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Plants, Volume 12, Issue 3 (February-1 2023) – 272 articles

Cover Story (view full-size image): In the Mediterranean, anthropogenic pressures have been moved to deeper off-shore areas to protect seagrass habitats. However, these conservation efforts have devoted little attention to the deepest P. oceanica meadows. The remote influence of off-shore nutrient discharges (urban wastes and aquaculture) was studied on deep P. oceanica meadows located at different distances up to 2.5 km away. At the physiological level, plant responses reflected the typical effects of anthropogenic discharges on seagrass meadows, mainly light and nutrient stress. Habitat degradation was observed even at distances of 2.5 km from the nearest pressure, suggesting that diffuse nutrient loads could have surpassed critical ecological thresholds and that safety distances could have been underestimated up to now. View this paper
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15 pages, 2086 KiB  
Article
Silicon Actuates Poplar Calli Tolerance after Longer Exposure to Antimony
by Eva Labancová, Zuzana Vivodová, Kristína Šípošová and Karin Kollárová
Plants 2023, 12(3), 689; https://doi.org/10.3390/plants12030689 - 03 Feb 2023
Cited by 2 | Viewed by 1225
Abstract
The presence of antimony (Sb) in high concentrations in the environment is recognized as an emerging problem worldwide. The toxicity of Sb in plant tissues is known; however, new methods of plant tolerance improvement must be addressed. Here, poplar callus (Populus alba [...] Read more.
The presence of antimony (Sb) in high concentrations in the environment is recognized as an emerging problem worldwide. The toxicity of Sb in plant tissues is known; however, new methods of plant tolerance improvement must be addressed. Here, poplar callus (Populus alba L. var. pyramidallis) exposed to Sb(III) in 0.2 mM concentration and/or to silicon (Si) in 5 mM concentration was cultivated in vitro to determine the impact of Sb/Si interaction in the tissue. The Sb and Si uptake, growth, the activity of superoxide dismutase (SOD), catalase (CAT), guaiacol-peroxidase (G-POX), nutrient concentrations, and the concentrations of photosynthetic pigments were investigated. To elucidate the action of Si during the Sb-induced stress, the impact of short and long cultivations was determined. Silicon decreased the accumulation of Sb in the calli, regardless of the length of the cultivation (by approx. 34%). Antimony lowered the callus biomass (by approx. 37%) and decreased the concentrations of photosynthetic pigments (up to 78.5%) and nutrients in the tissue (up to 21.7%). Silicon supported the plant tolerance to Sb via the modification of antioxidant enzyme activity, which resulted in higher biomass production (increased by approx. 35%) and a higher uptake of nutrients from the media (increased by approx. 10%). Silicon aided the development of Sb-tolerance over the longer cultivation period. These results are key in understanding the action of Si-developed tolerance against metalloids. Full article
(This article belongs to the Topic Effect of Heavy Metals on Plants)
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19 pages, 6665 KiB  
Article
Updated Organic Composition and Potential Therapeutic Properties of Different Varieties of Olive Leaves from Olea europaea
by Diana Melo Ferreira, Natália M. de Oliveira, Maria Helena Chéu, Diana Meireles, Lara Lopes, Maria Beatriz Oliveira and Jorge Machado
Plants 2023, 12(3), 688; https://doi.org/10.3390/plants12030688 - 03 Feb 2023
Cited by 5 | Viewed by 2170
Abstract
Olea europaea L. folium merits further exploration of the potential of its substrates for therapeutic supplements. Quantitative and qualitative analyses were conducted on samples of Madural, Verdeal, and Cobrançosa elementary leaves and leaf sprouts (mamões) collected in the region of Valpaços, [...] Read more.
Olea europaea L. folium merits further exploration of the potential of its substrates for therapeutic supplements. Quantitative and qualitative analyses were conducted on samples of Madural, Verdeal, and Cobrançosa elementary leaves and leaf sprouts (mamões) collected in the region of Valpaços, Portugal. Organic analysis assessed the moisture content, total carbohydrates, ash, protein, and fat contents, total phenolic content (TPC), vitamin E, and fatty acid (FA) profiles. Moisture content was determined through infrared hygrometry and TPC was determined by a spectrophotometric method. Concerning organic analysis, all leaf samples showed similar moisture content, though Cobrançosa’s leaf sprouts and Verdeal’s elementary leaves had slightly lower contents. Meanwhile, these cultivars also showed a higher TPC, α-tocopherol isomer, and fatty acid composition (FAC). FAC in all samples exhibited higher contents of PUFA and SFA than MUFA, with a predominance of linolenic and palmitic acids. Organic analyses of Cobrançosa’s leaf sprouts and Verdeal’s elementary leaf extracts allow for the prediction of adequate physiological properties regarding neuroinflammatory, neurobehavioral, metabolic, cardiovascular, osteo-degenerative, anti-ageing, pulmonary, and immunological defense disorders. These physiological changes observed in our preliminary in silico studies suggest an excellent nutraceutical, which should be borne in mind during severe pandemic situations. Full article
(This article belongs to the Special Issue Identification and Analysis of Bioactive Components from Plants)
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16 pages, 2630 KiB  
Article
Arbuscular Mycorrhizal Symbiosis Improves Ex Vitro Acclimatization of Sugarcane Plantlets (Saccharum spp.) under Drought Stress Conditions
by José Luis Spinoso-Castillo, María del Rosario Moreno-Hernández, Eucario Mancilla-Álvarez, Lino Sánchez-Segura, Ricardo Sánchez-Páez and Jericó Jabín Bello-Bello
Plants 2023, 12(3), 687; https://doi.org/10.3390/plants12030687 - 03 Feb 2023
Cited by 5 | Viewed by 2095
Abstract
The symbiotic associations between arbuscular mycorrhizal fungi (AMF) and plants can induce drought stress tolerance. In this study, we evaluated the effect of Glomus intraradices, a mycorrhizal fungus, on the ex vitro development and survival of sugarcane plantlets subjected to drought stress [...] Read more.
The symbiotic associations between arbuscular mycorrhizal fungi (AMF) and plants can induce drought stress tolerance. In this study, we evaluated the effect of Glomus intraradices, a mycorrhizal fungus, on the ex vitro development and survival of sugarcane plantlets subjected to drought stress during the acclimatization stage of micropropagation. In vitro obtained sugarcane plantlets (Saccharum spp. cv Mex 69–290) were inoculated with different doses of G. intraradices (0, 100, and 200 spores per plantlet) during greenhouse acclimatization. Sixty days after inoculation, plantlets were temporarily subjected to drought stress. We evaluated the survival rate, total chlorophyll, total protein, carotenoids, proline, betaine glycine, soluble phenolic content, and antioxidant capacity every 3 days for 12 days. Symbiotic interaction was characterized by microscopy. Our results showed that the survival rate of inoculated plants was higher in 45% than the treatment without mycorrhizae. Total chlorophyll, protein, proline, betaine glycine content, and antioxidant capacity were increased in AMF inoculated plants. The soluble phenolic content was higher in non-inoculated plants than the treatment with mycorrhizae during the drought stress period. Microscopy showed the symbiotic relationship between plant and AMF. The early inoculation of 100 spores of G. intraradices per sugarcane plantlet during the acclimatization stage could represent a preconditioning advantage before transplanting into the field and establishing basic seedbeds. Full article
(This article belongs to the Special Issue Sugarcane Biology and Genetic Breeding)
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11 pages, 1692 KiB  
Article
Differential Effect of Free-Air CO2 Enrichment (FACE) in Different Organs and Growth Stages of Two Cultivars of Durum Wheat
by Angie L. Gámez, Xue Han and Iker Aranjuelo
Plants 2023, 12(3), 686; https://doi.org/10.3390/plants12030686 - 03 Feb 2023
Cited by 2 | Viewed by 1271
Abstract
Wheat is a target crop within the food security context. The responses of wheat plants under elevated concentrations of CO2 (e[CO2]) have been previously studied; however, few of these studies have evaluated several organs at different phenological stages [...] Read more.
Wheat is a target crop within the food security context. The responses of wheat plants under elevated concentrations of CO2 (e[CO2]) have been previously studied; however, few of these studies have evaluated several organs at different phenological stages simultaneously under free-air CO2 enrichment (FACE) conditions. The main objective of this study was to evaluate the effect of e[CO2] in two cultivars of wheat (Triumph and Norin), analyzed at three phenological stages (elongation, anthesis, and maturation) and in different organs at each stage, under FACE conditions. Agronomic, biomass, physiological, and carbon (C) and nitrogen (N) dynamics were examined in both ambient CO2 (a[CO2]) fixed at 415 µmol mol−1 CO2 and e[CO2] at 550 µmol mol−1 CO2. We found minimal effect of e[CO2] compared to a[CO2] on agronomic and biomass parameters. Also, while exposure to 550 µmol mol−1 CO2 increased the photosynthetic rate of CO2 assimilation (An), the current study showed a diminishment in the maximum carboxylation (Vc,max) and maximum electron transport (Jmax) under e[CO2] conditions compared to a[CO2] at physiological level in both cultivars. However, even if no significant differences were detected between cultivars on photosynthetic machinery, differential responses between cultivars were detected in C and N dynamics at e[CO2]. Triumph showed starch accumulation in most organs during anthesis and maturation, but a decline in N content was observed. Contrastingly, in Norin, a decrease in starch content during the three stages and an increase in N content was observed. The amino acid content decreased in grain and shells at maturation in both cultivars, which might indicate a minimal translocation from source to sink organs. These results suggest a greater acclimation to e[CO2] enrichment in Triumph than Norin, because both the elongation stage and e[CO2] modified the source–sink relationship. According to the differences between cultivars, future studies should be performed to test genetic variation under FACE technology and explore the potential of cultivars to cope with projected climate scenarios. Full article
(This article belongs to the Special Issue Plant Responses to Future Climate Scenarios)
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17 pages, 3224 KiB  
Article
Bio-Intensive Tactics for the Management of Invasive Fall Armyworm for Organic Maize Production
by Manikyanahalli Chandrashekara Keerthi, Sachin Suresh Suroshe, Sagar Doddachowdappa, Kadanakuppe Thammayya Shivakumara, Hosapura Shekhararaju Mahesha, Virendra Singh Rana, Ankita Gupta, Ajith Murukesan, Ryan Casini, Hosam O. Elansary and Najam Akhtar Shakil
Plants 2023, 12(3), 685; https://doi.org/10.3390/plants12030685 - 03 Feb 2023
Cited by 4 | Viewed by 2997
Abstract
Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an invasive pest native to the American continent. The present study focused on bio-intensive tactics like intercropping, using natural enemies, botanical insecticides and biopesticides for managing S. frugiperda for the organic production of maize in Indian [...] Read more.
Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an invasive pest native to the American continent. The present study focused on bio-intensive tactics like intercropping, using natural enemies, botanical insecticides and biopesticides for managing S. frugiperda for the organic production of maize in Indian conditions. A total of eight different parasitoids attacking the different stages of S. frugiperda viz., eggs and larvae were found in the study area. The total parasitism rate due to all the parasitoids ranged from 28.37 to 42.44%. The egg-larval parasitoid, Chelonus formosanus Sonan (Hymenoptera: Braconidae) was the dominant parasitoid (12.55%), followed by Chelonus nr. blackburni (Hymenoptera: Braconidae) (10.98%) and Coccygydium sp. (4.85%). About 36.58 percent of the egg masses collected was parasitized by egg parasitoids, among which Telenomus remus (Nixon) (Hymenoptera: Scelionidae) was the dominant parasitoid. The botanicals insecticides such as citronella and annona extract were most effective, resulting in 100% mortality of FAW larvae (168 h after treatment). The essential oil of garlic (100%) was found highly effective in inhibiting egg hatching, followed by geraniol (90.76%). The maize intercropped with lady’s finger (okra) recorded significantly the lowest pest infestation and recorded higher grain yield (6.17 q/ha) than other intercropping systems and control (5.10 q/ha). The overall bioefficacy of commercial biopesticides against the larvae of S. frugiperda was in the following order azadirachtin > Metarhizium anisopliae (Metch.) Sorokin (Hypocreales: Clavicipitaceae) > Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) at 168 h after treatment. Full article
(This article belongs to the Special Issue Novel Biocontrol Tools and Resources for Plant Protection)
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13 pages, 641 KiB  
Article
The Effect of Wool Mulch on Plant Development in the Context of the Physical and Biological Conditions in Soil
by Katalin Juhos, Enikő Papdi, Flórián Kovács, Vasileios P. Vasileiadis and Andrea Veres
Plants 2023, 12(3), 684; https://doi.org/10.3390/plants12030684 - 03 Feb 2023
Cited by 2 | Viewed by 2198
Abstract
Mulching techniques can comprise a solution that better utilizes precipitation and irrigation water in such a manner that mitigates soil degradation and drought damage; however, there are still gaps in the literature with regard to the effect of the use of mulch materials [...] Read more.
Mulching techniques can comprise a solution that better utilizes precipitation and irrigation water in such a manner that mitigates soil degradation and drought damage; however, there are still gaps in the literature with regard to the effect of the use of mulch materials on the development of plant–soil–microbe interactions. Waste fibers, as alternative biodegradable mulch materials, are becoming increasingly prominent. The effect of wool mulch (WM) on water use efficiency, with regard to pepper seedlings, was investigated in different soil types (sand, clay loam, peat) in a pot experiment. Two semi-field experiments were also set up to investigate the effect of WM–plant interactions on sweet pepper yields, as compared with agro textiles and straw mulches. Soil parameters (moisture, temperature, DHA, β-glucosidase enzymes, permanganate-oxidizable carbon) were measured during the growing season. The effect of WM on yield and biomass was more significant with the less frequent irrigation and the greater water-holding capacity of soils. Microbiological activity was significantly higher in the presence of plants, and because of the water retention of WM, the metabolic products of roots and the more balanced soil temperature were caused by plants. In the sandy soil, the straw mulch had a significantly better effect on microbiological parameters and yields than the agro textiles and WM. In soils with a higher water capacity, WM is a sustainable practice for improving the biological parameters and water use efficiency of soil. The effect of WM on yields cannot solely be explained by the water retention of the mulch; indeed, the development of biological activity and plant–soil–microbe interactions in the soil are also contributing factors. Full article
(This article belongs to the Special Issue Advances in Plant-Soil-Microbe Interactions)
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60 pages, 29104 KiB  
Article
Taxonomic Advances from Fungal Flora Associated with Ferns and Fern-like Hosts in Northern Thailand
by Elaheh Seifollahi, Antonio Roberto Gomes de Farias, Ruvishika Shehali Jayawardena and Kevin D. Hyde
Plants 2023, 12(3), 683; https://doi.org/10.3390/plants12030683 - 03 Feb 2023
Cited by 2 | Viewed by 2003
Abstract
Ferns are one of the most significant plant groupings that comprise a substantial proportion of the plant flora due to the fact of their great diversity, especially in tropical areas. The biodiversity of fungi associated with ferns and fern-like hosts has also received [...] Read more.
Ferns are one of the most significant plant groupings that comprise a substantial proportion of the plant flora due to the fact of their great diversity, especially in tropical areas. The biodiversity of fungi associated with ferns and fern-like hosts has also received little attention in studies. Plant samples were collected from diseased and dead plants of ten fern or fern-like species from Chiang Rai in northern Thailand. Forty-one isolates were selected from the obtained isolates for molecular and morphological analysis, with a focus on pathogenic fungal genera and consideration of the diversity in host and geographical location. Twenty-six species belonging to seven genera (Colletotrichum, Curvularia, Diaporthe, Fusarium, Lasiodiplodia, Neopestalotiopsis, and Pestalotiopsis) in six families were identified. Thirty new hosts, eight new geographical hosts, and one new species, Colletotrichum polypodialium, are described. Nepestalotiopsis phangngaensis, N. pandancola, Diaporthe tectonendophytica, D. chiangraiensis, and D. delonicis were isolated for the first time from leaf spots. Additionally, new reservoirs and geographical locations for species previously isolated from leaf spots or whose pathogenicity was established were found. However, more studies are necessary to prove the pathogenicity of the fungi isolated from the leaf spots and to identify the fungi associated with other species of ferns. Full article
(This article belongs to the Special Issue The Research of Plant Fungal Disease)
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21 pages, 1656 KiB  
Article
Characterization of a Disease-Suppressive Isolate of Lysobacter enzymogenes with Broad Antagonistic Activity against Bacterial, Oomycetal and Fungal Pathogens in Different Crops
by Christian Drenker, Doris El Mazouar, Gerrit Bücker, Sonja Weißhaupt, Eveline Wienke, Eckhard Koch, Stefan Kunz, Annette Reineke, Yvonne Rondot and Ada Linkies
Plants 2023, 12(3), 682; https://doi.org/10.3390/plants12030682 - 03 Feb 2023
Cited by 5 | Viewed by 1619
Abstract
Although synthetic pesticides play a major role in plant protection, their application needs to be reduced because of their negative impact on the environment. This applies also to copper preparations, which are used in organic farming. For this reason, alternatives with less impact [...] Read more.
Although synthetic pesticides play a major role in plant protection, their application needs to be reduced because of their negative impact on the environment. This applies also to copper preparations, which are used in organic farming. For this reason, alternatives with less impact on the environment are urgently needed. In this context, we evaluated eight isolates of the genus Lysobacter (mainly Lysobacter enzymogenes) for their activity against plant pathogens. In vitro, the investigated Lysobacter isolates showed broad antagonistic activity against several phytopathogenic fungi, oomycetes and bacteria. Enzyme assays revealed diverse activities for the tested isolates. The most promising L. enzymogenes isolate (LEC) was used for further detailed analyses of its efficacy and effective working concentrations. The experiments included in vitro spore and sporangia germination tests and leaf disc assays as well as ad planta growth chamber trials against Alternaria solani and Phytophthora infestans on tomato plants, Pseudoperonospora cubensis on cucumbers and Venturia inaequalis on young potted apple trees. When applied on leaves, dilutions of a culture suspension of LEC had a concentration-dependent, protective effect against the tested pathogens. In all pathosystems tested, the effective concentrations were in the range of 2.5–5% and similarly efficacious to common plant protection agents containing copper hydroxide, wettable sulphur or fenhexamid. Thus, the isolate of L. enzymogenes identified in this study exhibits a broad activity against common plant pathogens and is therefore a promising candidate for the development of a microbial biocontrol agent. Full article
(This article belongs to the Special Issue Plant–Microbe Interactions for Sustainable Agriculture)
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23 pages, 2538 KiB  
Article
Effects of Co-Inoculating Saccharomyces spp. with Bradyrhizobium japonicum on Atmospheric Nitrogen Fixation in Soybeans (Glycine max (L.))
by Obey Kudakwashe Zveushe, Victor Resco de Dios, Hengxing Zhang, Fang Zeng, Siqin Liu, Songrong Shen, Qianlin Kang, Yazhen Zhang, Miao Huang, Ahmed Sarfaraz, Matina Prajapati, Lei Zhou, Wei Zhang, Ying Han and Faqin Dong
Plants 2023, 12(3), 681; https://doi.org/10.3390/plants12030681 - 03 Feb 2023
Cited by 13 | Viewed by 2522
Abstract
Crop production encounters challenges due to the dearth of nitrogen (N) and phosphorus (P), while excessive chemical fertilizer use causes environmental hazards. The use of N-fixing microbes and P-solubilizing microbes (PSMs) can be a sustainable strategy to overcome these problems. Here, we conducted [...] Read more.
Crop production encounters challenges due to the dearth of nitrogen (N) and phosphorus (P), while excessive chemical fertilizer use causes environmental hazards. The use of N-fixing microbes and P-solubilizing microbes (PSMs) can be a sustainable strategy to overcome these problems. Here, we conducted a greenhouse pot experiment following a completely randomized blocked design to elucidate the influence of co-inoculating N-fixing bacteria (Bradyrhizobium japonicum) and PSMs (Saccharomyces cerevisiae and Saccharomyces exiguus) on atmospheric N2-fixation, growth, and yield. The results indicate a significant influence of interaction on Indole-3-acetic acid production, P solubilization, seedling germination, and growth. It was also found that atmospheric N2-fixation, nodule number per plant, nodule dry weight, straw, and root dry weight per plant at different growth stages were significantly increased under dual inoculation treatments relative to single inoculation or no inoculation treatment. Increased seed yield and N and P accumulation were also noticed under co-inoculation treatments. Soil available N was highest under sole bacterial inoculation and lowest under the control treatment, while soil available P was highest under co-inoculation treatments and lowest under the control treatment. We demonstrated that the co-inoculation of N-fixing bacteria and PSMs enhances P bioavailability and atmospheric N2-fixation in soybeans leading to improved soil fertility, raising crop yields, and promoting sustainable agriculture. Full article
(This article belongs to the Special Issue Interactions between Plants and Soil Microorganisms)
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15 pages, 2525 KiB  
Article
QTL Analysis Reveals Conserved and Differential Genetic Regulation of Maize Lateral Angles above the Ear
by Yanbin Zhu, Bo Song, Yanling Guo, Baobao Wang, Changcheng Xu, Hongyu Zhu, Lizhu E, Jinsheng Lai, Weibin Song and Haiming Zhao
Plants 2023, 12(3), 680; https://doi.org/10.3390/plants12030680 - 03 Feb 2023
Viewed by 1700
Abstract
Improving the density tolerance and planting density has great importance for increasing maize production. The key to promoting high density planting is breeding maize with a compact canopy architecture, which is mainly influenced by the angles of the leaves and tassel branches above [...] Read more.
Improving the density tolerance and planting density has great importance for increasing maize production. The key to promoting high density planting is breeding maize with a compact canopy architecture, which is mainly influenced by the angles of the leaves and tassel branches above the ear. It is still unclear whether the leaf angles of different stem nodes and tassel branches are controlled by similar genetic regulatory mechanisms, which limits the ability to breed for density-tolerant maize. Here, we developed a population with 571 double haploid lines derived from inbred lines, PHBA6 and Chang7-2, showing significant differences in canopy architecture. Phenotypic and QTL analyses revealed that the genetic regulation mechanism was largely similar for closely adjacent leaves above the ears. In contrast, the regulation mechanisms specifying the angles of distant leaves and the angles of leaves vs. tassel branches are largely different. The liguless1 gene was identified as a candidate gene for QTLs co-regulating the angles of different leaves and the tassel branch, consistent with its known roles in regulating plant architecture. Our findings can be used to develop strategies for the improvement of leaf and tassel architecture through the introduction of trait-specific or pleiotropic genes, thus benefiting the breeding of maize with increased density tolerance in the future. Full article
(This article belongs to the Special Issue Functional Genomics and Molecular Breeding of Crops)
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12 pages, 3455 KiB  
Article
Pollination in Epidendrum densiflorum Hook. (Orchidaceae: Laeliinae): Fraudulent Trap-Flowers, Self-Incompatibility, and a Possible New Type of Mimicry
by Rodrigo Santtanna Silveira, Rodrigo Bustos Singer and Viviane Gianluppi Ferro
Plants 2023, 12(3), 679; https://doi.org/10.3390/plants12030679 - 03 Feb 2023
Cited by 1 | Viewed by 2348
Abstract
The pollination and the breeding system of Epidendrum densiflorum (Orchidaceae: Laeliinae) were studied through fieldwork and controlled pollinations in cultivated plants. Pollination is exclusively promoted by males of diurnal Lepidoptera: five species of Arctiinae and four of Ithomiinae were recorded as pollinators. These [...] Read more.
The pollination and the breeding system of Epidendrum densiflorum (Orchidaceae: Laeliinae) were studied through fieldwork and controlled pollinations in cultivated plants. Pollination is exclusively promoted by males of diurnal Lepidoptera: five species of Arctiinae and four of Ithomiinae were recorded as pollinators. These male insects are known to obtain alkaloids (through the nectar) in flowers of Asteraceae and Boraginaceae. However, the flowers of E. densiflorum are nectarless, despite presenting a cuniculus (a likely nectariferous cavity). Pollinators insert their proboscides into the flowers and remove or deposit the pollinaria while searching for nectar. The floral tube is very narrow, and insects struggle for up to 75 min to get rid of the flowers. Plants are pollinator-dependent and nearly fully self-incompatible. Pollinarium removal, pollination, and fruiting success (2.85%) were very low; facts that are consistent with the patterns globally observed in deceptive (rewardless) orchids. Nilsson’s male efficiency factor (0.245) was also low, indicating pollen loss in the system. Based on our field observations, we suggest that the fragrance of E. densiflorum likely mimics these plants that are normally used as a source of alkaloids by male Lepidoptera, a hypothesis that we intend to test in the future. Full article
(This article belongs to the Special Issue Floral Secretory Tissue: Nectaries and Osmophores)
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17 pages, 6921 KiB  
Article
ADH Gene Cloning and Identification of Flooding-Responsive Genes in Taxodium distichum (L.) Rich
by Rui Zhang, Lei Xuan, Longjie Ni, Ying Yang, Ya Zhang, Zhiquan Wang, Yunlong Yin and Jianfeng Hua
Plants 2023, 12(3), 678; https://doi.org/10.3390/plants12030678 - 03 Feb 2023
Cited by 2 | Viewed by 1665
Abstract
As a flooding-tolerant tree species, Taxodium distichum has been utilized in afforestation projects and proven to have important value in flooding areas. Alcohol dehydrogenase (ADH), which participates in ethanol fermentation, is essential for tolerance to the anaerobic conditions caused by flooding. In a [...] Read more.
As a flooding-tolerant tree species, Taxodium distichum has been utilized in afforestation projects and proven to have important value in flooding areas. Alcohol dehydrogenase (ADH), which participates in ethanol fermentation, is essential for tolerance to the anaerobic conditions caused by flooding. In a comprehensive analysis of the ADH gene family in T. distichum, TdADHs were cloned on the basis of whole-genome sequencing, and then bioinformatic analysis, subcellular localization, and gene expression level analysis under flooding were conducted. The results show that the putative protein sequences of 15 cloned genes contained seven TdADHs and eight TdADH-like genes (one Class III ADH included) that were divided into five clades. All the sequences had an ADH_N domain, and except for TdADH-likeE2, all the other genes had an ADH_zinc_N domain. Moreover, the TdADHs in clades A, B, C, and D had a similar motif composition. Additionally, the number of TdADH amino acids ranged from 277 to 403, with an average of 370.13. Subcellular localization showed that, except for TdADH-likeD3, which was not expressed in the nucleus, the other genes were predominantly expressed in both the nucleus and cytosol. TdADH-likeC2 was significantly upregulated in all three organs (roots, stems, and leaves), and TdADHA3 was also highly upregulated under 24 h flooding treatment; the two genes might play key roles in ethanol fermentation and flooding tolerance. These findings offer a comprehensive understanding of TdADHs and could provide a foundation for the molecular breeding of T. distichum and current research on the molecular mechanisms driving flooding tolerance. Full article
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20 pages, 13676 KiB  
Article
Gene Profiling of the Ascorbate Oxidase Family Genes under Osmotic and Cold Stress Reveals the Role of AnAO5 in Cold Adaptation in Ammopiptanthus nanus
by Ming Zhu, Qi Liu, Fuyu Liu, Lamei Zheng, Jie Bing, Yijun Zhou and Fei Gao
Plants 2023, 12(3), 677; https://doi.org/10.3390/plants12030677 - 03 Feb 2023
Cited by 6 | Viewed by 1482
Abstract
The uplift of the Qinghai Tibet Plateau has led to a drastic change in the climate in Central Asia, from warm and rainy, to dry and less rainfall. Ammopiptanthus nanus, a rare evergreen broad-leaved shrub distributed in the temperate desert region of [...] Read more.
The uplift of the Qinghai Tibet Plateau has led to a drastic change in the climate in Central Asia, from warm and rainy, to dry and less rainfall. Ammopiptanthus nanus, a rare evergreen broad-leaved shrub distributed in the temperate desert region of Central Asia, has survived the drastic climate change in Central Asia caused by the uplift of the Qinghai-Tibet Plateau. Ascorbate oxidase (AO) regulates the redox status of the apoplast by catalyzing the oxidation of ascorbate acid to dehydroascorbic acid, and plays a key role in the adaptation of plants to environmental changes. Analyzing the evolution, environmental response, and biological functions of the AO family of A. nanus is helpful for understanding how plant genome evolution responds to climate change in Central Asia. A total of 16 AOs were identified in A. nanus, all of which contained the ascorbate oxidase domain, most of which contained transmembrane domain, and many were predicted to be localized in the apoplast. Segmental duplication and tandem duplication are the main factors driving the gene amplification of the AO gene family in A. nanus. Gene expression analysis based on transcriptome data and fluorescence quantitative PCR, as well as enzyme activity measurements, showed that the expression levels of AO genes and total enzyme activity decreased under short-term osmotic stress and low-temperature stress, but the expression of some AO genes (AnAO5, AnAO13, and AnAO16) and total enzyme activity increased under 7 days of cold stress. AnAO5 and AnAO11 are targeted by miR4415. Further functional studies on AnAO5 showed that AnAO5 protein was localized in the apoplast. The expression of AnAO5 in yeast cells and the transient expression in tobacco enhanced the tolerance of yeast and tobacco to low-temperature stress, and the overexpression of AnAO5 enhanced the tolerance of Arabidopsis seedlings to cold stress. Our research provides important data for understanding the role of AOs in plant adaptation to environmental change. Full article
(This article belongs to the Special Issue Plant-Soil Interaction Response to Global Change)
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13 pages, 3499 KiB  
Article
Understanding the Active Mechanisms of Plant (Sesuvium portulacastrum L.) against Heavy Metal Toxicity
by Emad A. Alsherif, Mohammad Yaghoubi Khanghahi, Carmine Crecchio, Shereen Magdy Korany, Renato Lustosa Sobrinho and Hamada AbdElgawad
Plants 2023, 12(3), 676; https://doi.org/10.3390/plants12030676 - 03 Feb 2023
Cited by 8 | Viewed by 2002
Abstract
Through metabolic analysis, the present research seeks to reveal the defense mechanisms activated by a heavy metals-resistant plant, Sesuvium portulacastrum L. In this regard, shifting metabolisms in this plant were investigated in different heavy metals-contaminated experimental sites, which were 50, 100, 500, 1000, [...] Read more.
Through metabolic analysis, the present research seeks to reveal the defense mechanisms activated by a heavy metals-resistant plant, Sesuvium portulacastrum L. In this regard, shifting metabolisms in this plant were investigated in different heavy metals-contaminated experimental sites, which were 50, 100, 500, 1000, and 5000 m away from a man-fabricated sewage dumping lake, with a wide range of pollutant concentrations. Heavy metals contaminations in contaminated soil and their impact on mineral composition and microbial population were also investigated. The significant findings to emerge from this research were the modifications of nitrogen and carbon metabolisms in plant tissues to cope with heavy metal toxicity. Increased plant amylase enzymes activity in contaminated soils increased starch degradation to soluble sugars as a mechanism to mitigate stress impact. Furthermore, increased activity of sucrose phosphate synthase in contaminated plants led to more accumulation of sucrose. Moreover, no change in the content of sucrose hydrolyzing enzymes (vacuolar invertase and cytosolic invertase) in the contaminated sites can suggest the translocation of sucrose from shoot to root under stress. Similarly, although this study demonstrated a high level of malate in plants exposed to stress, caution must be applied in suggesting a strong link between organic acids and the activation of defense mechanisms in plants, since other key organic acids were not affected by stress. Therefore, activation of other defense mechanisms, especially antioxidant defense molecules including alpha and beta tocopherols, showed a greater role in protecting plants from heavy metals stress. Moreover, the increment in the content of some amino acids (e.g., glycine, alanine, glutamate, arginine, and ornithine) in plants under metal toxicity can be attributed to a high level of stress tolerance. Moreover, strategies in the excitation of the synthesis of the unsaturated fatty acids (oleic and palmitoleic) were involved in enhancing stress tolerance, which was unexpectedly associated with an increase in the accumulation of palmitic and stearic (saturated fatty acids). Taken together, it can be concluded that these multiple mechanisms were involved in the response to stress which may be cooperative and complementary with each other in inducing resistance to the plants. Full article
(This article belongs to the Special Issue Heavy Metal Damage and Tolerance in Plants)
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15 pages, 11385 KiB  
Article
LG5, a Novel Allele of EUI1, Regulates Grain Size and Flag Leaf Angle in Rice
by Zhen Li, Junrong Liu, Xingyu Wang, Jing Wang, Junhua Ye, Siliang Xu, Yuanyuan Zhang, Dongxiu Hu, Mengchen Zhang, Qun Xu, Shan Wang, Yaolong Yang, Xinghua Wei, Yue Feng and Shu Wang
Plants 2023, 12(3), 675; https://doi.org/10.3390/plants12030675 - 03 Feb 2023
Viewed by 1541
Abstract
Grain size and flag leaf angle are two important traits that determining grain yield in rice. However, the mechanisms regulating these two traits remain largely unknown. In this study, a rice long grain 5 (lg5) mutant with a large flag leaf [...] Read more.
Grain size and flag leaf angle are two important traits that determining grain yield in rice. However, the mechanisms regulating these two traits remain largely unknown. In this study, a rice long grain 5 (lg5) mutant with a large flag leaf angle was identified, and map-based cloning revealed that a single base substitution followed by a 2 bp insertion in the LOC_Os05g40384 gene resulted in larger grains, a larger flag leaf angle, and higher plant height than the wild type. Sequence analysis revealed that lg5 is a novel allele of elongated uppermost internode-1 (EUI1), which encodes a cytochrome P450 protein. Functional complementation and overexpression tests showed that LG5 can rescue the bigger grain size and larger flag leaf angle in the Xiushui11 (XS) background. Knockdown of the LG5 transcription level by RNA interference resulted in elevated grain size and flag leaf angle in the Nipponbare (NIP) background. Morphological and cellular analyses suggested that LG5 regulated grain size and flag leaf angle by promoting cell expansion and cell proliferation. Our results provided new insight into the functions of EUI1 in rice, especially in regulating grain size and flag leaf angle, indicating a potential target for the improvement of rice breeding. Full article
(This article belongs to the Special Issue Rice Genetics and Breeding)
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15 pages, 3791 KiB  
Article
Assessing Effect of Rootstock Micropropagation on Field Performance of Grafted Peach Varieties by Fitting Mixed-Effects Models: A Longitudinal Study
by Juan A. Marín, Elena García, Pilar Lorente, Pilar Andreu and Arancha Arbeloa
Plants 2023, 12(3), 674; https://doi.org/10.3390/plants12030674 - 03 Feb 2023
Viewed by 1200
Abstract
Rootstock micropropagation has been extensively used as an alternative to propagation by cuttings. Although studies have recently been conducted on other species, no conclusive reports have been published on the effect of rootstock micropropagation on the field performance of fruit trees. Here, we [...] Read more.
Rootstock micropropagation has been extensively used as an alternative to propagation by cuttings. Although studies have recently been conducted on other species, no conclusive reports have been published on the effect of rootstock micropropagation on the field performance of fruit trees. Here, we present the results of a five-year study of peach varieties grafted on two rootstocks (Adesoto 101 and Adafuel), either micropropagated or propagated by cuttings, to ascertain the effect of the rootstock propagation method on field performance. Fruit trees are woody plants with a long life cycle; so, to reduce the influence of environmental or cultural factors on the agronomical results, studies need to last for several years, in which data are obtained from the same individuals over time (longitudinal data). This hinders the analysis because these data lack independence. In contrast with a more traditional approach with data aggregation and repeated-measures ANOVA analysis, in this study, we used linear mixed-effects models to control the variance associated with random factors without data aggregation. The growth of the fruit trees did not appreciably differ between the rootstock propagation methods, neither in the flowering period nor in the yield. The models constructed for different parameters of the field performance (trunk cross-sectional area (TCSA), cumulative yield, cumulative yield efficiency, and cumulative crop load) showed a very good fit (R2 > 0.97), allowing the conclusion that the rootstock propagation method did not affect the field performance of fruit trees in this study. Full article
(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)
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18 pages, 4701 KiB  
Article
Enzymatic Antioxidant System Activation Assures the Viability of Guadua chacoensis (Bambusoideae, Poaceae) Embryogenic Cultures during Cryopreservation
by Luiza Giacomolli Polesi, Daniela Goeten, Hugo Pacheco de Freitas Fraga, Neusa Steiner and Miguel Pedro Guerra
Plants 2023, 12(3), 673; https://doi.org/10.3390/plants12030673 - 03 Feb 2023
Cited by 1 | Viewed by 1459
Abstract
This study aimed to establish a cryopreservation protocol for G. chacoensis embryogenic cultures (ECs) and to investigate the role of antioxidant enzymes activities during cryopreservation. The growth dynamics of cell suspensions were also investigated, followed by a phytotoxicity test to assess the ECs’ [...] Read more.
This study aimed to establish a cryopreservation protocol for G. chacoensis embryogenic cultures (ECs) and to investigate the role of antioxidant enzymes activities during cryopreservation. The growth dynamics of cell suspensions were also investigated, followed by a phytotoxicity test to assess the ECs’ ability to tolerate the use of cryoprotective solutions for different incubation times (0, 30, 60, 120, and 240 min). We evaluated the EC redox state in three steps of cryopreservation: after incubation in cryoprotection solution, after thawing, and 60 days after regrowth. Our results showed that the ECs support the use of cryoprotective solution until 120 min, showing phytotoxic effects with 240 min of incubation. This study reports a 100% survival of the cultures and a 10% increase ratio in fresh material for both incubation times tested (60 and 120 min). Increased malonaldehyde content was identified after incubation in the cryoprotective solution. An increase in the activities of catalase and ascorbate peroxidase was also identified in the subsequent steps, suggesting that the activation of antioxidant enzymes is essential for maintaining cell homeostasis during cryopreservation. Full article
(This article belongs to the Special Issue Somatic Embryogenesis and Plant Regeneration)
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12 pages, 688 KiB  
Article
Antifungal In Vitro Activity of Phoradendron sp. Extracts on Fungal Isolates from Tomato Crop
by Alma Leticia Salas-Gómez, César Alejandro Espinoza Ahumada, Rocío Guadalupe Castillo Godina, Juan Alberto Ascacio-Valdés, Raúl Rodríguez-Herrera, Ma. Teresa de Jesús Segura Martínez, Efraín Neri Ramírez, Benigno Estrada Drouaillet and Eduardo Osorio-Hernández
Plants 2023, 12(3), 672; https://doi.org/10.3390/plants12030672 - 03 Feb 2023
Cited by 1 | Viewed by 1749
Abstract
Synthetic chemicals are mainly used for the control of fungal diseases in tomato, causing the phytopathogens to generate resistance to the chemical active ingredient, with a consequent risk to human health and the environment. The use of plant extracts is an option for [...] Read more.
Synthetic chemicals are mainly used for the control of fungal diseases in tomato, causing the phytopathogens to generate resistance to the chemical active ingredient, with a consequent risk to human health and the environment. The use of plant extracts is an option for the control of these diseases, which is why the main objective of this research was to study an alternative biocontrol strategy for the management of plant diseases caused by fungi through obtaining polyphenol extracts from mistletoe plants growing on three different tree species—mesquite (Prosopis glandulosa), cedar (Cedrus), and oak (Quercus), which contain flavones, anthocyanins, and luteolin. The overall chemical structure of the obtained plant extracts was investigated by RP-HPLC-ESI-MS liquid chromatography. The antifungal effect of these extracts was examined. The target phytopathogenic fungi were isolated from tomato plantations located in Altamira, Tamaulipas, Mexico. The microorganisms were characterized by classical and molecular methods and identified as Alternaria alternata, Fusarium oxysporum, Fusarium sp., and Rhizoctonia solani. Full article
(This article belongs to the Special Issue Agricultural Microbiology)
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12 pages, 6605 KiB  
Article
Effect of Pre-Storage CO2 Treatment and Modified Atmosphere Packaging on Sweet Pepper Chilling Injury
by Abiodun Samuel Afolabi, In-Lee Choi, Joo Hwan Lee, Yong Beom Kwon, Hyuk Sung Yoon and Ho-Min Kang
Plants 2023, 12(3), 671; https://doi.org/10.3390/plants12030671 - 03 Feb 2023
Cited by 4 | Viewed by 1482
Abstract
The effect of 10% CO2 pre-storage treatment for 12, 24, and 48 h alongside modified atmosphere packaging (MAP) on chilling injury was determined in this study. This study found significant interactions between chilling injuries and cell membrane damage indicators. The results show [...] Read more.
The effect of 10% CO2 pre-storage treatment for 12, 24, and 48 h alongside modified atmosphere packaging (MAP) on chilling injury was determined in this study. This study found significant interactions between chilling injuries and cell membrane damage indicators. The results show that chilling injuries can be somewhat reduced by the use of CO2 treatment for sweet peppers. It was noticed that the fruit’s respiration rate increased as the treatment duration increased immediately after the treatments, while the resultant did not affect the ethylene production rate, electrolyte leakage, or malondialdehyde. Similarly, after cold storage and on the final day, no really significant differences were shown in all those parameters except for the weight loss rate, chilling injury, calyx browning, and firmness, which were at the poorest state in the control group. Of all the treatments in this study, MAP appeared to be the best treatment, and preference may be given to the 24 h treatment of pretreated fruits. Weight loss, firmness, calyx browning, and chilling injury were maintained best in MAP due to the presence of CO2 and high humidity. Full article
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15 pages, 1302 KiB  
Article
The Interactive Effects of Deficit Irrigation and Bacillus pumilus Inoculation on Growth and Physiology of Tomato Plant
by Jie Liu, Jiarui Zhang, Qimiao Shi, Xiangliang Liu, Zhen Yang, Pan Han, Jingjing Li, Zhenhua Wei, Tiantian Hu and Fulai Liu
Plants 2023, 12(3), 670; https://doi.org/10.3390/plants12030670 - 03 Feb 2023
Cited by 3 | Viewed by 1453
Abstract
The effects of inoculating plant growth promoting rhizobacteria (PGPR) and soil water deficits on crop growth and physiology remain largely unknown. Here, the responses of leaf gas exchange, growth, and water use efficiency (WUE) of tomato plants to Bacillus pumilus (B.p.) [...] Read more.
The effects of inoculating plant growth promoting rhizobacteria (PGPR) and soil water deficits on crop growth and physiology remain largely unknown. Here, the responses of leaf gas exchange, growth, and water use efficiency (WUE) of tomato plants to Bacillus pumilus (B.p.) inoculation under four irrigation strategies (I1-I4) were investigated in a greenhouse. Results showed that soil water deficits, especially at I4 (20%, v/v), significantly decreased leaf stomatal conductance (gs), transpiration rate (Tr), and photosynthetic rate (An), and the decrease of gs and Tr were more pronounced than An. Reduced irrigation regimes significantly lowered dry matter and plant water use both in the non-B.p. control and the B.p. plants, while reduced irrigation significantly increased plant WUE, and B.p. inoculation had little effect on this parameter. Synergistic effects of PGPR and deficit irrigation on leaf gas exchange, leaf abscisic acid content, and stomatal density were found in this study, and specifically, B.p. treated plants at I4 possessed the highest WUE at stomatal and leaf scales, suggesting that B.p. inoculation could optimize water use and partly alleviate the negative effects of soil water deficit. These findings provide useful information for effective irrigation management and the application of PGPR in agriculture in the future. Full article
(This article belongs to the Topic Plant-Soil Interactions)
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25 pages, 2940 KiB  
Review
Overview of Repressive miRNA Regulation by Short Tandem Target Mimic (STTM): Applications and Impact on Plant Biology
by Syed Muhammad Iqbal Syed Othman, Arif Faisal Mustaffa, M. Hafiz Che-Othman, Abdul Fatah A. Samad, Hoe-Han Goh, Zamri Zainal and Ismanizan Ismail
Plants 2023, 12(3), 669; https://doi.org/10.3390/plants12030669 - 03 Feb 2023
Cited by 2 | Viewed by 2982
Abstract
The application of miRNA mimic technology for silencing mature miRNA began in 2007. This technique originated from the discovery of the INDUCED BY PHOSPHATE STARVATION 1 (IPS1) gene, which was found to be a competitive mimic that prevents the cleavage of [...] Read more.
The application of miRNA mimic technology for silencing mature miRNA began in 2007. This technique originated from the discovery of the INDUCED BY PHOSPHATE STARVATION 1 (IPS1) gene, which was found to be a competitive mimic that prevents the cleavage of the targeted mRNA by miRNA inhibition at the post-transcriptional level. To date, various studies have been conducted to understand the molecular mimic mechanism and to improve the efficiency of this technology. As a result, several mimic tools have been developed: target mimicry (TM), short tandem target mimic (STTM), and molecular sponges (SPs). STTM is the most-developed tool due to its stability and effectiveness in decoying miRNA. This review discusses the application of STTM technology on the loss-of-function studies of miRNA and members from diverse plant species. A modified STTM approach for studying the function of miRNA with spatial–temporal expression under the control of specific promoters is further explored. STTM technology will enhance our understanding of the miRNA activity in plant-tissue-specific development and stress responses for applications in improving plant traits via miRNA regulation. Full article
(This article belongs to the Section Plant Molecular Biology)
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19 pages, 5480 KiB  
Article
Effectiveness of Endophytic and Rhizospheric Bacteria from Moringa spp. in Controlling Pythium aphanidermatum Damping-Off of Cabbage
by Buthaina Aamir Ali Al-Rahbi, Abdullah Mohammed Al-Sadi, Majida Mohammed Ali Al-Harrasi, Jamal Nasser Al-Sabahi, Issa Hashil Al-Mahmooli, Daniel Blackburn and Rethinasamy Velazhahan
Plants 2023, 12(3), 668; https://doi.org/10.3390/plants12030668 - 02 Feb 2023
Cited by 3 | Viewed by 2211
Abstract
In this study, endophytic and rhizospheric bacteria were isolated from Moringa olifera and M. perigreina from Oman, and their in vitro antagonistic activity against Pythium aphanidermatum was tested using a dual culture assay. The promising strains were tested further for their compatibility and [...] Read more.
In this study, endophytic and rhizospheric bacteria were isolated from Moringa olifera and M. perigreina from Oman, and their in vitro antagonistic activity against Pythium aphanidermatum was tested using a dual culture assay. The promising strains were tested further for their compatibility and potential for plant growth promotion, biofilm formation, antifungal volatile organic compound (VOC) production, and the biological control of P. aphanidermatum damping-off of cabbage (Brassica oleracea L.) under greenhouse conditions. A total of 12 endophytic and 27 rhizospheric bacteria were isolated from Moringa spp. Among them, Bacillus pumilus MPE1 showed the maximum antagonistic activity against P. aphanidermatum in the dual culture assay, followed by Paenibacillus glucanolyticus MPE3 and Pseudomonas indica MOR3 and MOR8. These bacterial isolates induced abundant morphological abnormalities in the hyphae of P. aphanidermatum, as observed via scanning electron microscopy. The in vitro cross-streak assay showed that these bacterial isolates were compatible among themselves, except for P. indica MOR8 × P. glucanolyticus MPE3. These antagonists released VOCs that restricted the growth of P. aphanidermatum in an in vitro assay. These antagonistic bacteria released 2,4-dimethylheptane and 4-methyloctane as the predominant volatile compounds. Of the four antagonistic bacterial strains, P. indica MOR8 was capable of forming biofilm, which is considered a trait that improves the efficacy of rhizosphere inoculants. The results of the greenhouse experiments showed that the soil treatment with B. pumilus MPE1 showed the highest reduction (59%) in the incidence of P. aphanidermatum damping-off in cabbage, evidencing its potential as a biological control agent for the management of this disease. Further research is needed to characterize the antifungal traits and activities of B. pumilus MPE1 and to assert its potential use against other soil-borne plant pathogens. Full article
(This article belongs to the Special Issue Novel Biocontrol Tools and Resources for Plant Protection)
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11 pages, 1738 KiB  
Article
Comparison of Serological and Molecular Methods for Detection of Spiroplasma citri in Moroccan Citrus-Growing Areas
by Tourya Sagouti, Naima Rhallabi, Giancarlo Polizzi, Abdessalem Tahiri, Zineb Belabess, Essaid Ait Barka and Rachid Lahlali
Plants 2023, 12(3), 667; https://doi.org/10.3390/plants12030667 - 02 Feb 2023
Viewed by 1293
Abstract
Spiroplasma citri, a helical motile, wall-less, and cultivable microorganism of the class Mollicutes, is the agent of the citrus stubborn disease. There is currently a lack of data about the presence of this pathogen in Moroccan citrus orchards. This study aims to validate [...] Read more.
Spiroplasma citri, a helical motile, wall-less, and cultivable microorganism of the class Mollicutes, is the agent of the citrus stubborn disease. There is currently a lack of data about the presence of this pathogen in Moroccan citrus orchards. This study aims to validate serological and molecular methods for routine S. citri diagnosis in Moroccan citrus groves. To provide an update on the present status of the outbreak of the pathogen in Moroccan citrus orchards, a survey of S. citri was conducted in the main citrus-growing regions of Morocco. A total of 575 leaf samples were collected from citrus trees with symptoms attributable to S. citri infection. Samples were collected during 2020 and 2021 from 23 citrus orchards. The presence of S. citri was tested in all samples using the double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Using this method, 57 samples were found to be infected with S. citri, 41 samples had doubtful results, and the remaining samples were negative. To corroborate the results of the DAS-ELISA test, 148 samples were chosen for additional molecular testing using conventional polymerase chain reaction (PCR) and real-time PCR (qPCR) based on specific primer pairs targeting three different genes (putative adhesion-like gene P58, putative adhesion gene P89, and spiralin gene). Using primers that target the putative adhesion-like gene P58, S. citri was detected by conventional and real-time PCR amplification from plant tissue with differing degrees of specificity. The results allowed us to determine the incidence of S. citri in all Moroccan citrus orchards, with a wide range of positive samples varying from 6.5% to 78%, and to show that molecular tests, particularly real-time PCR assays that target the putative adhesion-like gene P58, are the most sensitive for making an accurate diagnosis of S. citri. Indeed, the real-time PCR with P58-targeting primers yielded positive results from all positive and doubtful ELISA samples as well as some negative samples, with an OD value close to 1.5× times healthy samples, thus demonstrating a high sensibility of this technique. Full article
(This article belongs to the Special Issue Crops Diseases under Climate Change Context and Their Control)
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23 pages, 2169 KiB  
Article
High Temperature Alters Phenology, Seed Development and Yield in Three Rice Varieties
by Pranee Sanwong, Jirawat Sanitchon, Anoma Dongsansuk and Darunee Jothityangkoon
Plants 2023, 12(3), 666; https://doi.org/10.3390/plants12030666 - 02 Feb 2023
Cited by 2 | Viewed by 1445
Abstract
Rice is an important and main staple food crop. Rice in Thailand grows in both the on- and off-seasons. The problem of growing rice in the off-season is that it is dry and the temperature tends to be high. To evaluate the effects [...] Read more.
Rice is an important and main staple food crop. Rice in Thailand grows in both the on- and off-seasons. The problem of growing rice in the off-season is that it is dry and the temperature tends to be high. To evaluate the effects of high temperatures on their phenology, yield and seed quality, three rice varieties were cultivated off-season in 2018 and 2019. Rice plants were grown in cement pots on planting date I (PDI; off-season; mid-January) and planting date II (PDII; late off-season; beginning of February). The results showed that rice plants were exposed to higher temperatures in 2019 (than 2018), as indicated by a higher accumulated growing degree day (AGDD). The high AGDD affected the phenology of the rice by shortening the duration of its development from sowing to physiological maturity (PM) from 106.8 DAS in 2018 to 86.0 DAS in 2019. The high AGDD shortened the development duration of the embryo and endosperm, resulting in reductions in the size and growth rates of the embryo and endosperm, and eventually reduced the yield and the yield components. Moreover, the high AGDD reduced the seed quality, as indicated by a decline in the seedling growth rate (SGR) and an increase in chalkiness. Among the varieties, the high temperature in 2019 caused the smallest phenological shift in Chai Nat 1 (CN1), while the shift was largest in Pathum Thani 1 (PTT1). In addition, CN1 exhibited a significantly higher total seed weight/panicle, 1000-seed weight and percentage of filled seed/pot than SP1 and PPT1. It was suggested that CN1 could be described as heat tolerant, and PTT1 as heat sensitive. It was also suggested that farmers should select appropriate rice varieties to grow in the off-season due to the risk of a high-temperature-induced reduction in the seed yield and quality. Full article
(This article belongs to the Topic Temperature Stress and Responses in Plants)
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18 pages, 5052 KiB  
Article
Effects of Mycotoxin Fumagillin, Mevastatin, Radicicol, and Wortmannin on Photosynthesis of Chlamydomonas reinhardtii
by Jiale Shi, Mengyun Jiang, He Wang, Zhi Luo, Yanjing Guo, Ying Chen, Xiaoxi Zhao, Sheng Qiang, Reto Jörg Strasser, Hazem M. Kalaji and Shiguo Chen
Plants 2023, 12(3), 665; https://doi.org/10.3390/plants12030665 - 02 Feb 2023
Cited by 1 | Viewed by 1378
Abstract
Mycotoxins are one of the most important sources for the discovery of new pesticides and drugs because of their chemical structural diversity and fascinating bioactivity as well as unique novel targets. Here, the effects of four mycotoxins, fumagillin, mevastatin, radicicol, and wortmannin, on [...] Read more.
Mycotoxins are one of the most important sources for the discovery of new pesticides and drugs because of their chemical structural diversity and fascinating bioactivity as well as unique novel targets. Here, the effects of four mycotoxins, fumagillin, mevastatin, radicicol, and wortmannin, on photosynthesis were investigated to identify their precise sites of action on the photosynthetic apparatus of Chlamydomonas reinhardtii. Our results showed that these four mycotoxins have multiple targets, acting mainly on photosystem II (PSII). Their mode of action is similar to that of diuron, inhibiting electron flow beyond the primary quinone electron acceptor (QA) by binding to the secondary quinone electron acceptor (QB) site of the D1 protein, thereby affecting photosynthesis. The results of PSII oxygen evolution rate and chlorophyll (Chl) a fluorescence imaging suggested that fumagillin strongly inhibited overall PSII activity; the other three toxins also exhibited a negative influence at the high concentration. Chl a fluorescence kinetics and the JIP test showed that the inhibition of electron transport beyond QA was the most significant feature of the four mycotoxins. Fumagillin decreased the rate of O2 evolution by interrupting electron transfer on the PSII acceptor side, and had multiple negative effects on the primary photochemical reaction and PSII antenna size. Mevastatin caused a decrease in photosynthetic activity, mainly due to the inhibition of electron transport. Both radicicol and wortmannin decreased photosynthetic efficiency, mainly by inhibiting the electron transport efficiency of the PSII acceptor side and the activity of the PSII reaction centers. In addition, radicicol reduced the primary photochemical reaction efficiency and antenna size. The simulated molecular model of the four mycotoxins’ binding to C. reinhardtii D1 protein indicated that the residue D1-Phe265 is their common site at the QB site. This is a novel target site different from those of commercial PSII herbicides. Thus, the interesting effects of the four mycotoxins on PSII suggested that they provide new ideas for the design of novel and efficient herbicide molecules. Full article
(This article belongs to the Special Issue Bioherbicide Development for Weed Control)
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20 pages, 2914 KiB  
Article
Ozone and Temperature May Hinder Adaptive Capacity of Mediterranean Perennial Grasses to Future Global Change Scenarios
by Samuel Prieto-Benítez, Raquel Ruiz-Checa, Ignacio González-Fernández, Susana Elvira, Isabel Rucandio, Rocío Alonso and Victoria Bermejo-Bermejo
Plants 2023, 12(3), 664; https://doi.org/10.3390/plants12030664 - 02 Feb 2023
Viewed by 1472
Abstract
Climate warming is recognized as a factor that threatens plant species in Mediterranean mountains. Tropospheric ozone (O3) should also be considered as another relevant stress factor for these ecosystems since current levels chronically exceed thresholds for plant protection in these areas. [...] Read more.
Climate warming is recognized as a factor that threatens plant species in Mediterranean mountains. Tropospheric ozone (O3) should also be considered as another relevant stress factor for these ecosystems since current levels chronically exceed thresholds for plant protection in these areas. The main aim of the present study was to study the sensitivity of four Mediterranean perennial grasses to O3 and temperature based on plant growth, gas exchange parameters (photosynthesis—A, stomatal conductance—gs, and water use efficiency—WUE), and foliar macro- (N, K, Ca, Mg, P, and S) and micronutrients (B, Cu, Fe, Mn, Mo, and Zn) content. The selected species were grasses inhabiting different Mediterranean habitats from mountain-top to semi-arid grasslands. Plants were exposed to four O3 treatments in Open-Top chambers, ranging from preindustrial to above ambient levels, representing predicted future levels. Chamber-less plots were considered to study the effect of temperature increase. Despite the general tolerance of the grasses to O3 and temperature in terms of biomass growth, WUE and foliar nutrient composition were the most affected parameters. The grass species studied showed some degree of similarity in their response to temperature, more related with phylogeny than to their tolerance to drought. In some species, O3 or temperature stress resulted in low A or WUE, which can potentially hinder plant tolerance to climate change. The relationship between O3 and temperature effects on foliar nutrient composition and plant responses in terms of vegetative growth, A, gs, and WUE constitute a complex web of interactions that merits further study. In conclusion, both O3 and temperature might be modifying the adaptation capacity of Mediterranean perennial grass species to the global change. Air pollution should be considered among the driving favors of biodiversity changes in Mediterranean grassland habitats. Full article
(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)
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14 pages, 3417 KiB  
Article
Phytotoxicity of Quillaja lancifolia Leaf Saponins and Their Bioherbicide Potential
by Maria E. M. Marques, Ana C. de Carvalho, Anna C. A. Yendo, Yve V. S. Magedans, Eliane Zachert and Arthur G. Fett-Neto
Plants 2023, 12(3), 663; https://doi.org/10.3390/plants12030663 - 02 Feb 2023
Viewed by 1727
Abstract
Weeds are major threats to the integrity of agricultural and natural environments due to their invasive and competing potential. Bioherbicides are substances based on natural compounds that are biodegradable and often have low residual effects. Plant species able to produce and release phytotoxic [...] Read more.
Weeds are major threats to the integrity of agricultural and natural environments due to their invasive and competing potential. Bioherbicides are substances based on natural compounds that are biodegradable and often have low residual effects. Plant species able to produce and release phytotoxic compounds may represent effective bioherbicide sources. Leaves of Quillaja lancifolia D.Don (formerly Q. brasiliensis (A.St.-Hil. & Tul.) Mart.) produce water-soluble specialized metabolites of the saponin class that could be evaluated for phytotoxic activity and potential as natural herbicides. This study was conducted to examine the impacts of Q. lancifolia total saponins aqueous extract (AE) at 4 and 10% (w/v) and of two combined reverse-phase chromatography purified saponin fractions (QB) at 1 and 2% (w/v) on morpho-physiological parameters of Lactuca sativa (lettuce) and Echinochloa crus-galli (barnyardgrass) in pre- and post-emergence bioassays. QB was only tested in pre-emergence assays. In pre-emergence bioassays, the germination rate and germination kinetics were determined. Post-emergence evaluations included effects on seedling morphology, root and shoot length, dry mass, and chlorophyll content. Osmotic potential and pH analyses ruled out roles for these factors in the observed responses. AE had a high inhibitory impact on the germination of both lettuce and barnyardgrass. QB at 1% and 2% (w/v) significantly decreased the growth of lettuce seedlings germinated in its presence by more than 10-fold. Phytotoxic effects on the post-emergence growth of lettuce, especially at the highest concentration tested of AE (10% w/v), was also observed. The presence of quillaic acid-based triterpene saponins in AE and QB was confirmed using different analytical methods. Therefore, both saponin-enriched fraction and aqueous extracts of Q. lancifolia inhibited tested plant growth and development. The water solubility of saponins and the availability of a sustainable source of these molecules from the leaves of cultivated young Q. lancifolia plants make them attractive candidates for use as bioherbicides. Full article
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21 pages, 5260 KiB  
Article
Promising Bioregulators for Higher Water Productivity and Oil Quality of Chia under Deficit Irrigation in Semiarid Regions
by Chowdasandra Byregowda Harisha, Vijaykumar B. Narayanpur, Jagadish Rane, Vasant M. Ganiger, Sugooru M. Prasanna, Yeragenahalli Chandrashekaharappa Vishwanath, Sanjeevraddi G. Reddi, Hanamant M. Halli, Karnar Manjanna Boraiah, Patil Siddanagouda Basavaraj, Eman A. Mahmoud, Ryan Casini and Hosam O. Elansary
Plants 2023, 12(3), 662; https://doi.org/10.3390/plants12030662 - 02 Feb 2023
Cited by 3 | Viewed by 1584
Abstract
Appropriate water management practices are essential for the successful cultivation of chia in water-scarce situations of semiarid regions. This is highly essential when new crops such as chia are introduced for ensuring diversity and water saving. Therefore, field trials (2020–21 and 2021–22) were [...] Read more.
Appropriate water management practices are essential for the successful cultivation of chia in water-scarce situations of semiarid regions. This is highly essential when new crops such as chia are introduced for ensuring diversity and water saving. Therefore, field trials (2020–21 and 2021–22) were conducted to understand the impact of deficit irrigation and bioregulators (BRs) on the seed yield, water productivity, and oil quality of chia. The effect of foliar application of BRs such as thiourea (TU; 400 ppm), salicylic acid (SA; 1.0 mM), potassium nitrate (KN; 0.15%), potassium silicate (KS; 100 ppm), kaolin (KO; 5%), and sodium benzoate (SB; 200 ppm) were monitored at different levels of irrigation: 100 (I100), 75 (I75), 50 (I50), and 25 (I25) percent of cumulative pan evaporation (CPE). Deficit irrigation at I25, I50, and I75 led to 55.3, 20.1, and 3.3% reductions in seed yield; 42.5, 22.5, and 4.2% in oil yield; and 58.9, 24.5, and 5.7% in omega–3 yield, respectively, relative to I100. Bioregulators could reduce the adverse impact of water deficit stress on seed, oil, and omega–3 yield. However, their beneficial effect was more conspicuous under mild water stress (I75), as revealed by higher seed yield (4.3–6.9%), oil yield (4.4–7.1%), and omega–3 yield (4.7–8.5%) over control (I100 + no BRs). Further, BRs (KN, TU, and SA) maintained oil quality in terms of linolenic acid and polyunsaturated fatty acid contents, even under mild stress (I75). Foliar application of KN, TU, and SA could save water to an extent of 36–40%. Therefore, the adverse impact of deficit irrigation on seed, oil, and omega–3 yields of chia could be minimized using BRs such as KN, TU, and SA, which can also contribute to improved water productivity. Full article
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12 pages, 2860 KiB  
Systematic Review
Public Health Implications of Invasive Plants: A Scientometric Study
by Camila Denóbile, Wagner Antonio Chiba de Castro and Dalva Maria da Silva Matos
Plants 2023, 12(3), 661; https://doi.org/10.3390/plants12030661 - 02 Feb 2023
Cited by 1 | Viewed by 2138
Abstract
Movements of organisms through distinct places can change the dynamics of ecological interactions and make the habitat conducive to the spread of diseases. Faced with a cyclical scenario of invasions and threats in a One Health context, we conducted a scientometric study to [...] Read more.
Movements of organisms through distinct places can change the dynamics of ecological interactions and make the habitat conducive to the spread of diseases. Faced with a cyclical scenario of invasions and threats in a One Health context, we conducted a scientometric study to understand how disturbances in environments with invaded vegetation affect the incidence of parasites and disease prevalence rates. The search was carried out in Web of Science and Scopus databases, with keywords delimited by Boolean operators and based on the PRISMA protocol. Thirty-sixarticles were full-read to clarify the interaction between diseases and invaded areas. The analysis covered publications from 2005 to 2022, with a considerable increase in the last ten years and a significant participation of the USA on the world stage. Trends were found in scientific activities, and we explored how invasive species can indirectly damage health, as higher concentrations of pathogens, vectors, and hosts were related to structurally altered communities. This paper reveals invaded plants threats that enhance disease transmission risks. It is likely that, with frequent growth in the number of introduced species worldwide due to environmental disturbances and human interventions, the negative implications will be intensified in the coming years. Full article
(This article belongs to the Special Issue Plant Invasion 2022)
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18 pages, 5656 KiB  
Article
Triazoles and Strobilurin Mixture Affects Soil Microbial Community and Incidences of Wheat Diseases
by Anastasia V. Vasilchenko, Darya V. Poshvina, Mikhail V. Semenov, Vyacheslav N. Timofeev, Alexandr V. Iashnikov, Artyom A. Stepanov, Arina N. Pervushina and Alexey S. Vasilchenko
Plants 2023, 12(3), 660; https://doi.org/10.3390/plants12030660 - 02 Feb 2023
Cited by 4 | Viewed by 2139
Abstract
Pesticides are widely used in agriculture as a pest control strategy. Despite the benefits of pesticides on crop yields, the persistence of chemical residues in soil has an unintended impact on non-targeted microorganisms. In the present study, we evaluated the potential adverse effects [...] Read more.
Pesticides are widely used in agriculture as a pest control strategy. Despite the benefits of pesticides on crop yields, the persistence of chemical residues in soil has an unintended impact on non-targeted microorganisms. In the present study, we evaluated the potential adverse effects of a mixture of fungicides (difenoconazole, epoxiconazole, and kresoxim-methyl) on soil fungal and bacterial communities, as well as the manifestation of wheat diseases. In the fungicide-treated soil, the Shannon indices of both fungal and bacterial communities decreased, whereas the Chao1 indices did not differ compared to the control soil. Among bacterial taxa, the relative abundances of Arthrobacter and Sphingomonas increased in fungicide-treated soil due to their ability to utilize fungicides and other toxic compounds. Rhizopus and plant-beneficial Chaetomium were the dominant fungal genera, with their prevalence increasing by 2–4 times in the fungicide-treated soil. The genus Fusarium, which includes phytopathogenic species, which are notably responsible for root rot, was the most abundant taxon in each of the two conditions but its relative abundance was two times lower in fungicide-treated soils, consistent with a lower level of disease incidence in plants. The prediction of metabolic pathways revealed that the soil bacterial community had a high potential for degrading various pollutants, and the soil fungal community was in a state of recovery after the application of quinone outside inhibitor (QoI) fungicides. Fungicide-treated soil was characterized by an increase in soil microbial carbon, compared with the control soil. Collectively, the obtained results suggest that the application of difenoconazole, epoxiconazole, and kresoxim-methyl is an effective approach for pest control that does not pose a hazard for the soil ecosystem in the short term. However, it is necessary to carry out additional sampling to take into account the spatio-temporal impact of this fungicide mixture on the functional properties of the soil. Full article
(This article belongs to the Special Issue Phytomicrobiome Research for Disease and Pathogen Management)
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