has been extensively used for therapeutic purposes in traditional or folk medicine worldwide, including for its anti-inflammatory activity. Curcuma spp.’s active constituents, such as alkaloids, flavonoids, and terpenoids, can act on various targets in the signaling pathway, restrain pro-inflammatory enzymes, lower the production of inflammatory cytokines and chemokines, and reduce oxidative stress, which subsequently suppresses inflammatory processes. Preclinical and clinical studies have reported the predominant anti-inflammatory activity of several Curcuma species. This review provides an overview of the anti-inflammatory effects of different extracts, preparations, and bioactive components in this genus. This analysis may provide a scientific basis for developing new and alternative methods for the isolation of a single entity from this genus to attenuate inflammatory conditions. The Curcuma genus is waiting for researchers interested in developing safe and efficient anti-inflammatory agents for further investigation. Full article
►▼ Show Figures

Figure 1

31 pages, 960 KiB  
Review
Curcuma longa L. Rhizome Essential Oil from Extraction to Its Agri-Food Applications. A Review
by María Dolores Ibáñez and María Amparo Blázquez
Plants 2021, 10(1), 44; https://doi.org/10.3390/plants10010044 - 28 Dec 2020
Cited by 59 | Viewed by 9953
Abstract
Curcuma longa L. rhizome essential oil is a valuable product in pharmaceutical industry due to its wide beneficial health effects. Novel applications in the agri-food industry where more sustainable extraction processes are required currently and safer substances are claimed for the consumer are [...] Read more.
Curcuma longa L. rhizome essential oil is a valuable product in pharmaceutical industry due to its wide beneficial health effects. Novel applications in the agri-food industry where more sustainable extraction processes are required currently and safer substances are claimed for the consumer are being investigated. This review provides information regarding the conventional and recent extraction methods of C. longa rhizome oil, their characteristics and suitability to be applied at the industrial scale. In addition, variations in the chemical composition of C. longa rhizome and leaf essential oils regarding intrinsic and extrinsic factors and extraction methods are also analysed in order to select the most proper to obtain the most efficient activity. Finally, the potential applications of C. longa rhizome oil in the agri-food industry, such as antimicrobial, weedicide and a food preservative agent, are included. Regarding the data, C. longa rhizome essential oil may play a special role in the agri-food industry; however, further research to determine the application threshold so as not to damage crops or affect the organoleptic properties of food products, as well as efficient encapsulation techniques, are necessary for its implementation in global agriculture. Full article
(This article belongs to the Special Issue Plant Essential Oil with Biological Activity)
►▼ Show Figures

Graphical abstract

24 pages, 4375 KiB  
Review
Rising Atmospheric Temperature Impact on Wheat and Thermotolerance Strategies
by Adeel Khan, Munir Ahmad, Mukhtar Ahmed and M. Iftikhar Hussain
Plants 2021, 10(1), 43; https://doi.org/10.3390/plants10010043 - 27 Dec 2020
Cited by 42 | Viewed by 5524
Abstract
Temperature across the globe is increasing continuously at the rate of 0.15–0.17 °C per decade since the industrial revolution. It is influencing agricultural crop productivity. Therefore, thermotolerance strategies are needed to have sustainability in crop yield under higher temperature. However, improving thermotolerance in [...] Read more.
Temperature across the globe is increasing continuously at the rate of 0.15–0.17 °C per decade since the industrial revolution. It is influencing agricultural crop productivity. Therefore, thermotolerance strategies are needed to have sustainability in crop yield under higher temperature. However, improving thermotolerance in the crop is a challenging task for crop scientists. Therefore, this review work was conducted with the aim of providing information on the wheat response in three research areas, i.e., physiology, breeding, and advances in genetics, which could assist the researchers in improving thermotolerance. The optimum temperature for wheat growth at the heading, anthesis, and grain filling duration is 16 ± 2.3 °C, 23 ± 1.75 °C, and 26 ± 1.53 °C, respectively. The high temperature adversely influences the crop phenology, growth, and development. The pre-anthesis high temperature retards the pollen viability, seed formation, and embryo development. The post-anthesis high temperature declines the starch granules accumulation, stem reserve carbohydrates, and translocation of photosynthates into grains. A high temperature above 40 °C inhibits the photosynthesis by damaging the photosystem-II, electron transport chain, and photosystem-I. Our review work highlighted that genotypes which can maintain a higher accumulation of proline, glycine betaine, expression of heat shock proteins, stay green and antioxidant enzymes activity viz., catalase, peroxidase, super oxide dismutase, and glutathione reductase can tolerate high temperature efficiently through sustaining cellular physiology. Similarly, the pre-anthesis acclimation with heat treatment, inorganic fertilizer such as nitrogen, potassium nitrate and potassium chloride, mulches with rice husk, early sowing, presoaking of a 6.6 mM solution of thiourea, foliar application of 50 ppm dithiothreitol, 10 mg per kg of silicon at heading and zinc ameliorate the crop against the high temperature. Finally, it has been suggested that modern genomics and omics techniques should be used to develop thermotolerance in wheat. Full article
(This article belongs to the Special Issue Plant Responses to Biotic and Abiotic Stresses: Crosstalk between Biochemistry and Ecophysiology)
►▼ Show Figures

Figure 1

17 pages, 1581 KiB  
Review
Seed Priming with Phytohormones: An Effective Approach for the Mitigation of Abiotic Stress
by Mohammad Saidur Rhaman, Shahin Imran, Farjana Rauf, Mousumi Khatun, Carol C. Baskin, Yoshiyuki Murata and Mirza Hasanuzzaman
Plants 2021, 10(1), 37; https://doi.org/10.3390/plants10010037 - 25 Dec 2020
Cited by 150 | Viewed by 13497
Abstract
Plants are often exposed to abiotic stresses such as drought, salinity, heat, cold, and heavy metals that induce complex responses, which result in reduced growth as well as crop yield. Phytohormones are well known for their regulatory role in plant growth and development, [...] Read more.
Plants are often exposed to abiotic stresses such as drought, salinity, heat, cold, and heavy metals that induce complex responses, which result in reduced growth as well as crop yield. Phytohormones are well known for their regulatory role in plant growth and development, and they serve as important chemical messengers, allowing plants to function during exposure to various stresses. Seed priming is a physiological technique involving seed hydration and drying to improve metabolic processes prior to germination, thereby increasing the percentage and rate of germination and improving seedling growth and crop yield under normal and various biotic and abiotic stresses. Seed priming allows plants to obtain an enhanced capacity for rapidly and effectively combating different stresses. Thus, seed priming with phytohormones has emerged as an important tool for mitigating the effects of abiotic stress. Therefore, this review discusses the potential role of priming with phytohormones to mitigate the harmful effects of abiotic stresses, possible mechanisms for how mitigation is accomplished, and roles of priming on the enhancement of crop production. Full article
(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)
►▼ Show Figures

Figure 1

14 pages, 3855 KiB  
Article
Detection of Strawberry Diseases Using a Convolutional Neural Network
by Jia-Rong Xiao, Pei-Che Chung, Hung-Yi Wu, Quoc-Hung Phan, Jer-Liang Andrew Yeh and Max Ti-Kuang Hou
Plants 2021, 10(1), 31; https://doi.org/10.3390/plants10010031 - 25 Dec 2020
Cited by 61 | Viewed by 6578
Abstract
The strawberry (Fragaria × ananassa Duch.) is a high-value crop with an annual cultivated area of ~500 ha in Taiwan. Over 90% of strawberry cultivation is in Miaoli County. Unfortunately, various diseases significantly decrease strawberry production. The leaf and fruit disease became [...] Read more.
The strawberry (Fragaria × ananassa Duch.) is a high-value crop with an annual cultivated area of ~500 ha in Taiwan. Over 90% of strawberry cultivation is in Miaoli County. Unfortunately, various diseases significantly decrease strawberry production. The leaf and fruit disease became an epidemic in 1986. From 2010 to 2016, anthracnose crown rot caused the loss of 30–40% of seedlings and ~20% of plants after transplanting. The automation of agriculture and image recognition techniques are indispensable for detecting strawberry diseases. We developed an image recognition technique for the detection of strawberry diseases using a convolutional neural network (CNN) model. CNN is a powerful deep learning approach that has been used to enhance image recognition. In the proposed technique, two different datasets containing the original and feature images are used for detecting the following strawberry diseases—leaf blight, gray mold, and powdery mildew. Specifically, leaf blight may affect the crown, leaf, and fruit and show different symptoms. By using the ResNet50 model with a training period of 20 epochs for 1306 feature images, the proposed CNN model achieves a classification accuracy rate of 100% for leaf blight cases affecting the crown, leaf, and fruit; 98% for gray mold cases, and 98% for powdery mildew cases. In 20 epochs, the accuracy rate of 99.60% obtained from the feature image dataset was higher than that of 1.53% obtained from the original one. This proposed model provides a simple, reliable, and cost-effective technique for detecting strawberry diseases. Full article
►▼ Show Figures

Graphical abstract

20 pages, 4738 KiB  
Article
Confirmation and Fine Mapping of the Resistance Locus Ren9 from the Grapevine Cultivar ‘Regent’
by Daniel Zendler, Reinhard Töpfer and Eva Zyprian
Plants 2021, 10(1), 24; https://doi.org/10.3390/plants10010024 - 24 Dec 2020
Cited by 20 | Viewed by 2987
Abstract
Grapevine (Vitis vinifera ssp. vinifera) is a major fruit crop with high economic importance. Due to its susceptibility towards fungal and oomycete pathogens such as Erysiphe necator and Plasmopara viticola, the causal agents of powdery and downy mildew (PM and DM, [...] Read more.
Grapevine (Vitis vinifera ssp. vinifera) is a major fruit crop with high economic importance. Due to its susceptibility towards fungal and oomycete pathogens such as Erysiphe necator and Plasmopara viticola, the causal agents of powdery and downy mildew (PM and DM, respectively), grapevine growers annually face a major challenge in coping with shortfalls of yield caused by these diseases. Here we report the confirmation of a genetic resource for grapevine resistance breeding against PM. During the delimitation process of Ren3 on chromosome 15 from the cultivar ‘Regent’, a second resistance-encoding region on chromosome 15 termed Ren9 was characterized. It mediates a trailing necrosis associated with the appressoria of E. necator and restricts pathogen growth. In this study, we confirm this QTL in a related mapping population of ‘Regent’ × ‘Cabernet Sauvignon’. The data show that this locus is located at the upper arm of chromosome 15 between markers GF15-58 (0.15 Mb) and GF15-53 (4 Mb). The efficiency of the resistance against one of the prominent European PM isolates (EU-B) is demonstrated. Based on fine-mapping and literature knowledge we propose two possible regions of interest and supply molecular markers to follow both regions in marker-assisted selection. Full article
(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)
►▼ Show Figures

Figure 1

27 pages, 1349 KiB  
Review
Nano-Fertilization as an Emerging Fertilization Technique: Why Can Modern Agriculture Benefit from Its Use?
by Mahmoud F. Seleiman, Khalid F. Almutairi, Majed Alotaibi, Ashwag Shami, Bushra Ahmed Alhammad and Martin Leonardo Battaglia
Plants 2021, 10(1), 2; https://doi.org/10.3390/plants10010002 - 22 Dec 2020
Cited by 267 | Viewed by 10505
Abstract
There is a need for a more innovative fertilizer approach that can increase the productivity of agricultural systems and be more environmentally friendly than synthetic fertilizers. In this article, we reviewed the recent development and potential benefits derived from the use of nanofertilizers [...] Read more.
There is a need for a more innovative fertilizer approach that can increase the productivity of agricultural systems and be more environmentally friendly than synthetic fertilizers. In this article, we reviewed the recent development and potential benefits derived from the use of nanofertilizers (NFs) in modern agriculture. NFs have the potential to promote sustainable agriculture and increase overall crop productivity, mainly by increasing the nutrient use efficiency (NUE) of field and greenhouse crops. NFs can release their nutrients at a slow and steady pace, either when applied alone or in combination with synthetic or organic fertilizers. They can release their nutrients in 40–50 days, while synthetic fertilizers do the same in 4–10 days. Moreover, NFs can increase the tolerance of plants against biotic and abiotic stresses. Here, the advantages of NFs over synthetic fertilizers, as well as the different types of macro and micro NFs, are discussed in detail. Furthermore, the application of NFs in smart sustainable agriculture and the role of NFs in the mitigation of biotic and abiotic stress on plants is presented. Though NF applications may have many benefits for sustainable agriculture, there are some concerns related to the release of nanoparticles (NPs) from NFs into the environment, with the subsequent detrimental effects that this could have on both human and animal health. Future research should explore green synthesized and biosynthesized NFs, their safe use, bioavailability, and toxicity concerns. Full article
(This article belongs to the Special Issue Plant Nutrition)
►▼ Show Figures

Figure 1

14 pages, 2890 KiB  
Article
Genotype × Environment Interaction for Wheat Yield Traits Suitable for Selection in Different Seed Priming Conditions
by Vera Popović, Nataša Ljubičić, Marko Kostić, Mirjana Radulović, Dragana Blagojević, Vladan Ugrenović, Dragana Popović and Bojana Ivošević
Plants 2020, 9(12), 1804; https://doi.org/10.3390/plants9121804 - 19 Dec 2020
Cited by 50 | Viewed by 3597
Abstract
Different seed priming treatments are widely used in order to improve the nutritional status of wheat, as well as to improve its grain yield and yield- related traits. The present study aimed to evaluate the impact of seed priming with zinc oxide nanoparticles [...] Read more.
Different seed priming treatments are widely used in order to improve the nutritional status of wheat, as well as to improve its grain yield and yield- related traits. The present study aimed to evaluate the impact of seed priming with zinc oxide nanoparticles (ZnO NPs) on the yield related traits, such as, field emergence, plant height, spike length and grain yield per plant of four winter wheat genotypes (Triticum aestivum L.) during two vegetation seasons of 2018/2019 and 2019/2020. The seeds of each wheat genotypes were primed with different concentrations of ZnO NPs (0 mg L−1, 10 mg L−1, 100 mg L−1 and 1000 mg L−1) for 48 h in a dark box by continuous aeration and were sown in soil pots with 60–70% moisture content until full maturity. The additive main effects and multiplicative interaction (AMMI) models were used to study the genotype environment effects. The results indicated that the plants response to ZnO nanoparticles significantly increased all of the observed traits of the wheat, while its maximum rates reduced the traits of the wheat. The AMMI analysis revealed the very complex nature of the variation observed in the trial and showed the significant effect of the G×E interaction, in which the first main component was significant for all components. Full article
(This article belongs to the Special Issue Wheat Crop Improvement (by Transgenic and Conventional Breeding Methods))
►▼ Show Figures

Figure 1

26 pages, 1747 KiB  
Review
Decoding Heavy Metal Stress Signalling in Plants: Towards Improved Food Security and Safety
by Marshall Keyster, Lee-Ann Niekerk, Gerhard Basson, Mogamat Carelse, Olalekan Bakare, Ndiko Ludidi, Ashwil Klein, Lukhanyo Mekuto and Arun Gokul
Plants 2020, 9(12), 1781; https://doi.org/10.3390/plants9121781 - 16 Dec 2020
Cited by 50 | Viewed by 5458
Abstract
The mining of heavy metals from the environment leads to an increase in soil pollution, leading to the uptake of heavy metals into plant tissue. The build-up of toxic metals in plant cells often leads to cellular damage and senescence. Therefore, it is [...] Read more.
The mining of heavy metals from the environment leads to an increase in soil pollution, leading to the uptake of heavy metals into plant tissue. The build-up of toxic metals in plant cells often leads to cellular damage and senescence. Therefore, it is of utmost importance to produce plants with improved tolerance to heavy metals for food security, as well as to limit heavy metal uptake for improved food safety purposes. To achieve this goal, our understanding of the signaling mechanisms which regulate toxic heavy metal uptake and tolerance in plants requires extensive improvement. In this review, we summarize recent literature and data on heavy metal toxicity (oral reference doses) and the impact of the metals on food safety and food security. Furthermore, we discuss some of the key events (reception, transduction, and response) in the heavy metal signaling cascades in the cell wall, plasma membrane, and cytoplasm. Our future perspectives provide an outlook of the exciting advances that will shape the plant heavy metal signaling field in the near future. Full article
(This article belongs to the Special Issue Heavy Metal Pollution and Plants Growth)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying article 651-700 on page 14 of 20.

Go to page    first_page chevron_left 12 13 14 15 16 chevron_right last_page
Back to TopTop