Plants

16 pages, 1179 KiB

Open AccessArticle

Application of Loop-Mediated Isothermal Amplification in an Early Warning System for Epidemics of an Externally Sourced Plant Virus

by Benjamin Congdon, Paul Matson, Farhana Begum, Monica Kehoe and Brenda Coutts

Plants 2019, 8(5), 139; https://doi.org/10.3390/plants8050139 - 27 May 2019

Cited by 16 | Viewed by 3094

Abstract

Restricting Turnip yellows virus (TuYV) spread in canola (Brassica napus) crops often relies upon the application of systemic insecticides to protect young vulnerable plants from wide-scale green-peach aphid (GPA; Myzus persicae) colonization and subsequent virus infection. For these to be [...] Read more.

Restricting Turnip yellows virus (TuYV) spread in canola (Brassica napus) crops often relies upon the application of systemic insecticides to protect young vulnerable plants from wide-scale green-peach aphid (GPA; Myzus persicae) colonization and subsequent virus infection. For these to be applied at the optimal time to ensure they prevent epidemics, growers would need to be forewarned of incoming viruliferous aphid migration and colonization. This study was conducted to field validate a loop-mediated isothermal amplification (LAMP) protocol designed to detect TuYV in aphids caught on traps and develop an early warning system for TuYV epidemics. Double-sided yellow sticky traps were deployed at 30 sites sown with canola over a two-year period in the south-west Australian grainbelt. Using LAMP, the percentage (%) of trap sides with TuYV-carrying aphids was measured and related to TuYV infection incidence in the adjacent crop. When TuYV was detected in aphids on >30% trap sides in a six-week period from pre-emergence to GS15 (five-leaf stage), TuYV reached >60% crop incidence by GS30 (beginning of stem elongation). Whereas, TuYV detection in aphids on ≤15% trap sides during this period was associated with ≤6% TuYV incidence by GS30. Furthermore, when large numbers of aphids, including GPA, were caught during this period but no TuYV was detected in them, minimal TuYV spread (≤5%) occurred in the crop by GS30. Therefore, the LAMP TuYV protocol can be used in an early warning system for TuYV epidemics by providing detection of initial viruliferous aphid migration into a canola crop before they establish colonies throughout the crop and spread virus. This would enable proactive, non-prophylactic, and thereby more effective systemic insecticide applications to minimize seed yield and quality losses due to early season TuYV infection. Full article

(This article belongs to the Special Issue Diagnosis and Control of Plant Viral Diseases)

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13 pages, 525 KiB

Open AccessArticle

Effect of Organic Inputs and Solarization for the Suppression of Rhizoctonia solani in Woody Ornamental Plant Production

by Fulya Baysal-Gurel, Md Niamul Kabir and Prabha Liyanapathiranage

Plants 2019, 8(5), 138; https://doi.org/10.3390/plants8050138 - 24 May 2019

Cited by 9 | Viewed by 3285

Abstract

Soilborne diseases are the most economically significant problem faced by Southern region nursery producers. The goal of this research was to improve Rhizoctonia root rot disease management through the use of soil solarization alone and in combination with biofumigant cover crops—arugula ‘Astro’ ( [...] Read more.

Soilborne diseases are the most economically significant problem faced by Southern region nursery producers. The goal of this research was to improve Rhizoctonia root rot disease management through the use of soil solarization alone and in combination with biofumigant cover crops—arugula ‘Astro’ (Eruca vesicaria ssp. sativa), mustard green ‘Amara’ (Brassica carinata), and turnip ‘Purple top forage’ (B. rapa); good quality compost and mustard meal amendment. The experiments were established as on-farm trials in 2016 and 2017 with prevalent Rhizoctonia solani population in propagation beds. All three biofumigant cover crops, arugula ‘Astro’, mustard green ‘Amara’, and turnip ‘Purple top forage’ in combination with solarization were able to reduce the Rhizoctonia root rot in flowering cherry ‘Kwanzan’ plants in nursery propagation beds. Compost amendment increased the flowering cherry rooted cuttings growth (plant weight, root weight, and plant height) compared to other treatments. Soil solarization in combination with cover crops and organic inputs could be used as part of an integrated approach to manage Rhizoctonia root rot in nursery crop propagation beds. Full article

(This article belongs to the Section Plant Protection and Biotic Interactions)

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12 pages, 1736 KiB

Open AccessArticle

Silicon Promotes Agronomic Performance in Brassica napus Cultivated under Field Conditions with Two Nitrogen Fertilizer Inputs

by Philippe Laîné, Cylia Haddad, Mustapha Arkoun, Jean-Claude Yvin and Philippe Etienne

Plants 2019, 8(5), 137; https://doi.org/10.3390/plants8050137 - 22 May 2019

Cited by 20 | Viewed by 4988

Abstract

To limit the environmental pollution associated with intensive nitrogen (N) fertilizer usage, alternative cultural practices must be considered for crops requiring high N inputs such as rapeseed. In this context, the effects of silicon (Si) supply on the agronomic performance of rapeseed cultivated [...] Read more.

To limit the environmental pollution associated with intensive nitrogen (N) fertilizer usage, alternative cultural practices must be considered for crops requiring high N inputs such as rapeseed. In this context, the effects of silicon (Si) supply on the agronomic performance of rapeseed cultivated under field conditions with two N fertilizer levels (60 and 160 kg ha⁻¹) were studied. Results showed that Si supplied in the form of silicic acid (12 kg ha⁻¹) has no effect on the agronomic performance of plants cultivated with the lower N input. In contrast, in plants fertilized with 160 kg N ha⁻¹, Si supply promotes the preservation of green leaves (until the flowering stage) and at harvest stage, increases biomass, yield, and seed micronutrient concentrations (especially cobalt and iron). The agronomic indexes show that the increase in seed yield is related to a better uptake of N from the soil by Si-treated plants, but is not an improvement in N mobilization towards the seeds. This study showed that Si supply combined with high N inputs (160 kg ha⁻¹) improves usage of N fertilizer and yield. The possibility that a Si supply could allow for a reduction in N input without altering the yield of rapeseed is discussed. Full article

(This article belongs to the Section Plant Physiology and Metabolism)

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11 pages, 251 KiB

Open AccessArticle

Impact of Foliar Fertilization on the Content of Silicon and Macronutrients in Sugar Beet

by Arkadiusz Artyszak, Dariusz Gozdowski and Katarzyna Kucińska

Plants 2019, 8(5), 136; https://doi.org/10.3390/plants8050136 - 22 May 2019

Cited by 11 | Viewed by 3285

Abstract

The present study was conducted to assess the effect of various multinutrient foliar fertilization treatments on nutrient accumulation in the roots and leaves of sugar beet. The field experiment was performed in two growing seasons (2013 and 2014) in the southeastern region of [...] Read more.

The present study was conducted to assess the effect of various multinutrient foliar fertilization treatments on nutrient accumulation in the roots and leaves of sugar beet. The field experiment was performed in two growing seasons (2013 and 2014) in the southeastern region of Poland. The experiment was conducted as a randomized block design with four replications. To determine the content of the selected nutrients (Si, N, P, K, Mg, and Ca), samples of leaves and roots were collected during harvest. Fertilization treatments applied on the plants’ leaves affected the silicon (Si) content in the roots of sugar beet and the total Si uptake. Moreover, foliar fertilization had a significant effect on the P content in the leaves and the N and K contents in the roots. The Si content in the sugar beet leaves and roots ranged from 0.55 to 1.97 g kg⁻¹ dry matter (d. m.) and from 0.49 to 1.59 g kg⁻¹ d. m., respectively. The total Si uptake ranged from 20.3 to 46.7 kg ha⁻¹. Most of the Si content taken up with each fertilization variant was accumulated in the roots. The yield of pure sugar was not correlated with the Si content in the leaves and roots. Full article

(This article belongs to the Section Plant Development and Morphogenesis)

15 pages, 3193 KiB

Open AccessArticle

Genome-Wide DNA Methylation Profiling in the Lotus (Nelumbo nucifera) Flower Showing its Contribution to the Stamen Petaloid

by Zhongyuan Lin, Meihui Liu, Rebecca Njeri Damaris, Tonny Maraga Nyong’a, Dingding Cao, Kefang Ou and Pingfang Yang

Plants 2019, 8(5), 135; https://doi.org/10.3390/plants8050135 - 20 May 2019

Cited by 17 | Viewed by 4245

Abstract

DNA methylation is a vital epigenetic modification. Methylation has a significant effect on the gene expression influencing the regulation of different physiological processes. Current studies on DNA methylation have been conducted on model plants. Lotus (Nelumbo nucifera) is a basic eudicot [...] Read more.

DNA methylation is a vital epigenetic modification. Methylation has a significant effect on the gene expression influencing the regulation of different physiological processes. Current studies on DNA methylation have been conducted on model plants. Lotus (Nelumbo nucifera) is a basic eudicot exhibiting variations during development, especially in flower formation. DNA methylation profiling was conducted on different flower tissues of lotuses through whole genome bisulfite sequencing (WGBS) to investigate the effects of DNA methylation on its stamen petaloid. A map of methylated cytosines at the single base pair resolution for the lotus was constructed. When the stamen was compared with the stamen petaloid, the DNA methylation exhibited a global decrease. Genome-wide relationship analysis between DNA methylation and gene expression identified 31 different methylation region (DMR)-associated genes, which might play crucial roles in floral organ formation, especially in the stamen petaloid. One out of 31 DMR-associated genes, NNU_05638 was homolog with Plant U-box 33 (PUB33). The DNA methylation status of NNU_05638 promoter was distinct in three floral organs, which was confirmed by traditional bisulfite sequencing. These results provide further insights about the regulation of stamen petaloids at the epigenetic level in lotus. Full article

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9 pages, 1643 KiB

Open AccessArticle

Allelopathic Potency and an Active Substance from Anredera cordifolia (Tenore) Steenis

by Ichsan Nurul Bari, Hisashi Kato-Noguchi, Arihiro Iwasaki and Kiyotake Suenaga

Plants 2019, 8(5), 134; https://doi.org/10.3390/plants8050134 - 18 May 2019

Cited by 20 | Viewed by 4319

Abstract

Anredera cordifolia (Tenore) Steenis is widely planted as an ornamental and medicinal plant in Indonesia. On the other hand, in some other countries this plant is classified as a noxious weed. As a harmful weed, A. cordifolia is reported to have the ability [...] Read more.

Anredera cordifolia (Tenore) Steenis is widely planted as an ornamental and medicinal plant in Indonesia. On the other hand, in some other countries this plant is classified as a noxious weed. As a harmful weed, A. cordifolia is reported to have the ability to smother all native vegetation, collapse canopies of tall trees, cultivate as a ground cover and disrupt native seedling development. There is no available information about the involvement of any allelochemicals from A. cordifolia related to these issues. The present study evaluated the allelopathic effect by isolating and identifying the allelopathic substance from A. cordifolia leaf extract. The allelopathic potency of A. cordifolia was determined by a series of bioassays of shoot and root growth on some selected test plants. Separation and purification of the active substances was achieved through several chromatography processes. Finally, the substances with allelopathic activity were identified through high-resolution electrospray ionization mass spectrometry (HRESIMS) analysis and determined by the specific rotation of compound, proton and carbon NMR spectroscopies. The results show that A. cordifolia possesses allelopathic properties which affect other plant species. The isolated compound from the plant material, 3-hydroxy-alpha-ionone, may contribute to the allelopathic effects of A. cordifolia. Full article

(This article belongs to the Special Issue Plant Phytochemicals on Crop Protection and Biotechnology)

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10 pages, 1993 KiB

Open AccessArticle

An Exploration of the Roles of Ferric Iron Chelation-Strategy Components in the Leaves and Roots of Maize Plants

by Georgios Saridis, Styliani N. Chorianopoulou, Yannis E. Ventouris, Petros P. Sigalas and Dimitris L. Bouranis

Plants 2019, 8(5), 133; https://doi.org/10.3390/plants8050133 - 18 May 2019

Cited by 7 | Viewed by 3149

Abstract

Plants have developed sophisticated mechanisms for acquiring iron from the soil. In the graminaceous species, a chelation strategy is in charge, in order to take up ferric iron from the rhizosphere. The ferric iron chelation-strategy components may also be present in the aerial [...] Read more.

Plants have developed sophisticated mechanisms for acquiring iron from the soil. In the graminaceous species, a chelation strategy is in charge, in order to take up ferric iron from the rhizosphere. The ferric iron chelation-strategy components may also be present in the aerial plant parts. The aim of this work was to search for possible roles of those components in maize leaves. To this end, the expression patterns of ferric iron chelation-strategy components were monitored in the leaves and roots of mycorrhizal and non-mycorrhizal sulfur-deprived maize plants, both before and after sulfate supply. The two levels of sulfur supply were chosen due to the strong impact of this nutrient on iron homeostasis, whilst mycorrhizal symbiosis was chosen as a treatment that forces the plant to optimize its photosynthetic efficiency, in order to feed the fungus. The results, in combination with the findings of our previous works, suggest a role for the aforementioned components in ferric chelation and/or unloading from the xylem vessels to the aerial plant parts. It is proposed that the gene expression of the DMA exporter ZmTOM1 can be used as an early indicator for the establishment of a mycorrhizal symbiotic relationship in maize. Full article

(This article belongs to the Special Issue Advances in Plant Sulfur Research)

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12 pages, 3673 KiB

Open AccessArticle

Lipophilic Metabolites and Anatomical Acclimatization of Cleome amblyocarpa in the Drought and Extra-Water Areas of the Arid Desert of UAE

by Sameh S.M. Soliman, Mohamed Abouleish, Maged M.M. Abou-Hashem, Alshaimaa M. Hamoda and Ali A. El-Keblawy

Plants 2019, 8(5), 132; https://doi.org/10.3390/plants8050132 - 16 May 2019

Cited by 10 | Viewed by 4418

Abstract

Plants adapt to different environmental conditions by developing structural and metabolic mechanisms. In this study, anatomical features and lipophilic metabolites were investigated in Cleome amblyocarpa Barr. & Murb., Cleomaceae plants growing in the arid desert of United Arab Emirates (UAE) in either low-water [...] Read more.

Plants adapt to different environmental conditions by developing structural and metabolic mechanisms. In this study, anatomical features and lipophilic metabolites were investigated in Cleome amblyocarpa Barr. & Murb., Cleomaceae plants growing in the arid desert of United Arab Emirates (UAE) in either low-water or extra-water areas, which were caused by the surrounding road run-off. The plant showed the presence of shaggy-like trichomes. The plant also developed special mechanisms to ensure its survival via release of lipophilic metabolites. The lipophilic metabolites, stained red with Sudan III, were apparently released by glandular trichomes and idioblasts of the shoot and roots, respectively. The identified lipophilic metabolites included those required for drought tolerance, protection against pathogens invasion, and detoxification. Plants growing in the low-water area caused an increase in the production of lipophilic metabolites—in particular, hydrocarbons and terpenoids. The lipophilic metabolites are known to provide the plant with unique waxy surfaces that reduce water loss and avoid penetration by pathogens. The release of lipid metabolites and the presence of shaggy-like trichomes represented unique features of the species that have never been reported. The provided chemical ecology information can be extended for several plant-related applications, particularly including drought tolerance. Full article

(This article belongs to the Special Issue Adaptation of Plants to Environmental Changes: Light and Temperature in Plant Development)

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12 pages, 592 KiB

Open AccessArticle

Effect of Dwarfing Gene Ddw1 on Height and Agronomic Traits in Spring Triticale in Greenhouse and Field Experiments in a Non-Black Earth Region of Russia

by Pavel Kroupin, Anastasiya Chernook, Gennady Karlov, Alexander Soloviev and Mikhail Divashuk

Plants 2019, 8(5), 131; https://doi.org/10.3390/plants8050131 - 16 May 2019

Cited by 6 | Viewed by 3069

Abstract

Triticale is a relatively new crop which still possesses serious drawbacks that can be significantly improved by breeding. The dwarfing genes proved to be very useful in the development of new lodging resistant and productive cultivars of winter triticale. The aim of our [...] Read more.

Triticale is a relatively new crop which still possesses serious drawbacks that can be significantly improved by breeding. The dwarfing genes proved to be very useful in the development of new lodging resistant and productive cultivars of winter triticale. The aim of our research was to assess the effect of the Ddw1 dwarfing gene from rye on the agronomic valuable traits in spring triticale. The Ddw1 effect was studied in the greenhouse experiment in segregating the F_2:3 population and in the field of F_3:4 and F_4:5 families derived from crossing winter triticale ‘Hongor’ (Ddw1Ddw1) and spring triticale ‘Dublet’ (ddw1ddw1). As a result, in all three generations, a strong decrease in plant height was demonstrated that was accompanied by a decrease in grain weight per spike and 1000-grain weight. In field experiments, a decrease in spike length and increase in spike density and delay in flowering and heading were observed. As a result of decrease in culm vegetative weight due to Ddw1, the harvest index measured in F_4:5 increased. The spike fertility and number of grains were not affected by Ddw1. The comparison of Ddw1 in rye, winter, and spring triticale, and the possible role of Ddw1 in improving spring triticale are discussed. Full article

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13 pages, 1686 KiB

Open AccessArticle

Interspaced Repeat Sequences Confer the Regulatory Functions of AtXTH10, Important for Root Growth in Arabidopsis

by Jun Cao, Yueqing Lv and Xiang Li

Plants 2019, 8(5), 130; https://doi.org/10.3390/plants8050130 - 16 May 2019

Cited by 5 | Viewed by 2614

Abstract

An interspaced repeat sequence (IRS) is a unique sequence similar to prokaryotic CRISPR in structure. In this study, 1343 IRSs were identified in the Arabidopsis genome. Functional annotation of the IRS-related genes showed that they were associated with various growth and development processes. [...] Read more.

An interspaced repeat sequence (IRS) is a unique sequence similar to prokaryotic CRISPR in structure. In this study, 1343 IRSs were identified in the Arabidopsis genome. Functional annotation of the IRS-related genes showed that they were associated with various growth and development processes. More than 30% of the IRSs were located in promoter regions. Deletion of some IRSs affected promoter activity, suggesting their roles in the regulation of gene expression. Next, the function of the AtXTH10 gene was further analyzed, and the expression of this gene was regulated by IRSs in its promoter region. Transgenic and mutant plants analysis indicated that the AtXTH10 gene was associated with root development by affecting cell wall structure. Moreover, the expression profiles of some key genes involved in root development signaling pathways were also affected by AtXTH10. These results suggest that IRSs could be involved in regulating the expression of genes with important roles in plant development. Full article

(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)

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17 pages, 4514 KiB

Open AccessArticle

The Morphological Features and Biology of a Relict and Endangered Woody Plant Species: Chamaedaphne calyculata (L.) Moench (Ericaceae)

by Anna Źróbek-Sokolnik, Piotr Dynowski and Mieczysława Aldona Fenyk

Plants 2019, 8(5), 129; https://doi.org/10.3390/plants8050129 - 15 May 2019

Cited by 2 | Viewed by 2717

Abstract

Chamaedaphne calyculata (L.) Moench is a rare post-glacial relic, which reaches the south-western boundary of its European range in Poland. However, little is known about the morphology and biology of this species. In this study a biometric analysis of assimilating leaves and general [...] Read more.

Chamaedaphne calyculata (L.) Moench is a rare post-glacial relic, which reaches the south-western boundary of its European range in Poland. However, little is known about the morphology and biology of this species. In this study a biometric analysis of assimilating leaves and general morphological appearance was carried out; flowering, fruiting, and seed production in a natural site were described and the ability of seed germination was determined after varied seed storage time at 0–2, 2–4, 6–8, and 21–23 °C. A quite large intrapopulation variability was found as regards the features under analysis. The most varied features included the length of the petiole, followed by the leaf blade area, while the length to the width of the leaf blade was the least varied feature. C. calyculata flowered abundantly and about 50% developed flowers turned into fruits. On average there were 56 seeds per fruit with a predominance of mature seeds. The length of the seed storage time had a significant effect on all parameters of the germination process. The temperature at which the seeds were stored, apart from the time to maximum germination parameter, had a significant effect on other parameters of the germination process. Interactions between the seeds storage time and temperature factors were observed only for germination percentage, germination index, and germination index rate parameters. The ability of seeds to germinate, non-creation of the seed bank and other results of the research provide new information necessary for planning and carrying out conservation procedures (including active conservation in ex situ conditions). Full article

(This article belongs to the Section Plant Ecology)

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17 pages, 891 KiB

Open AccessReview

Mutation Breeding in Tomato: Advances, Applicability and Challenges

by Juhi Chaudhary, Alisha Alisha, Vacha Bhatt, Sonali Chandanshive, Nirbhay Kumar, Zahoor Mir, Ashwini Kumar, Satish K. Yadav, S. M. Shivaraj, Humira Sonah and Rupesh Deshmukh

Plants 2019, 8(5), 128; https://doi.org/10.3390/plants8050128 - 14 May 2019

Cited by 73 | Viewed by 16765

Abstract

Induced mutagenesis is one of the most effective strategies for trait improvement without altering the well-optimized genetic background of the cultivars. In this review, several currently accessible methods such as physical, chemical and insertional mutagenesis have been discussed concerning their efficient exploration for [...] Read more.

Induced mutagenesis is one of the most effective strategies for trait improvement without altering the well-optimized genetic background of the cultivars. In this review, several currently accessible methods such as physical, chemical and insertional mutagenesis have been discussed concerning their efficient exploration for the tomato crop improvement. Similarly, challenges for the adaptation of genome-editing, a newly developed technique providing an opportunity to induce precise mutation, have been addressed. Several efforts of genome-editing have been demonstrated in tomato and other crops, exploring its effectiveness and convenience for crop improvement. Descriptive data compiled here from such efforts will be helpful for the efficient exploration of technological advances. However, uncertainty about the regulation of genome-edited crops is still a significant concern, particularly when timely trait improvement in tomato cultivars is needed. In this regard, random approaches of induced mutagenesis are still promising if efficiently explored in breeding applications. Precise identification of casual mutation is a prerequisite for the molecular understanding of the trait development as well as its utilization for the breeding program. Recent advances in sequencing techniques provide an opportunity for the precise detection of mutagenesis-induced sequence variations at a large scale in the genome. Here, we reviewed several novel next-generation sequencing based mutation mapping approaches including Mutmap, MutChromeSeq, and whole-genome sequencing-based mapping which has enormous potential to accelerate the mutation breeding in tomato. The proper utilization of the existing well-characterized tomato mutant resources combined with novel mapping approaches would inevitably lead to rapid enhancement of tomato quality and yield. This article provides an overview of the principles and applications of mutagenesis approaches in tomato and discusses the current progress and challenges involved in tomato mutagenesis research. Full article

(This article belongs to the Special Issue Advances in Plant Mutagenesis Research)

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16 pages, 1912 KiB

Open AccessArticle

Non-cultivated Cotton Species (Gossypium spp.) Act as a Reservoir for Cotton Leaf Curl Begomoviruses and Associated Satellites

by Sara Shakir, Syed Shan-e-Ali Zaidi, Atiq-ur-Rehman, Muhammad Farooq, Imran Amin, Jodi Scheffler, Brian Scheffler, Muhammad Shah Nawaz-ul-Rehman and Shahid Mansoor

Plants 2019, 8(5), 127; https://doi.org/10.3390/plants8050127 - 14 May 2019

Cited by 6 | Viewed by 3142

Abstract

A collection of cultivated and non-cultivated species of cotton (Gossypium spp.) has been maintained for the last four decades in Multan, Pakistan. This geographical location has been observed as a hotspot for the evolution of begomoviruses and satellites associated with cotton leaf [...] Read more.

A collection of cultivated and non-cultivated species of cotton (Gossypium spp.) has been maintained for the last four decades in Multan, Pakistan. This geographical location has been observed as a hotspot for the evolution of begomoviruses and satellites associated with cotton leaf curl disease (CLCuD). Recent studies showed that begomoviruses responsible for the CLCuD epidemic in the 1990s, and that almost disappeared from the CLCuD complex in 2000s, have been observed again in CLCuD-infected cotton fields. To identify host species that acted as probable reservoirs for these viruses, we characterized begomoviruses and satellites in non-cultivated cotton species G. raimondii, G. thurberi and G. mustelinum and identified several species of CLCuD associated begomoviruses and satellites. Further, phylogenetic analysis indicated that the identified begomoviruses and beta/alphasatellites are closely related to the ones associated with the most recent CLCuD complex. qPCR indicated that the comparative level of virus significantly decreased in the presence of alphasatellites. Our results indicated that non-cultivated cotton species have been continuously challenged by diverse begomoviruses and associated satellites and act as reservoirs for CLCuD associated begomoviruses. These results provide novel insights into understanding the spread of begomoviruses and associated satellites in New World cotton species introduced into the Old World. Full article

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15 pages, 8888 KiB

Open AccessArticle

Common Bean (Phaseolus vulgaris L.) Accumulates Most S-Methylcysteine as Its γ-Glutamyl Dipeptide

by Elham Saboori-Robat, Jaya Joshi, Aga Pajak, Mahmood Solouki, Motahhareh Mohsenpour, Justin Renaud and Frédéric Marsolais

Plants 2019, 8(5), 126; https://doi.org/10.3390/plants8050126 - 14 May 2019

Cited by 7 | Viewed by 3427

Abstract

The common bean (Phaseolus vulgaris) constitutes an excellent source of vegetable dietary protein. However, there are sub-optimal levels of the essential amino acids, methionine and cysteine. On the other hand, P. vulgaris accumulates large amounts of the γ-glutamyl dipeptide of S [...] Read more.

The common bean (Phaseolus vulgaris) constitutes an excellent source of vegetable dietary protein. However, there are sub-optimal levels of the essential amino acids, methionine and cysteine. On the other hand, P. vulgaris accumulates large amounts of the γ-glutamyl dipeptide of S-methylcysteine, and lower levels of free S-methylcysteine and S-methylhomoglutathione. Past results suggest two distinct metabolite pools. Free S-methylcysteine levels are high at the beginning of seed development and decline at mid-maturation, while there is a biphasic accumulation of γ-glutamyl-S-methylcysteine, at early cotyledon and maturation stages. A possible model involves the formation of S-methylcysteine by cysteine synthase from O-acetylserine and methanethiol, whereas the majority of γ-glutamyl-S-methylcysteine may arise from S-methylhomoglutathione. Metabolite profiling during development and in genotypes differing in total S-methylcysteine accumulation showed that γ-glutamyl-S-methylcysteine accounts for most of the total S-methylcysteine in mature seed. Profiling of transcripts for candidate biosynthetic genes indicated that BSAS4;1 expression is correlated with both the developmental timing and levels of free S-methylcysteine accumulated, while homoglutathione synthetase (hGS) expression was correlated with the levels of γ-glutamyl-S-methylcysteine. Analysis of S-methylated phytochelatins by liquid chromatography and high resolution tandem mass spectrometry revealed only small amounts of homophytochelatin-2 with a single S-methylcysteine. The mitochondrial localization of phytochelatin synthase 2—predominant in seed, determined by confocal microscopy of a fusion with the yellow fluorescent protein—and its spatial separation from S-methylhomoglutathione may explain the lack of significant accumulation of S-methylated phytochelatins. Full article

(This article belongs to the Special Issue Advances in Plant Sulfur Research)

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11 pages, 1113 KiB

Open AccessArticle

Evernia Goes to School: Bioaccumulation of Heavy Metals and Photosynthetic Performance in Lichen Transplants Exposed Indoors and Outdoors in Public and Private Environments

by Luca Paoli, Zuzana Fačkovcová, Anna Guttová, Caterina Maccelli, Katarína Kresáňová and Stefano Loppi

Plants 2019, 8(5), 125; https://doi.org/10.3390/plants8050125 - 13 May 2019

Cited by 18 | Viewed by 3681

Abstract

Recently indoor air quality (IAQ) has become a key issue, especially in schools, where children spend most of the day. Only in a few cases IAQ was investigated using lichens as biomonitors. During autumn 2017, lichens (Evernia prunastri) were exposed for [...] Read more.

Recently indoor air quality (IAQ) has become a key issue, especially in schools, where children spend most of the day. Only in a few cases IAQ was investigated using lichens as biomonitors. During autumn 2017, lichens (Evernia prunastri) were exposed for two months indoors and outdoors in public (schools) and private (dwellings) environments, in both rural and urban areas of Slovakia. The bioaccumulation of selected elements and the physiological status of the samples were considered. The content of heavy metals increased in samples exposed outdoors for 11 out of 12 elements (Al, As, Cd, Cr, Cu, Fe, Pb, S, Sb, V and Zn, but not Ca) in the urban area and for 5 (As, Cd, Cu, Pb and Sb) in the rural area. Indoor concentrations were overall similar, both in rural and urban buildings, independently of the outdoor conditions. An indoor accumulation occurred only for Cd, Cu and Pb. An indoor origin was suggested for Cd, while for Cu and Pb, outdoor penetration (car traffic) is the likely cause of indoor values. Indoor exposed lichens maintained their vitality (as reflected by chlorophyll a fluorescence emission). This latter result further supports the use of lichen biomonitoring as a suitable method for assessing IAQ. Full article

(This article belongs to the Section Plant Ecology)

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26 pages, 2276 KiB

Open AccessArticle

DRB1, DRB2 and DRB4 Are Required for Appropriate Regulation of the microRNA399/PHOSPHATE2 Expression Module in Arabidopsis thaliana

by Joseph L. Pegler, Jackson M. J. Oultram, Christopher P. L. Grof and Andrew L. Eamens

Plants 2019, 8(5), 124; https://doi.org/10.3390/plants8050124 - 13 May 2019

Cited by 10 | Viewed by 4230

Abstract

Adequate phosphorous (P) is essential to plant cells to ensure normal plant growth and development. Therefore, plants employ elegant mechanisms to regulate P abundance across their developmentally distinct tissues. One such mechanism is PHOSPHATE2 (PHO2)-directed ubiquitin-mediated degradation of a cohort of phosphate (PO [...] Read more.

Adequate phosphorous (P) is essential to plant cells to ensure normal plant growth and development. Therefore, plants employ elegant mechanisms to regulate P abundance across their developmentally distinct tissues. One such mechanism is PHOSPHATE2 (PHO2)-directed ubiquitin-mediated degradation of a cohort of phosphate (PO₄) transporters. PHO2 is itself under tight regulation by the PO₄ responsive microRNA (miRNA), miR399. The DOUBLE-STRANDED RNA BINDING (DRB) proteins, DRB1, DRB2 and DRB4, have each been assigned a specific functional role in the Arabidopsis thaliana (Arabidopsis) miRNA pathway. Here, we assessed the requirement of DRB1, DRB2 and DRB4 to regulate the miR399/PHO2 expression module under PO₄ starvations conditions. Via the phenotypic and molecular assessment of the knockout mutant plant lines, drb1, drb2 and drb4, we show here that; (1) DRB1 and DRB2 are required to maintain P homeostasis in Arabidopsis shoot and root tissues; (2) DRB1 is the primary DRB required for miR399 production; (3) DRB2 and DRB4 play secondary roles in regulating miR399 production, and; (4) miR399 appears to direct expression regulation of the PHO2 transcript via both an mRNA cleavage and translational repression mode of RNA silencing. Together, the hierarchical contribution of DRB1, DRB2 and DRB4 demonstrated here to be required for the appropriate regulation of the miR399/PHO2 expression module identifies the extreme importance of P homeostasis maintenance in Arabidopsis to ensure that numerous vital cellular processes are maintained across Arabidopsis tissues under a changing cellular environment. Full article

(This article belongs to the Special Issue The Role of MicroRNAs in Plants)

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8 pages, 1197 KiB

Open AccessArticle

Consistent Differences in Field Leaf Water-Use Efficiency among Soybean Cultivars

by James Bunce

Plants 2019, 8(5), 123; https://doi.org/10.3390/plants8050123 - 10 May 2019

Cited by 3 | Viewed by 2838

Abstract

High intrinsic water-use efficiency (WUE_i), the ratio of leaf photosynthesis to stomatal conductance, may be a useful trait in adapting crops to water-limited environments. In soybean, cultivar differences in stomatal response to vapor pressure deficit have not consistently translated into differences [...] Read more.

High intrinsic water-use efficiency (WUE_i), the ratio of leaf photosynthesis to stomatal conductance, may be a useful trait in adapting crops to water-limited environments. In soybean, cultivar differences in stomatal response to vapor pressure deficit have not consistently translated into differences in WUE_i in the field. In this study, six cultivars of soybeans previously shown to differ in WUE_i in indoor experiments were grown in the field in Beltsville, Maryland, and tested for mid-day WUE_i on nine clear days during the mid-seasons of two years. Measurement dates were chosen for diverse temperatures, and air temperatures ranged from 21 to 34 °C on the different dates. Air saturation deficits for water vapor ranged from 0.9 to 2.2 kPa. Corrected carbon isotope delta values for ¹³C (CID) were determined on mature, upper canopy leaves harvested during early pod filling each year. WUE_i differed among cultivars in both years and the differences were consistent across measurement dates. Correlations between mean WUE_i and CID were not significant in either year. It is concluded that consistent cultivar differences in WUE_i exist in these soybean cultivars under field conditions, but that carbon isotope ratios may not be useful in identifying them because of cultivar differences in mesophyll conductance. Full article

(This article belongs to the Section Plant Physiology and Metabolism)

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12 pages, 2166 KiB

Open AccessEditor’s ChoiceReview

Ascorbic Acid and Ozone: Novel Perspectives to Explain an Elusive Relationship

by Erika Bellini and Mario C. De Tullio

Plants 2019, 8(5), 122; https://doi.org/10.3390/plants8050122 - 09 May 2019

Cited by 44 | Viewed by 4940

Abstract

A huge amount of studies highlighted the importance of high ascorbic acid (AA) content in ozone tolerance, yet the relationship between them appears more complex than a simple direct correlation. Sometimes the connection is clear, for example, two Arabidopsis mutants defective in the [...] Read more.

A huge amount of studies highlighted the importance of high ascorbic acid (AA) content in ozone tolerance, yet the relationship between them appears more complex than a simple direct correlation. Sometimes the connection is clear, for example, two Arabidopsis mutants defective in the main AA biosynthetic pathway (vtc mutants) were identified by means of their ozone sensitivity. However, some low-AA containing mutants are relatively tolerant, suggesting that AA location/availability could be more relevant than total content. A clear distinction should also be made between ozone tolerance obtained when AA content is increased by experimental supplementation (exogenous AA), and the physiological role of plant-synthesized AA (endogenous AA), whose amount is apparently subjected to tight regulation. Recent findings about the role of AA in signal transduction and epigenetic regulation of gene expression open new routes to further research. Full article

(This article belongs to the Special Issue Ozone Tolerance Mechanisms)

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18 pages, 3438 KiB

Open AccessArticle

Assessing Impacts of Climate Change on Phenology and Quality Traits of Vitis vinifera L.: The Contribution of Local Knowledge

by Rita Biasi, Elena Brunori, Carlotta Ferrara and Luca Salvati

Plants 2019, 8(5), 121; https://doi.org/10.3390/plants8050121 - 09 May 2019

Cited by 44 | Viewed by 5108

Abstract

Developing adaptation strategies in Vitis vinifera, a crop sensitive to climate change, is crucial for resilience of traditional viticultural systems, especially in climate-vulnerable areas like the Mediterranean basin. A progressive warming is demonstrated to alter the geographical distribution of grapevine, reducing land [...] Read more.

Developing adaptation strategies in Vitis vinifera, a crop sensitive to climate change, is crucial for resilience of traditional viticultural systems, especially in climate-vulnerable areas like the Mediterranean basin. A progressive warming is demonstrated to alter the geographical distribution of grapevine, reducing land capability for typical grapes and vine productions in most Southern European districts traditionally specialized in tree crops. Grapevine growth and reproduction under climate change require a continuous monitoring to adapt agronomic practices and strategies to global change. The present study illustrates an empirical approach grounded on a set of bio-physical indicators assessing the genotype-related response to climate variation. This approach was tested in Umbria, central Italy, to verify the response of some major international and local grapevine varieties to climate variation during a relatively long time interval (1995–2015). Long-term data for ripening time and berry quality collected in the study area were correlated to representative bioclimatic indices including Winkler, Huglin, and Cool night indicators. Results of this study highlighted the increase of air temperature (reflecting the inherent growth in thermal availability for maturation) and the alteration of precipitation patterns toward more intense precipitation. Climate variability exerted distinctive impacts on grapevine phenology depending on the related genotype. Empirical findings underline the usefulness of a permanent field monitoring of the relationship between selected climate variables and grape ripening with the aim to develop adaptive viticultural practices at farm’s scale. Full article

(This article belongs to the Special Issue Adapting Crops to Climate Change)

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15 pages, 1129 KiB

Open AccessArticle

Pectin-Rich Amendment Enhances Soybean Growth Promotion and Nodulation Mediated by Bacillus Velezensis Strains

by Mohammad K. Hassan, John A. McInroy, Jarrod Jones, Deepak Shantharaj, Mark R. Liles and Joseph W. Kloepper

Plants 2019, 8(5), 120; https://doi.org/10.3390/plants8050120 - 09 May 2019

Cited by 29 | Viewed by 4865

Abstract

Plant growth-promoting rhizobacteria (PGPR) are increasingly used in crops worldwide. While selected PGPR strains can reproducibly promote plant growth under controlled greenhouse conditions, their efficacy in the field is often more variable. Our overall aim was to determine if pectin or orange peel [...] Read more.

Plant growth-promoting rhizobacteria (PGPR) are increasingly used in crops worldwide. While selected PGPR strains can reproducibly promote plant growth under controlled greenhouse conditions, their efficacy in the field is often more variable. Our overall aim was to determine if pectin or orange peel (OP) amendments to Bacillus velezensis (Bv) PGPR strains could increase soybean growth and nodulation by Bradyrhizobium japonicum in greenhouse and field experiments to reduce variability. The treatments included untreated soybean seeds planted in field soil that contained Bv PGPR strains and non-inoculated controls with and without 0.1% (w/v) pectin or (1 or 10 mg/200 μL) orange peel (OP) amendment. In greenhouse and field tests, 35 and 55 days after planting (DAP), the plants were removed from pots, washed, and analyzed for treatment effects. In greenhouse trials, the rhizobial inoculant was not added with Bv strains and pectin or OP amendment, but in the field trial, a commercial B. japonicum inoculant was used with Bv strains and pectin amendment. In the greenhouse tests, soybean seeds inoculated with Bv AP193 and pectin had significantly increased soybean shoot length, dry weight, and nodulation by indigenous Bradyrhizobium compared to AP193 without pectin. In the field trial, pectin with Bv AP193 significantly increased the shoot length, dry weight, and nodulation of a commercial Bradyrhizobium japonicum compared to Bv AP193 without pectin. In greenhouse tests, OP amendment with AP193 at 10 mg significantly increased the dry weight of shoots and roots compared to AP193 without OP amendment. The results demonstrate that pectin-rich amendments can enhance Bv-mediated soybean growth promotion and nodulation by indigenous and inoculated B. japonicum. Full article

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13 pages, 1104 KiB

Open AccessEditor’s ChoiceArticle

Effect of Phosphorus Fertilization on the Growth, Photosynthesis, Nitrogen Fixation, Mineral Accumulation, Seed Yield, and Seed Quality of a Soybean Low-Phytate Line

by Nisar Ahmad Taliman, Qin Dong, Kohei Echigo, Victor Raboy and Hirofumi Saneoka

Plants 2019, 8(5), 119; https://doi.org/10.3390/plants8050119 - 08 May 2019

Cited by 71 | Viewed by 8071

Abstract

Crop seed phosphorus (P) is primarily stored in the form of phytate, which is generally indigestible by monogastric animals. Low-phytate soybean lines have been developed to solve various problems related to seed phytate. There is little information available on the effects of P [...] Read more.

Crop seed phosphorus (P) is primarily stored in the form of phytate, which is generally indigestible by monogastric animals. Low-phytate soybean lines have been developed to solve various problems related to seed phytate. There is little information available on the effects of P fertilization on productivity, physiological characteristics, and seed yield and quality in low-phytate soybeans. To address this knowledge gap, studies were conducted with a low-phytate line and two normal-phytate cultivars from western Japan when grown under high- and low-P fertilization. The whole plant dry weight, leaf photosynthesis, dinitrogen fixation, and nodule dry weight at the flowering stage were higher in the higher P application level, but were not different between the low-phytate line and normal-phytate cultivars. As expected, seed yield was higher in the higher level of P application for all lines. Notably, it was higher in the low-phytate line as compared with the normal-phytate cultivars at both levels of fertilizer P. The total P concentration in the seeds of the low-phytate line was the same as that of the normal-phytate cultivars, but the phytate P concentration in the low-phytate line was about 50% less than that of the normal-phytate cultivars. As a result the molar ratio of phytic acid to Zn, Fe, Mn, and Cu in seed were also significantly lower in the low-phytate line. From these results, it can be concluded that growth after germination, leaf photosynthesis, nitrogen fixation, yield and seed quality were not less in the low-phytate soybean line as compared with two unrelated normal-phytate cultivars currently grown in Japan, and that low-phytate soybeans may improve the bioavailability of microelements. Full article

(This article belongs to the Special Issue Phytic Acid and Mineral Biofortification Strategies: From Plant Science to Breeding and Biotechnological Approaches)

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19 pages, 2448 KiB

Open AccessArticle

Determinants of Shoot Biomass Production in Mulberry: Combined Selection with Leaf Morphological and Physiological Traits

by Xu Cao, Qiudi Shen, Chunqiong Shang, Honglei Yang, Li Liu and Jialing Cheng

Plants 2019, 8(5), 118; https://doi.org/10.3390/plants8050118 - 06 May 2019

Cited by 12 | Viewed by 4053

Abstract

Physiological and morphological traits have a considerable impact on the biomass production of fast-growing trees. To compare cultivar difference in shoot biomass and investigate its relationships with leaf functional traits in mulberry, agronomic traits and 20 physiological and morphological attributes of 3-year-old mulberry [...] Read more.

Physiological and morphological traits have a considerable impact on the biomass production of fast-growing trees. To compare cultivar difference in shoot biomass and investigate its relationships with leaf functional traits in mulberry, agronomic traits and 20 physiological and morphological attributes of 3-year-old mulberry trees from eight cultivars growing in a common garden were analyzed. The cultivars Xiang7920, Yu711, and Yunsang2 had higher shoot fresh biomass (SFB), which was closely associated with their rapid leaf expansion rate, large leaf area, and high stable carbon isotope composition (δ¹³C). Conversely, the cultivars 7307, Husang32, Wupu, Yunguo1, and Liaolu11 were less productive, and this was primarily the result of slower leaf expansion and smaller leaf size. Growth performance was negatively correlated with leaf δ¹³C and positively correlated with the total nitrogen concentration, indicating that a compromise exists in mulberry between water use efficiency (WUE) (low δ¹³C) and high nitrogen consumption for rapid growth. Several morphological traits, including the maximum leaf area (LA_max), leaf width and length, petiole width and length, leaf number per shoot, and final shoot height were correlated with SFB. The physiological traits that were also influential factors of shoot biomass were the leaf δ¹³C, the total nitrogen concentration, and the water content. Among the studied leaf traits, LA_max, leaf δ¹³C, and concentrations of chlorophyll a and b were identified as the most representative predictor variables for SFB, accounting for 73% of the variability in SFB. In conclusion, a combination of LA_max, leaf δ¹³C, and chlorophyll should be considered in selection programs for high-yield mulberry cultivars. Full article

(This article belongs to the Special Issue From Genes to Shape and Function: Leaf Morphogenesis at Play)

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16 pages, 2723 KiB

Open AccessArticle

Ethylene Response of Plum ACC Synthase 1 (ACS1) Promoter is Mediated through the Binding Site of Abscisic Acid Insensitive 5 (ABI5)

by Avi Sadka, Qiaoping Qin, Jianrong Feng, Macarena Farcuh, Lyudmila Shlizerman, Yunting Zhang, David Toubiana and Eduardo Blumwald

Plants 2019, 8(5), 117; https://doi.org/10.3390/plants8050117 - 02 May 2019

Cited by 15 | Viewed by 4137

Abstract

The enzyme 1-amino-cyclopropane-1-carboxylic acid synthase (ACS) participates in the ethylene biosynthesis pathways and it is tightly regulated transcriptionally and post-translationally. Notwithstanding its major role in climacteric fruit ripening, the transcriptional regulation of ACS during ripening is not fully understood. We studied fruit ripening [...] Read more.

The enzyme 1-amino-cyclopropane-1-carboxylic acid synthase (ACS) participates in the ethylene biosynthesis pathways and it is tightly regulated transcriptionally and post-translationally. Notwithstanding its major role in climacteric fruit ripening, the transcriptional regulation of ACS during ripening is not fully understood. We studied fruit ripening in two Japanese plum cultivars, the climacteric Santa Rosa (SR) and its non-climacteric bud sport mutant, Sweet Miriam (SM). As the two cultivars show considerable difference in ACS expression, they provide a good system for the study of the transcriptional regulation of the gene. To investigate the differential transcriptional regulation of ACS1 genes in the SR and SM, their promoter regions, which showed only minor sequence differences, were isolated and used to identify the binding of transcription factors interacting with specific ACS1 cis-acting elements. Three transcription factors (TFs), abscisic acid-insensitive 5 (ABI5), GLABRA 2 (GL2), and TCP2, showed specific binding to the ACS1 promoter. Synthetic DNA fragments containing multiple cis-acting elements of these TFs fused to β-glucuronidase (GUS), showed the ABI5 binding site mediated ethylene and abscisic acid (ABA) responses of the promoter. While TCP2 and GL2 showed constant and similar expression levels in SM and SR fruit during ripening, ABI5 expression in SM fruits was lower than in SR fruits during advanced fruit ripening states. Overall, the work demonstrates the complex transcriptional regulation of ACS1. Full article

(This article belongs to the Section Plant Molecular Biology)

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17 pages, 1597 KiB

Open AccessArticle

High-Throughput Genotype, Morphology, and Quality Traits Evaluation for the Assessment of Genetic Diversity of Wheat Landraces from Sicily

by Maria Carola Fiore, Francesco Mercati, Alfio Spina, Sebastiano Blangiforti, Gianfranco Venora, Matteo Dell’Acqua, Antonio Lupini, Giovanni Preiti, Michele Monti, Mario Enrico Pè and Francesco Sunseri

Plants 2019, 8(5), 116; https://doi.org/10.3390/plants8050116 - 30 Apr 2019

Cited by 30 | Viewed by 4322

Abstract

During the XX Century, the widespread use of modern wheat cultivars drastically reduced the cultivation of ancient landraces, which nowadays are confined to niche cultivation areas. Several durum wheat landraces adapted to the extreme environments of the Mediterranean region, are still being cultivated [...] Read more.

During the XX Century, the widespread use of modern wheat cultivars drastically reduced the cultivation of ancient landraces, which nowadays are confined to niche cultivation areas. Several durum wheat landraces adapted to the extreme environments of the Mediterranean region, are still being cultivated in Sicily, Italy. Detailed knowledge of the genetic diversity of this germplasm could lay the basis for their efficient management in breeding programs, for a wide-range range of traits. The aim of the present study was to characterize a collection of durum wheat landraces from Sicily, using single nucleotide polymorphisms (SNP) markers, together with agro-morphological, phenological and quality-related traits. Two modern cv. Simeto, Claudio, and the hexaploid landrace, Cuccitta, were used as outgroups. Cluster analysis and Principal Coordinates Analysis (PCoA) allowed us to identify four main clusters across the analyzed germplasm, among which a cluster included only historical and modern varieties. Likewise, structure analysis was able to distinguish the ancient varieties from the others, grouping the entries in seven cryptic genetic clusters. Furthermore, a Principal Component Analysis (PCA) was able to separate the modern testers from the ancient germplasm. This approach was useful to classify and evaluate Sicilian ancient wheat germplasm, supporting their safeguard and providing a genetic fingerprint that is necessary for avoiding commercial frauds to sustaining the economic profits of farmers resorting to landraces cultivation. Full article

(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)

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17 pages, 2983 KiB

Open AccessArticle

¹H-NMR Metabolite Fingerprinting Analysis Reveals a Disease Biomarker and a Field Treatment Response in Xylella fastidiosa subsp. pauca-Infected Olive Trees

by Chiara Roberta Girelli, Federica Angilè, Laura Del Coco, Danilo Migoni, Luigi Zampella, Simone Marcelletti, Nicola Cristella, Paolo Marangi, Marco Scortichini and Francesco Paolo Fanizzi

Plants 2019, 8(5), 115; https://doi.org/10.3390/plants8050115 - 29 Apr 2019

Cited by 19 | Viewed by 4531

Abstract

Xylella fastidiosa subsp. pauca is a xylem-limited bacterial phytopathogen currently found associated on many hectares with the “olive quick decline syndrome” in the Apulia region (Southern Italy), and the cultivars Ogliarola salentina and Cellina di Nardò result in being particularly sensitive to the [...] Read more.

Xylella fastidiosa subsp. pauca is a xylem-limited bacterial phytopathogen currently found associated on many hectares with the “olive quick decline syndrome” in the Apulia region (Southern Italy), and the cultivars Ogliarola salentina and Cellina di Nardò result in being particularly sensitive to the disease. In order to find compounds showing the capability of reducing the population cell density of the pathogen within the leaves, we tested, in some olive orchards naturally-infected by the bacterium, a zinc-copper-citric acid biocomplex, namely Dentamet®, by spraying it to the crown, once per month, during spring and summer. The occurrence of the pathogen in the four olive orchards chosen for the trial was molecularly assessed. A ¹H NMR metabolomic approach, in conjunction with a multivariate statistical analysis, was applied to investigate the metabolic pattern of both infected and treated adult olive cultivars, Ogliarola salentina and Cellina di Nardò trees, in two sampling periods, performed during the first year of the trial. For both cultivars and sampling periods, the orthogonal partial least squares discriminant analysis (OPLS-DA) gave good models of separation according to the treatment application. In both cultivars, some metabolites such as quinic acid, the aldehydic form of oleoeuropein, ligstroside and phenolic compounds, were consistently found as discriminative for the untreated olive trees in comparison with the Dentamet®-treated trees. Quinic acid, a precursor of lignin, was confirmed as a disease biomarker for the olive trees infected by X. fastidiosa subsp. pauca. When treated with Dentamet®, the two cultivars showed a distinct response. A consistent increase in malic acid was observed for the Ogliarola salentina trees, whereas in the Cellina di Nardò trees the treatments attenuate the metabolic response to the infection. To note that in Cellina di Nardò trees at the first sampling, an increase in γ-aminobutyric acid (GABA) was observed. This study highlights how the infection incited by X. fastidiosa subsp. pauca strongly modifies the overall metabolism of olive trees, and how a zinc-copper-citric acid biocomplex can induce an early re-programming of the metabolic pathways in the infected trees. Full article

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12 pages, 2643 KiB

Open AccessEditor’s ChoiceArticle

Mutation of Inositol 1,3,4-trisphosphate 5/6-kinase6 Impairs Plant Growth and Phytic Acid Synthesis in Rice

by Meng Jiang, Yang Liu, Yanhua Liu, Yuanyuan Tan, Jianzhong Huang and Qingyao Shu

Plants 2019, 8(5), 114; https://doi.org/10.3390/plants8050114 - 29 Apr 2019

Cited by 50 | Viewed by 5035

Abstract

Inositol 1,3,4-trisphosphate 5/6-kinase (ITPK) is encoded by six genes in rice (OsITPK1-6). A previous study had shown that nucleotide substitutions of OsITPK6 could significantly lower the phytic acid content in rice grains. In the present study, the possibility of establishing a [...] Read more.

Inositol 1,3,4-trisphosphate 5/6-kinase (ITPK) is encoded by six genes in rice (OsITPK1-6). A previous study had shown that nucleotide substitutions of OsITPK6 could significantly lower the phytic acid content in rice grains. In the present study, the possibility of establishing a genome editing-based method for breeding low-phytic acid cultivars in rice was explored, in conjunction with the functional determination of OsITPK6. Four OsITPK6 mutant lines were generated by targeted mutagenesis of the gene’s first exon using the CRISPR/Cas9 method, one (ositpk6_1) with a 6-bp in-frame deletion, and other three with frameshift mutations (ositpk6_2, _3, and _4). The frameshift mutations severely impaired plant growth and reproduction, while the effect of ositpk6_1 was relatively limited. The mutant lines ositpk6_1 and _2 had significantly lower levels (−10.1% and −32.1%) of phytic acid and higher levels (4.12- and 5.18-fold) of inorganic phosphorus compared with the wild-type (WT) line. The line ositpk6_1 also showed less tolerance to osmotic stresses. Our research demonstrates that mutations of OsITPK6, while effectively reducing phytic acid biosynthesis in rice grain, could significantly impair plant growth and reproduction. Full article

(This article belongs to the Special Issue Phytic Acid and Mineral Biofortification Strategies: From Plant Science to Breeding and Biotechnological Approaches)

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10 pages, 910 KiB

Open AccessArticle

Selenium in Germinated Chickpea (Cicer arietinum L.) Increases the Stability of Its Oil Fraction

by Daniela Guardado-Félix, Sergio O. Serna-Saldivar, Janet A. Gutiérrez-Uribe and Cristina Chuck-Hernández

Plants 2019, 8(5), 113; https://doi.org/10.3390/plants8050113 - 27 Apr 2019

Cited by 11 | Viewed by 3398

Abstract

Selenium is an essential mineral in human nutrition. In order to assess its effect on the stability of chickpea oil, seeds were germinated and tested with different amounts of sodium selenite (0.0, 0.5, 1.0 and 2.0 mg/100g seeds) for four days. Oil was [...] Read more.

Selenium is an essential mineral in human nutrition. In order to assess its effect on the stability of chickpea oil, seeds were germinated and tested with different amounts of sodium selenite (0.0, 0.5, 1.0 and 2.0 mg/100g seeds) for four days. Oil was extracted from sprouted chickpea and its physical properties, fatty acid profile (FAME), oxidative stability index (OSI), lipase and lipoxygenase (LOX) activities, cellular antioxidant activity (CAA), and phenolics and carotenoids were assessed and compared to chickpea seed oil. The amount of chickpea oil and its acid value (AV) increased during germination. The OSI increased by 28%, 46% and 14% for 0.5, 1.0 and 2.0 mg/100g compared with non-selenium treated sprouts. Phenolics increased up to 36% and carotenoids reduced by half in germinated sprouts with and without selenium compared to seeds. Carotenoids increased by 16% in sprouts treated with 1.0 mg/100 g selenium compared to their counterparts without selenium. FAME was not affected by treatments but samples with the highest selenium concentration increased lipase activity by 19% and decreased lipoxygenase activity by 55% compared with untreated sprouts. The CAA of oils increased by 43% to 66% in all germinated treatments compared with seeds. Results suggest that Se-enriched chickpea sprouts could represent an excellent source of oil with a high OSI and CAA, associated with a reduction in LOX activity and an increase in phenolics, respectively. Full article

(This article belongs to the Special Issue Selenium Metabolism and Accumulation in Plants)

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15 pages, 1189 KiB

Open AccessReview

Gene Regulation Mediated by microRNA-Triggered Secondary Small RNAs in Plants

by Felipe Fenselau de Felippes

Plants 2019, 8(5), 112; https://doi.org/10.3390/plants8050112 - 26 Apr 2019

Cited by 21 | Viewed by 5876

Abstract

In plants, proper development and response to abiotic and biotic stimuli requires an orchestrated regulation of gene expression. Small RNAs (sRNAs) are key molecules involved in this process, leading to downregulation of their target genes. Two main classes of sRNAs exist, the small [...] Read more.

In plants, proper development and response to abiotic and biotic stimuli requires an orchestrated regulation of gene expression. Small RNAs (sRNAs) are key molecules involved in this process, leading to downregulation of their target genes. Two main classes of sRNAs exist, the small interfering RNAs (siRNAs) and microRNAs (miRNAs). The role of the latter class in plant development and physiology is well known, with many examples of how miRNAs directly impact the expression of genes in cells where they are produced, with dramatic consequences to the life of the plant. However, there is an aspect of miRNA biology that is still poorly understood. In some cases, miRNA targeting can lead to the production of secondary siRNAs from its target. These siRNAs, which display a characteristic phased production pattern, can act in cis, reinforcing the initial silencing signal set by the triggering miRNA, or in trans, affecting genes that are unrelated to the initial target. In this review, the mechanisms and implications of this process in the gene regulation mediated by miRNAs will be discussed. This work will also explore techniques for gene silencing in plants that are based on this unique pathway. Full article

(This article belongs to the Special Issue The Role of MicroRNAs in Plants)

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13 pages, 2966 KiB

Open AccessArticle

Natural Compounds That Modulate the Development of the Fungus Botrytis cinerea and Protect Solanum lycopersicum

by Esteban D. Rosero-Hernández, Javier Moraga, Isidro G. Collado and Fernando Echeverri

Plants 2019, 8(5), 111; https://doi.org/10.3390/plants8050111 - 26 Apr 2019

Cited by 14 | Viewed by 3397

Abstract

Botrytis cinerea is the causal agent of gray mold disease and is responsible for the loss of millions of dollars in crops in worldwide. Currently, this pathogen exhibits increasing resistance to conventional fungicides; therefore, better control methods and novel compounds with a more [...] Read more.

Botrytis cinerea is the causal agent of gray mold disease and is responsible for the loss of millions of dollars in crops in worldwide. Currently, this pathogen exhibits increasing resistance to conventional fungicides; therefore, better control methods and novel compounds with a more specific mechanism of action but without biocidal effects, are required. In this work, several natural compounds to control B. cinerea were analyzed in vitro. Detected effects were dependent on the stage of fungus development, and 3-phenyl-1-propanol displayed the most potent inhibition of in vitro germination, germ tube development, and sporulation. However, it had lower protection of leaves and postharvest fruit in plant infection. Isoeugenol and 1-phenylethanol exhibited lower inhibition of in vitro germination and sporulation, but at the highest concentrations, they inhibited germ tube elongation. Although the lowest rates of foliage infection were recorded using isoeugenol and 3-phenyl-1-propanol, 1-phenylethanol significantly decreased the disease in postharvest tomato fruit, with an efficacy like Mancozeb, but at 18 times lower micromolar concentration. All compounds resulted in high cell viability after spores were removed from the treatment solution exhibited high cell viability, suggesting a non-biocidal effect. The diversity of in vitro and in-plant effects seems to indicate a different mechanism of action. Full article

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15 pages, 1122 KiB

Open AccessCommunication

Preliminary Automated Determination of Edibility of Alternative Foods: Non-Targeted Screening for Toxins in Red Maple Leaf Concentrate

by Joshua M. Pearce, Maryam Khaksari and David Denkenberger

Plants 2019, 8(5), 110; https://doi.org/10.3390/plants8050110 - 26 Apr 2019

Cited by 16 | Viewed by 4986

Abstract

Alternative food supplies could maintain humanity despite sun-blocking global catastrophic risks (GCRs) that eliminate conventional agriculture. A promising alternative food is making leaf concentrate. However, the edibility of tree leaves is largely uncertain. To overcome this challenge, this study provides the methods for [...] Read more.

Alternative food supplies could maintain humanity despite sun-blocking global catastrophic risks (GCRs) that eliminate conventional agriculture. A promising alternative food is making leaf concentrate. However, the edibility of tree leaves is largely uncertain. To overcome this challenge, this study provides the methods for obtaining rapid toxics screening of common leaf concentrates. The investigation begins with a non-targeted approach using an ultra-high-resolution hybrid ion trap orbitrap mass spectrometer with electrospray ionization (ESI) coupled to an ultra-high pressure two-dimensional liquid chromatograph system on the most common North American leaf: the red maple. Identified chemicals from this non-targeted approach are then cross-referenced with the OpenFoodTox database to identify toxic chemicals. Identified toxins are then screened for formula validation and evaluated for risk as a food. The results after screening show that red maple leaf concentrate contains at least eight toxic chemicals, which upon analysis do not present substantial risks unless consumed in abundance. This indicates that red maple leaf is still a potential alternative food. The results are discussed in the context of expanding the analysis with open science and using leaf extract from other plants that are not traditionally used as foods to offset current global hunger challenges, and move to a more sustainable food system while also preparing for GCRs. Full article

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