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Sargassum is exploited as a biostimulant in agriculture for its rich bioactive compounds. Extracts from Sargassum promote plant growth, nutrient uptake, and stress tolerance in agricultural and horticultural crops. Sargassum is a most abundant seaweed, and it occupies a huge proportion of coastal plants. This review unveils key active constituents present in Sargassum such as proximate and ultimate compounds, antioxidants, phytohormones, glucosinoids, bioactive compounds, and enzymes. As a biostimulant, Sargassum mitigates biotic and abiotic stresses. It has a positive impact on soil health, plant physiology, crop yield, animal antimicrobials, and animal feeding, as well as highlighting some sustainable agricultural practices discussed in the review. Integrating Sargassum-based biostimulants in agriculture holds promise for resilient and productive crops with minimal environmental impact. These characteristics are considered the future of ideal agrochemical properties in all dimensions of plant growth and development. These kinds of organic-based biostimulants will be ideal alternatives to toxic chemical agents. [ABSTRACT FROM AUTHOR]

Growth, productivity, and fiber quality of cotton (Gossypium hirsutum L.), a vital fiber-producing cash crop, are severely affected under drought conditions. Seed priming has a proven role in enhancing crop tolerance to abiotic stress, including drought. The objective of this study was to evaluate the effects of seed priming with KNO3 on cotton productivity and fiber quality under drought stress. A germination experiment was established under laboratory conditions with five treatments of seed priming (non-primed or control treatment, hydropriming, and priming with 2.5, 5.0, and 7.5 g KNO3 L−1). Another experiment under polyhouse conditions based on the same seed priming treatments was conducted under three levels of soil water contents (field capacity [FC] 100%: FC100, 75%: FC75, and 50%: FC50). The results obtained showed that there was a clear reduction in the different parameters tested at FC50 in comparison to FC100 (39–54%, 32–44%, 6–12%, and 7–12% reduction for boll number per plant, seed cotton yield, fiber strength, and leaf relative water content, respectively, across all priming treatments). Seed priming with KNO3 at 5 g L−1 effectively alleviated the detrimental effects originated from drought stress and caused 61–73%, 13–16%, and 16–23% increase in seed cotton yield, fiber length, and fiber strength, respectively, across soil moisture levels when compared with the control treatment. The same KNO3 dose caused an increase of 78% in water productivity in comparison to the control plants at FC50. Priming cotton seeds with 5 g KNO3 L−1 holds promise to obtain synchronized germination, enhance fiber quality, and increase yield, especially under water-limited conditions, thereby promoting economic viability and environmental sustainability. Additionally, this practice enhances water productivity, leading to significant water savings and reduced irrigation costs for cotton farmers. This method could be used as potential technology in advancing sustainable agriculture in water-constraint conditions. [ABSTRACT FROM AUTHOR]

Every year, unfavorable environmental factors significantly affect crop productivity and threaten food security. Plants are sessile; they cannot move to escape unfavorable environmental conditions, and therefore, they activate a variety of defense pathways. Among them are processes regulated by stress‐associated proteins (SAPs). SAPs have a specific zinc finger domain (A20) at the N‐terminus and either AN1 or C2H2 at the C‐terminus. SAP proteins are involved in many biological processes and in response to various abiotic or biotic constraints. Most SAPs play a role in conferring transgenic stress resistance and are stress‐inducible. The emerging field of SAPs in abiotic or biotic stress response regulation has attracted the attention of researchers. Although SAPs interact with various proteins to perform their functions, the exact mechanisms of these interactions remain incompletely understood. This review aims to provide a comprehensive understanding of SAPs, covering their diversity, structure, expression, and subcellular localization. SAPs play a pivotal role in enabling crosstalk between abiotic and biotic stress signaling pathways, making them essential for developing stress‐tolerant crops without yield penalties. Collectively, understanding the complex regulation of SAPs in stress responses can contribute to enhancing tolerance against various environmental stresses through several techniques such as transgenesis, classical breeding, or gene editing. [ABSTRACT FROM AUTHOR]

Summary: Leaf senescence is a developmental program regulated by both endogenous and environmental cues. Abiotic stresses such as nutrient deprivation can induce premature leaf senescence, which profoundly impacts plant growth and crop yield. However, the molecular mechanisms underlying stress‐induced senescence are not fully understood.In this work, employing a carbon deprivation (C‐deprivation)‐induced senescence assay in Arabidopsis seedlings, we identified PLEIOTROPIC REGULATORY LOCUS 1 (PRL1), a component of the NineTeen Complex, as a negative regulator of C‐deprivation‐induced senescence.Furthermore, we demonstrated that PRL1 directly interacts with the RPA2A subunit of the single‐stranded DNA‐binding Replication Protein A (RPA) complex. Consistently, the loss of RPA2A leads to premature senescence, while increased expression of RPA2A inhibits senescence. Moreover, overexpression of RPA2A reverses the accelerated senescence in prl1 mutants, and the interaction with PRL1 stabilizes RPA2A under C‐deprivation.In summary, our findings reveal the involvement of the PRL1‐RPA2A functional module in C‐deprivation‐induced plant senescence. [ABSTRACT FROM AUTHOR]

Abiotic stresses, such as heat, drought and salinity, affect the development of wheat crop and hinder its expansion to the central region of Brazil. The identification of genotypes tolerant to these conditions is important for improving yield performance. The present research evaluated the impact of different abiotic stresses on germination and seedling development and selected wheat genotypes tolerant to these stresses, using multi-trait analysis. Heat, drought and salinity stresses were induced in seeds of 23 wheat genotypes. Seed germination, seedling length and dry mass were evaluated. An adaptability and stability model and a multi-trait selection index were applied to the data. Drought and salinity negatively affected the development of seedlings of the 23 evaluated genotypes. However, the VI 14055, ORS Madre Pérola and BRS 404 genotypes conferred the best adaptability and stability results and were selected by the MGIDI, which revealed that great performance can be achieved in regions with potential for abiotic stress, in the early stages of development. [ABSTRACT FROM AUTHOR]

Extreme weather events are expected to increase in frequency and intensity in South America, likely causing decreased plant productivity and altering species distributions. Yerba mate (Ilex paraguariensis) is a tree species native to South America and has an ecological, social, and economic importance in several countries. Natural forests and cultivated areas of yerba mate will be endangered by climate change because of the expected reduction in water availability. Here we determined how clonal genotypes of yerba mate (BRS BLD Yari, BRS BLD Aupaba, BRS 408, and EC40) respond to four levels of soil water holding capacity (100%, 80%, 60%, and 40% WHC) over 60 days, by evaluating the plants' morphophysiological and biochemical characteristics. We observed a reduction in plant height and biomass accumulation related to the decrease in water availability; physiological and biochemical parameters indicated that water-deficit stress reduced the plants' C assimilation and increased their production of bioactive compounds. BRS BLD Yari had a higher tolerance to low water availability, with greater biomass accumulation and photosynthetic rates that indicate greater water use efficiency. Understanding how different yerba mate genotypes respond to water deficit is essential for species conservation and developing climate-adapted breeding programs. [ABSTRACT FROM AUTHOR]

Main conclusion: This study identified 82 wheat BRD genes, revealing both conserved evolutionary and functional characteristics across plant species and novel features specific to wheat. GTE8-12 cluster TaBRDs were found as positive response to salt stress. Bromodomain-containing proteins (BRDs) are crucial in histone acetylation “reading” and chromatin remodeling in eukaryotes. Despite some of their members showing importance in various biological processes in plants, our understanding of the BRD family in wheat (Triticum aestivum) remains limited. This study comprehensively analyzes the T. aestivum BRD (TaBRD) family. We identified 82 TaBRD genes in wheat genome encoding hydrophobic proteins with a conserved pocket structure. Phylogenetic analysis classified these genes into 16 distinct clusters, with conserved protein motifs and gene structures within clusters but diverse patterns across clusters. Gene duplication analysis revealed that whole-genome or segmental duplication events were the primary expansion mechanism for the TaBRD family, with purifying selection acting on these genes. Subcellular localization and Gene Ontology (GO) analyses indicated that TaBRD proteins are predominantly nuclear-localized and involved in transcription regulation and RNA metabolism. Promoter analysis and interaction network prediction suggested diverse regulatory mechanisms for TaBRDs. Notably, TaBRDs from the GTE8-12 cluster were enriched with cis-elements responsive to abscisic acid (ABA), methyl jasmonate (MeJA), and light, implying their involvement in physiological functions and abiotic stress responses. Expression analysis confirmed tissue-specific patterns and responsiveness to salinity stress. This comprehensive study enhances our understanding of the BRD family in higher plants and provides a foundation for developing salt-tolerant wheat varieties. [ABSTRACT FROM AUTHOR]

Heavy metal (HM) contaminants are the emerging driving force for reshaping the microflora of plants by eradicating the non-tolerance and non-resistant microbes via their lethal effects. Seeds served as a prime source of ancestral microbial diversity hereditary transfer from generation to generation. However, the problem arises when they got exposed to metal contamination, does metal pollutant disrupt the delicate balance of microbial communities within seeds and lead to shifts in their microflora across generations. In this study, the endophytic community within Zea mays seeds was compared across three distinct regions in Yunnan province, China: a HM-contaminated site Ayika (AK), less-contaminated site Sanduoduo (SD), and a non-contaminated Site Dali (DL). High-throughput sequencing techniques were employed to analyze the microbial communities. A total of 492,177 high-quality reads for bacterial communities and 1,001,229 optimized sequences for fungal communities were obtained. These sequences were assigned to 502 and 239 operational taxonomic units (OTUs) for bacteria and fungi, respectively. A higher diversity was recorded in AK samples than in SD and DL. Microbial community structure analysis showed higher diversity and significant fluctuation in specific taxa abundance in the metal-polluted samples exhibiting higher response of microbial flora to HM. In AK samples, bacterial genera such as Gordonia and Burkholderia-Caballeronia-Paraburkholderia were dominant, while in SD Pseudomonas and Streptomyces were dominant. Among the fungal taxa, Fusarium, Saccharomycopsis, and Lecanicillium were prevalent in HM-contaminated sites. Our finding revealed the influential effect of HM contaminants on reshaping the seed microbiome of the Zea mays, showing both the resilience of certain important microbial taxa as well the shifts in the diversity in the contaminated and pristine conditions. The knowledge will benefit to develop effective soil remediation, reclamation, and crop management techniques, and eventually assisting in the extenuation of metal pollution's adverse effects on plant health and agricultural productivity. [ABSTRACT FROM AUTHOR]

Background: Light is a critical environmental factor in plants, encompassing two vital aspects: intensity and quality. To assess the influence of different light intensities on Origanum majorana L., pots containing the herb were subjected to four levels of light intensity: 20, 50, 70, and 100% natural light. After a 60-day treatment period, the plants were evaluated for metabolite production, including total sugar content, protein, dry weight, antioxidant indices, expression of monoterpenes biosynthesis genes, and essential oil compounds. The experimental design followed a randomized complete blocks format, and statistical analysis of variance was conducted. Results: The results indicated a correlation between increased light intensity and elevated total sugar and protein content, which contributed to improved plant dry weight. The highest levels of hydrogen peroxide and malondialdehyde (MDA) were observed under 100% light intensity. Catalase and superoxide dismutase enzymes exhibited increased activity, with a 4.23-fold and 2.14-fold increase, respectively, under full light. In contrast, peroxidase and polyphenol oxidase enzyme activities decreased by 3.29-fold and 3.24-fold, respectively. As light intensity increases, the expression level of the 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) gene increases. However, beyond a light intensity of 70%, the DXR gene expression level decreased. Furthermore, the expression levels of the cytochrome P450 genes CYP71D178 and CYP71D179 exhibited an increasing trend in response to elevated light intensity. Essential oil content increased from 0.02 to 0.5% until reaching 70% light intensity. However, with further increases in light intensity, the essential oil content decreased by 54 to 0.23%. Conclusions: These findings emphasize the importance of balancing plant growth promotion and stress management under different light conditions. The research suggests that sweet marjoram plants thrive best in unshaded open spaces, resulting in maximum biomass. However, essential oil production decreases under the same conditions. For farmers in areas with an average light intensity of approximately 1700 µmol m−2s−1, it is recommended to cultivate sweet marjoram in shade-free fields to optimize biomass and essential oil production. Towards the end of the growth cycle, it is advisable to use shades that allow 70% of light to pass through. The specific duration of shade implementation can be further explored in future research. [ABSTRACT FROM AUTHOR]

Drought is the major devastating stress affecting plant growth and development. The plant develops some physiological and biochemical changes to withstand drought. The raffinose family of oligosaccharides (RFOs) are sugars that have a significant role in abiotic stress tolerance. Galactinol synthase (EC 2.4.1.123; GolS) initiates the primary step of the RFOs synthesis. Their accumulation implies a role for RFOs in abiotic stress adaptation. The galactinol synthase gene from proso millet was isolated and characterized. Full length proso millet galactinol synthase gene of size ~1,200 bp having 3 exons with 2 introns was isolated and predicted using bioinformatics tools. A high sequence similarity was observed at 97.2, 95.6, 91.8 and 85.4% with Panicum hallii, Panicum virgatum, Setaria italica and Zea mays mRNA, respectively. PmGolS gene expression pattern with respect to drought stress was evaluated in proso millet. PmGolS gene was highly expressed, 40.3 and 23.7-fold in vegetative and reproductive stages of drought-stressed plants respectively compared to control. It suggested that PmGolS gene has an active role in drought stress tolerance. [ABSTRACT FROM AUTHOR]

ABSTRACT Diplodia sapinea causes Diplodia tip blight (DTB) and is recognised as an opportunistic necrotrophic pathogen affecting conifers. While DTB is associated with abiotic stress, the impact of biotic stress in the host on D. sapinea's lifestyle shift is unknown. Observed co‐occurrences of D. sapinea and Melampsora pinitorqua, causing pine twisting rust on Scots pine (Pinus sylvestris), instigated an investigation into their interaction with and influence on the defence mechanisms of the host. We hypothesised that M. pinitorqua infections predispose the trees to D. sapinea by stressing the host and altering the shoot metabolites. Pines in a plantation were sampled over time to study pathogen biomass and host metabolites. Symptoms of both pathogens were consistent over years, and the preceding season's symptoms affected the metabolic profiles pre‐infection and M. pinitorqua's proliferation. Symptoms of M. pinitorqua altered shoot metabolites more than fungal biomass, with co‐symptomatic trees exhibiting elevated M. pinitorqua biomass. Specific phenolic compounds had a strong positive association with the shoot symptom × D. sapinea interaction. D. sapinea's biomass presymptoms was independent of previous disease symptoms and infection by M. pinitorqua. Some trees showed disease tolerance, with delayed rust infections and minimal DTB symptoms. Further investigations on this trait are needed. [ABSTRACT FROM AUTHOR]

Unfavorable environmental conditions pose a major barrier to sustainable agriculture. Among the various innovative strategies developed to protect plants from abiotic stress, the use of phytohormones and nanoparticles as "stress mitigators" has emerged as one of the most important and promising approaches. The objective of this study was to observe the protective role of melatonin (Mel) and silicon oxide nanoparticles (SiO-NPs) in rice (Oryza sativa L.) seedlings under cadmium (Cd) stress. Rice seedlings have reduced growth and phytochemical attributes when grown in Cd-contaminated (0.8 mM) pots. Seedlings under Cd stress had 38% less shoot length (SL), 53% total soluble sugar (TSS) and 57% protein content. However, superoxide dismutase (SOD), hydrogen peroxide (H2O2) and malondialdehyde (MDA) increased by 51%, 37% and 34%, respectively, under Cd stress. Beside this, activities such as peroxidase (POX) also elevated in the plants subjected with Cd-stress. In contrast, Mel (100 μm) as foliar spray and SiO-NPs (100 mg/L) as root dipping reduced oxidative stress in rice seedlings under Cd stress by reducing reactive oxygen species (ROS) generation. Furthermore, the application of Mel and/or SiO-NPs significantly increased the activity of antioxidative enzymes that scavenge ROS. The combined application of SiO-NPs and Mel increased growth, gas exchange and photosynthetic attributes, chlorophyll value, and protein content. It causes alleviation in the activity of SOD, CAT and POX by 73%, 62% and 65%, respectively. Overall, this study findings show that Mel and/or SiO-NPs can potentially protect the rice crop against oxidative damage under Cd stress. [ABSTRACT FROM AUTHOR]

Introduction: NAC (NAM, ATAF, and CUC) transcription factor family, one of the important switches of transcription networks in plants, functions in plant growth, development, and stress resistance. Night lily (Hemerocallis citrina) is an important horticultural perennial monocot plant that has edible, medicinal, and ornamental values. However, the NAC gene family of night lily has not yet been analyzed systematically to date. Methods: Therefore, we conducted a genome-wide study of the HcNAC gene family and identified a total of 113 HcNAC members from the Hemerocallis citrina genome. Results: We found that 113 HcNAC genes were unevenly distributed on 11 chromosomes. Phylogenetic analysis showed that they could be categorized into 16 instinct subgroups. Proteins clustering together exhibited similar conserved motifs and intron-exon structures. Collinearity analysis indicated that segmental and tandem duplication might contribute to the great expansion of the NAC gene family in night lily, whose relationship was closer with rice than Arabidopsis. Additionally, tissue-specific pattern analysis indicated that most HcNAC genes had relatively higher expression abundances in roots. RNA-Seq along with RT-qPCR results jointly showedHcNACgenesexpresseddifferentlyunder drought andsalinity stresses. Interestingly, HcNAC35 was overexpressed in watermelon, and the stress resilience of transgenic lines was much higher than that of wild-type watermelon, which revealed its wide participation in abiotic stress response. Conclusion: In conclusion, our findings provide a new prospect for investigating the biological roles of NAC genes in night lily. [ABSTRACT FROM AUTHOR]

Vitamin C, also referred to as ascorbic acid (AsA), is recognized for its capacity to cure and avert scurvy, and it is crucial for regular human growth and development. In various crops, AsA participates in stress response mechanisms mediated by abscisic acid and has been discovered to have a crucial function in the morphogenesis, growth, development, and production of male gametes in plants. GDP-D-mannose 3′,5′-epimerase (GME) is essential in the synthesis of vitamin C. Our research identified 91, 83, 51, and 46 genes, respectively, found in G. barbadense (GbGMEs), G. hirsutum (GhGMEs), G. arboretum (GaGMEs), and G. raimondii (GrGMEs). Plants resulting from VIGS infection with GhGME31D clearly showed yellowing, water loss and wilting of leaves and black spots on stems. Measurement of MDA and AsA levels indicated that the plants were more damaged. This indicates that AsA has a substantial impact on plant growth and development. [ABSTRACT FROM AUTHOR]

AbstractExcessive boron (B) levels in soil can lead to toxicity in plants, impacting their growth and productivity. Effective strategies to reduce B uptake are important for improving crop performance in contaminated soils. This experiment aimed to investigate the effects of chicken manure incineration ash (CMA) and triple superphosphate (TSP) on B uptake in barley plants grown in B-contaminated soil. Before the experiment, the chemical composition and molecular structure of CMA were analyzed using XRF, XRD and SEM. The soil was contaminated with 15 mg kg−1 of B, and both TSP and CMA were applied at rates of 40, 80, and 160 mg kg−1 of phosphorus (P). Neither P source had a significant impact on plant dry weight. However, increasing doses of applied TSP and CMA increased plant P concentration while significantly decreasing B concentration. Particularly with CMA applied at 160 mg kg−1 P dose, plant B concentration decreased to the lowest level of 194 mg kg−1. Increasing P doses led to a slight decrease in plant silicon (Si) concentration. The pH of soil samples taken after the experiment slightly increased with CMA treatments compared to TSP. The available P concentration in soils increased with increasing P doses. The available B concentration decreased with increasing P doses, especially reducing to the lowest level of 2.52 mg kg−1 in soils with a 40 mg kg−1 P, CMA. In conclusion, in addition to the effect of P, the molecular structure of P is also important in reducing B uptake in barley. [ABSTRACT FROM AUTHOR]

Background: Brassica juncea(L.) Czern is an important oilseed crop affected by various abiotic stresses like drought, heat, and salt. These stresses have detrimental effects on the crop's overall growth, development and yield. Various Transcription factors (TFs) are involved in regulation of plant stress response by modulating expression of stress-responsive genes. The myeloblastosis (MYB) TFs is one of the largest families of TFs associated with various developmental and biological processes such as plant growth, secondary metabolism, stress response etc. However, MYB TFs and their regulation by non-coding RNAs (ncRNAs) in response to stress have not been studied in B. juncea. Thus, we performed a detailed study on the MYB TF family and their interactions with miRNAs and Long non coding RNAs. Results: Computational investigation of genome and proteome data presented a comprehensive picture of the MYB genes and their protein architecture, including intron-exon organisation, conserved motif analysis, R2R3 MYB DNA-binding domains analysis, sub-cellular localization, protein-protein interaction and chromosomal locations. Phylogenetically, BjuMYBs were further classified into different subclades on the basis of topology and classification in Arabidopsis. A total of 751 MYBs were identified in B. juncea corresponding to 297 1R-BjuMYBs, 440 R2R3-BjuMYBs, 12 3R-BjuMYBs, and 2 4R-BjuMYBs types. We validated the transcriptional profiles of nine selected BjuMYBs under drought stress through RT-qPCR. Promoter analysis indicated the presence of drought-responsive cis-regulatory components. Additionally, the miRNA-MYB TF interactions was also studied, and most of the microRNAs (miRNAs) that target BjuMYBs were involved in abiotic stress response and developmental processes. Regulatory network analysis and expression patterns of lncRNA-miRNA-MYB indicated that selected long non-coding RNAs (lncRNAs) acted as strong endogenous target mimics (eTMs) of the miRNAs regulated expression of BjuMYBs under drought stress. Conclusions: The present study has established preliminary groundwork of MYB TFs and their interaction with ncRNAs in B. juncea and it will help in developing drought- tolerant Brassica crops. [ABSTRACT FROM AUTHOR]

Changing climate imposes abiotic stress factors, including salinity, flood, drought, high and low temperature, and light as well as heavy metals on medicinal plants. Plants respond to stress in terms of growth and biosynthesis of metabolites. The rhizomatous genus Curcuma has been extensively used in traditional or folk medicine worldwide and its therapeutic potential relies on its phyto-constituents. A discrete array of literature depicts negative effects on growth and alterations in yield of secondary metabolites under abiotic stress. However, one complete and precise document on the response of Curcuma spp. towards abiotic stress and their molecular mechanism is lacking. Hence, this review has been prepared by pulling together the published information on the abiotic stress response as well as the future research prospects on the Curcuma spp. along with other related rhizomatous plants of the family Zingiberaceae, to obtain prospective clues on possible responses of these medicinally potential species in the verge of changing climate. We have also highlighted the stress mitigation strategies employed by these plants in the light of available literature and by comparing with information on related species of Zingiberaceae family. We have focused on the urgency of multiomics approaches to find out the genetic and biochemical strategies of Curcuma spp. to cope with stress as well as emphasized for conservation of rare and endangered species of Curcuma. This review will be helpful for plant physiologists, farmers, pharmaceutical industries, and policy makers, to implement better plans and policies regarding uninterrupted commercial yield of Curcuma secondary metabolites in changing climate. [ABSTRACT FROM AUTHOR]

Practical Application The effects of different doses of UV‐C irradiation (0, 0.5, 1.0, 2.0, and 4.0 kJ m−2) on the quality and antioxidant capacity of peach fruit were examined. Results showed that irradiation at 2.0 kJ m−2 led to higher firmness and total soluble solids, as well as lower weight loss and decay index. Additionally, peach fruits irradiated with 2.0 kJ m−2 UV‐C exhibited increased production of reactive oxygen species, which in turn stimulated the synthesis of total phenolics and total flavonoids and enhanced the activities of superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase. Overall, the best abiotic stress effect was observed with 2.0 kJ m−2 UV‐C irradiation, resulting in improved shelf quality and increased antioxidant capacity of peach fruits during storage.This study provides a theoretical basis for the application of UV‐C irradiation in peach fruit preservation. [ABSTRACT FROM AUTHOR]

The impact of chronic radiation exposure on phytohormone content and expression of phytohormone- and stress-related genes of Scots pine in the zone affected by the Chernobyl accident was studied. Needle samples were collected from three plots with contrasting levels of radioactive contamination in the Polesye State Radiation-Ecological Reserve, Republic of Belarus, and two reference plots in the Kozeluzhsky forest in June 2022. The experimental plots were located within the artificial plantations of Scots pine established in 1982, before the accident in 1986. The activity of radionuclides 137Cs, 90Sr, 241Am, 238Pu, and 239+240Pu in soil and needles ensured dose rates ranging from 3.3 to 87 mGy × year−1, while at the reference plots, the range was 0.7‒0.8 mGy × year−1. Concentrations of plant hormones, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), zeatin, and abscisic acid (ABA) in needles were evaluated using high-performance liquid chromatography (HPLC). We demonstrate that chronic radiation exposure is a significant stress factor that affects both phytohormonal balance and the expression of some important phytohormone- and stress-related genes. We found a tendency toward decreased ABA and auxin concentrations in trees from plots contaminated with radionuclides. The ratio (IAA + IBA + zeatin)/ABA was drastically raised at the most contaminated plots Masany and Kulazhin, reflecting the functional rearrangements of cellular metabolism that ensure plant adaptation under chronic radiation exposure. Changes in gene expression indicated modulation of ABA and Ca2+ signalling pathways, decreased potential of zeatin biosynthesis, and activation of heat shock proteins biosynthesis. [ABSTRACT FROM AUTHOR]

The demand for crops production continues to intensify with the rapid increase in population. Agricultural crops continue to encounter abiotic and biotic stresses, which can substantially hamper their productivity. Numerous strategies have been focused to tackle the abiotic and biotic stress factors in various plants. Nanotechnology has displayed great potential to minimize the phytotoxic impacts of these environmental constraints. Copper (Cu)-based nanoparticles (NPs) have displayed beneficial effects on plant growth and stress tolerance. Cu-based NPs alone or in combination with plant growth hormones or microorganisms have been documented to induce plant tolerance and mitigate abiotic or biotic stresses in different plants. In this review, we have comprehensively discussed the uptake and translocation of Cu-based NPs in plants, and beneficial roles in improving the plant growth and development at various growth stages. Moreover, we have discussed how Cu-based NPs mechanistically modulate the physiological, biochemical, metabolic, cellular, and metabolic functions to enhance plant tolerance against both biotic (viruses, bacterial and fungal diseases, etc.) and abiotic stresses (heavy metals or metalloids, salt, and drought stress, etc.). We elucidated recent advancements, knowledge gaps, and recommendations for future research. This review would help plant and soil scientists to adapt Cu-based novel strategies such as nanofertilizers and nanopesticides to detoxify the abiotic or biotic stresses. These outcomes may contribute to the promotion of healthy food production and food security, thus providing new avenues for sustainable agriculture production. [ABSTRACT FROM AUTHOR]

Maize is one of the most successful crops in utilizing heterosis which significantly improves maize stresses resistance and yield. Drought is a destructive abiotic stress that significantly reduces crop yield, particularly in maize. Drought stress and rewatering frequently occur during the growth and development of maize; however, themolecular mechanisms of heterosis under drought stress and re-watering have rarely been systematically investigated. Zhengdan7137 and Zhengdan7153 are two maize hybrid varieties with robust heterosis, and separately belongs to the SS×NSS and Reid×Tangsipingtou heterotic groups. 54 transcriptomes of these two hybrids and their parental inbred lines were analyzed under well-watering (WW), waterdeficit (WD), and re-watering (RW) conditions using RNA-Seq. In this study, we identified 3,411 conserved drought response genes (CDRGs) and 3,133 conserved re-watering response genes (CRRGs) between Zhengdan7137 and Zhengdan7153. When comparing CDRGs and CRRGs to overdominance and underdominance genes, we identified 303 and 252 conservative drought response overdominance genes (DODGs) and underdominance genes (DUDGs), respectively, and 165 and 267 conservative re-watering response overdominance genes (RODGs) and underdominance genes (RUDGs), respectively. DODGs are involved in stress response-related processes, such as L-phenylalanine metabolism, carbohydrate metabolism, and heat response, whereas DUDGs are associated with glucose metabolism, pentose-phosphate shunt, and starch metabolism. RODGs and RUDGs contribute to the recovery of hybrids from drought stress by upregulating cell propagation and photosynthesis processes, and repressing stress response processes, respectively. It indicated overdominant and underdominant genes conservatively contributed to hybrid heterosis under drought stress. These results deepen our understanding of the molecular mechanisms of drought resistance, uncover conservative molecular mechanisms of heterosis under drought stress and re-watering, and provide potential targets for improving drought resistance in maize. [ABSTRACT FROM AUTHOR]

Plant architecture determines canopy coverage, photosynthetic efficiency, and ultimately productivity in soybean (Glycine max). Optimizing plant architecture is a major goal of breeders to develop high yield soybean varieties. Over the past few decades, the yield per unit area of soybean has not changed significantly; however, rice and wheat breeders have succeeded in achieving high yields by generating semi-dwarf varieties. Semi-dwarf crops have the potential to ensure yield stability in high-density planting environments because they can significantly improve responses to fertilizer input, lodging resistance, and enhance resistance to various abiotic and biotic stresses. Soybean has a unique plant architecture, with leaves, inflorescences, and pods growing at each node; internode number greatly affects the final yield. Therefore, producing highyielding soybean plants with an ideal architecture requires the coordination of effective node formation, effective internode formation, and branching. Dozens of quantitative trait loci (QTLs) controlling plant architecture have been identified in soybean, but only a few genes that control this trait have been cloned and characterized. Here, we review recent progress in understanding the genetic basis of soybean plant architecture. We provide our views and perspectives on how to breed new high-yielding soybean varieties. [ABSTRACT FROM AUTHOR]

The DNA-binding with one finger (Dof) gene family is a class of plant-specific transcription factors involved in diverse biological processes, including response to biotic and abiotic stresses. Members of this family have been reported in the cultivated potato Solanum tuberosum, but clues to the roles of several Dof genes are still lacking. Potato wild relatives represent a genetic reservoir for breeding as they could provide useful alleles for adaptation to the environment and tolerance to biotic and abiotic stresses. We performed an in silico analysis to identify genes belonging to the Dof family in the wild potato S. commersonii, confirming that the identified Dof genes can be grouped in four classes (A, B, C, D), as reported for cultivated potato. A special focus was dedicated to Cycling Dof Factors (CDFs), which play a crucial role in plant responses to abiotic stresses. Analysis of available RNA-seq data confirmed CDF genes as regulated by stresses and often in a tissue specific manner. To ascertain their involvement in the stress response, S. tuberosum and S. commersonii plantlets growing in vitro were subjected to salt stress (80mM NaCl) for short (2 days) and prolonged (7 days) times. Analysis of phenotypic traits and qRT-PCR expression profiles of target CDF genes in aerial and root tissues showed differences between the two species. In addition, after saline treatment, changes in total phenols, proline, and malondialdehyde suggested a diverse perception of saline stress in S. commersonii vs. S. tuberosum. Overall, this study provided useful clues to the involvement of CDF genes in salt response and promoted the identification of potential candidate genes for further functional studies. [ABSTRACT FROM AUTHOR]

In photoperiod-sensitive plants, the CO-like gene (CONSTANS-like, COL) has a crucial function in regulating the timing of flowering. The blooming period in foxtail millet is greatly influenced by the duration of daylight; however, there is a scarcity of data regarding the molecular properties of the COL genes in the foxtail millet. In this study, we conducted a comprehensive analysis of the COL gene family in foxtail millet at the genome-wide level. We identified 11 SiCOL genes and performed gene structure analysis, which showed pronounced variation in gene length and intron number among the genes. The examination of COL proteins in foxtail millet and other plant species using phylogenetic analysis revealed that they could be clustered into three distinct groups. Cis-element analysis identified elements related to light-responsiveness, hormones, and abiotic stress in the promoter region of the SiCOL gene. Furthermore, tissue-specific expression analysis showed widespread expression of all 11 SiCOL genes in various foxtail millet tissues and organs, particularly in leaves and panicles. Collinearity analysis identified 14 syntenic gene pairs in both foxtail millet and rice. The results also revealed diurnal oscillations in the transcription levels of SiCOL genes under different light conditions. Moreover, among the 11 genes, SiCO, SiCOL1, and SiCOL6 expression levels were negatively correlated with flowering time variation in two foxtail cultivars. Additionally, upon constructing a network of predicted molecular interactions, FLOWER LOCUS-like (FTL) and Phytochromea A (PHY A) were suggested to potentially interact with SiCO, SiCOL1, and SiCOL6. SiCO, SiCOL1, and SiCOL6 have the potential for flowering and heading in foxtail millet. This research enhances our comprehension of the role and control of the SiCOL gene family constituents in foxtail millet, establishing a basis for future investigations. [ABSTRACT FROM AUTHOR]

Heat shock protein 70 (HSP70) is one kind of molecular chaperones which are widely found in organisms, and its members are highly conserved among each other, with important roles in plant growth and development. In this study, 56 HSP70 genes were identified from the apple genome database. Analysis of gene duplication events showed that tandem and segmental duplication events play an important role in promoting the amplification of the MdHSP70 gene family. Collinearity analysis showed that HSP70 family members of apple were more closely related to HSP70 family members of Arabidopsis, tomato and soybean. The promoter region of the apple HSP70 genes contains a large number of cis-acting elements in response to hormones and stress. Tissue-specific expression analysis showed that some of the genes were associated with various stages of the apple growth process. Codon preference analysis showed small differences between codon bases 1 and 3 in the apple HSP70 genome, and the codon base composition had a small effect on codon usage preference. The multiple expression patterns of the MdHSP70 gene suggested that MdHSP70 gene members play important roles in growth and development and in response to hormonal and abiotic stresses. The yeast two-hybrid (Y2H) demonstrated that MdHSP70-53 interacts with MdDVH24_032563. The qRT-PCR analysis showed that most MdHSP70 members' hormonal and abiotic stresses (MdHSP70-6, MdHSP70-26 and MdHSP70-45) appeared to be highly expressed. To further elucidate the function of MdHSP70 (6, 26, 45), we introduced them into tobacco to confirm subcellular locations and noted that these genes are located in the cytoplasm and cell membrane. This study serves as a theoretical basis for further studies of the MdHSP70 gene and helps to further investigate the functional characterization of MdHSP70 gene. [ABSTRACT FROM AUTHOR]

Summary The nonphototrophic hypocotyl 3 (NPH3) domain is plant specific and of unknown function. It is nearly always attached to an N‐terminal BTB domain and a largely unstructured C‐terminal region. Recent reports revealed NPH3‐domain GTPase activity and connection to intracellular trafficking, condensate formation, membrane attachment of the C‐terminal region for some NPH3‐domain proteins and, at the physiological level, drought‐related function for at least one NPH3‐domain protein. We integrate these new ideas of NPH3‐domain protein function into two, nonexclusive, working models: the ‘traffic director’ model, whereby NPH3‐domain proteins regulate intracellular trafficking and, the ‘hitchhiker’ model whereby NPH3‐domain proteins ride the trafficking system to find ubiquitination targets. Determining which model best applies to uncharacterized NPH3‐domain proteins will contribute to understanding intracellular trafficking and environmental responses. [ABSTRACT FROM AUTHOR]

Lentil (Lens culinaris Medikus) is a nutrient-rich, cool-season food legume that is high in protein, prebiotic carbohydrates, vitamins, and minerals. It is a staple food in many parts of the world, but crop performance is threatened by climate change, where increased temperatures and less predictable precipitation can reduce yield and nutritional quality. One mechanism that many plant species use to mitigate heat and drought stress is the production of disaccharides, oligosaccharides and sugar alcohols, collectively referred to as low molecular weight carbohydrates (LMWCs). Recent evidence indicates that lentil may also employ this mechanism - especially raffinose family oligosaccharides and sugar alcohols - and that these may be suitable targets for genomic-assisted breeding to improve crop tolerance to heat and drought stress. While the genes responsible for LMWC biosynthesis in lentil have not been fully elucidated, single nucleotide polymorphisms and putative genes underlying biosynthesis of LMWCs have been identified. Yet, more work is needed to confirm gene identity, function, and response to abiotic stress. This review i) summarizes the diverse evidence for how LMWCs are utilized to improve abiotic stress tolerance, ii) highlights current knowledge of genes that control LMWC biosynthesis in lentil, and iii) explores how LMWCs can be targeted using diverse genomic resources and markers to accelerate lentil breeding efforts for improved stress tolerance. [ABSTRACT FROM AUTHOR]

The glyoxalase pathway, consisting of glyoxalase I (GLYI) and glyoxalase II (GLYII), is an enzymatic system that converts cytotoxic methylglyoxal to non-toxic S-D-lactoylglutathione. Although the GLY gene family has been analyzed in Arabidopsis, rice, grape, cabbage, and soybean, cucumber studies are lacking. Here, we analyzed the cucumber GLY gene family, identifying 13 CsGLYI and 2 CsGLYII genes. Furthermore, we investigated the physicochemical properties, phylogenetic relationships, chromosomal localization and colinearity, gene structure, conserved motifs, cis-regulatory elements, and protein–protein interaction networks of the CsGLY family. They were primarily localized in the cytoplasm, chloroplasts, and mitochondria, with a minor presence in the nucleus. The classification of CsGLYI and CsGLYII genes into five classes closely resembled the homologous genes in Arabidopsis and soybean. Additionally, hormone-responsive elements dominated the promoter region of GLY genes, alongside light- and stress-responsive elements. The predicted interaction proteins of CsGLYIs and CsGLYIIs exerted a significant role in cellular respiration, amino acid synthesis, and metabolism, as well as methylglyoxal catabolism. In addition, the expression profiles of GLY genes were distinct in different tissues of cucumber as well as under diverse abiotic stresses. This study is conducive to the further exploration of the functional diversity among glyoxalase genes and the mechanisms of stress responses in cucumber. [ABSTRACT FROM AUTHOR]

Serine/arginine-rich (SR) proteins mostly function as splicing factors for pre-mRNA splicing in spliceosomes and play critical roles in plant development and adaptation to environments. However, detailed study about SR proteins in legume plants is still lacking. In this report, we performed a genome-wide investigation of SR protein genes in wild soybean (Glycine soja) and identified a total of 31 GsSR genes from the wild soybean genome. The analyses of chromosome location and synteny show that the GsSRs are unevenly distributed on 15 chromosomes and are mainly under the purifying selection. The GsSR proteins can be phylogenetically classified into six sub-families and are conserved in evolution. Prediction of protein phosphorylation sites indicates that GsSR proteins are highly phosphorylated proteins. The protein–protein interaction network implies that there exist numerous interactions between GsSR proteins. We experimentally confirmed their physical interactions with the representative SR proteins of spliceosome-associated components such as U1-70K or U2AF35 by yeast two-hybrid assays. In addition, we identified various stress-/hormone-responsive cis-acting elements in the promoter regions of these GsSR genes and verified their expression patterns by RT-qPCR analyses. The results show most GsSR genes are highly expressed in root and stem tissues and are responsive to salt and alkali stresses. Splicing analysis showed that the splicing patterns of GsSRs were in a tissue- and stress-dependent manner. Overall, these results will help us to further investigate the biological functions of leguminous plant SR proteins and shed new light on uncovering the regulatory mechanisms of plant SR proteins in growth, development, and stress responses. [ABSTRACT FROM AUTHOR]

Phoebe bournei is a second-class endangered and protected species unique to China, and it holds significant ecological and economic value. DNA binding one zinc finger (Dof) transcription factors are plant-specific regulators. Numerous studies have demonstrated that Dof genes are involved in plant growth, development and responses to abiotic stress. In this study, we identified and analyzed 34 PbDof gene members at the whole-genome level. The results indicated that the 34 PbDof genes were unevenly distributed across 12 chromosomes. We utilized the Dof genes from Arabidopsis thaliana and P. bournei to construct a phylogenetic tree and categorized these genes into eight subgroups. In the collinearity analysis, there were 16 homologous gene pairs between AtDof and PbDof and nine homologous gene pairs between ZmDof and PbDof. We conducted a cis-acting element analysis and found that cis-acting elements involved in light response were the most abundant in PbDof genes. Through SSR site prediction, we analyzed that the evolution level of Dof genes is low. Additionally, we assessed the expression profiles of eight PbDof genes under high temperature, drought, and light stress using qRT-PCR. In particular, PbDof08 and PbDof16 are significantly upregulated under the three stresses. This study provides foundational information for PbDof genes and offers new insights for further research on the mechanism of Dof transcription factors responding to stress, as well as the adaptation of P. bournei to environmental changes. [ABSTRACT FROM AUTHOR]

The Domain of Unknown Function 506 (DUF506) belongs to the PD-(D/E) XK nuclease superfamily and has been reported to play critical roles in growth and development as well as responses to abiotic stresses. However, the function of DUF506 genes in Brassica rapa (B. rapa) remains unclear. In this study, a total of 18 BrDUF506 genes were identified and randomly distributed across eight chromosomes, categorized into four subfamilies. Analyzing their promoter sequences has uncovered various stress-responsive elements, such as those for drought, methyl jasmonate (MeJA), and abscisic acid (ABA). Bra000098 and Bra017099 exhibit significantly enhanced expression in response to heat and drought stress. Protein interaction predictions indicate that Bra000098 homolog, At2g38820, is interacting with ERF012 and PUB48 and is involved in abiotic stress regulation. Furthermore, gene expression profiling has identified Bra026262 with a high expression level in flowers and significantly decreased in female sterile mutants. Protein interaction prediction further revealed that its homolog, At4g32480, interacts with MYB and AGL proteins, suggesting the potential roles in female gametophyte development. The current study enhances our understanding of the functional roles of BrDUF506s, providing significant insights that are valuable in investigating sexual reproduction and abiotic stress responses in B. rapa. [ABSTRACT FROM AUTHOR]

Peanut (Arachis hypogaea L.) is one of the most important oil and food legume crops worldwide. ASR (abscisic acid, stress, ripening) plays extremely important roles in plant growth and development, fruit ripening, pollen development, and stress. Here, six ASR genes were identified in peanut. Structural and conserved motif analyses were performed to identify common ABA/WDS structural domains. The vast majority of ASR genes encoded acidic proteins, all of which are hydrophilic proteins and localized on mitochondria and nucleus, respectively. The cis-element analysis revealed that some cis-regulatory elements were related to peanut growth and development, hormone, and stress response. Under normal growth conditions, AhASR4 and AhASR5 were expressed in all tissues of peanut plants. Quantitative real-time PCR (qRT-PCR) results indicated that peanut ASR genes exhibited complex expression patterns in response to abiotic stress. Notably, under drought and cadmium (Cd) stress, the expression levels of AhASR4 and AhASR5 were significantly upregulated, suggesting that these genes may play a crucial role in the peanut plant's resistance to such stressors. These results provide a theoretical basis for studying the evolution, expression, and function of the peanut ASR gene family and will provide valuable information in the identification and screening of genes for peanut stress tolerance breeding. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m6A) is an abundant and pervasive post-transcriptional modification in eukaryotic mRNAs. AlkB homolog (ALKBH) proteins play crucial roles in RNA metabolism and translation, participating in m6A methylation modification to regulate plant development. However, no comprehensive investigations have been conducted on ALKBH in potato. Here, 11 StALKBH family genes were identified in potato and renamed according to BLASTP and phylogenetic analyses following the Arabidopsis genome. The characteristics, sequence structures, motif compositions, phylogenetics, chromosomal locations, synteny, and promoter cis-acting element predictions were analyzed, revealing distinct evolutionary relationships between potato and other species (tomato and Arabidopsis). Homologous proteins were classified into seven groups depending on similar conserved domains, which implies that they possess a potentially comparable function. Moreover, the StALKBHs were ubiquitous, and their expression was examined in the various tissues of a whole potato, in which the StALKBH genes, except for StALKBH2, were most highly expressed in the stolon and flower. Multiple hormone and stress-response elements were found to be located in the promoters of the StALKBH genes. Further qRT-PCR results suggest that they may be significantly upregulated in response to phytohormones and abiotic stress (except for cold), and the expression of most of the StALKBH genes exhibited positively modulated trends. Overall, this study is the first to report a genome-wide assessment of the ALKBH family in potato, providing valuable insights into candidate gene selection and facilitating in-depth functional analyses of ALKBH-mediated m6A methylation mechanisms in potato. [ABSTRACT FROM AUTHOR]

SUMMARY: Lipid remodeling plays a critical role in plant response to abiotic stress and metabolic perturbations. Key steps in this process involve modifications of phosphatidylcholine (PC) acyl chains mediated by lysophosphatidylcholine: acyl‐CoA acyltransferases (LPCATs) and phosphatidylcholine: diacylglycerol cholinephosphotransferase (ROD1). To assess their importance in lipid homeostasis, we took advantage of the trigalactosyldiacylglycerol1 (tgd1) mutant that exhibits marked increases in fatty acid synthesis and fatty acid flux through PC due to a block in inter‐organelle lipid trafficking. Here, we showed that the increased fatty acid synthesis in tgd1 is due to posttranslational activation of the plastidic acetyl‐coenzyme A carboxylase. Genetic analysis showed that knockout of LPCAT1 and 2 resulted in a lethal phenotype in tgd1. In addition, plants homozygous for lpcat2 and heterozygous for lpcat1 in the tgd1 background showed reduced levels of PC and triacylglycerols (TAG) and alterations in their fatty acid profiles. We further showed that disruption of ROD1 in tgd1 resulted in changes in fatty acid composition of PC and TAG, decreased leaf TAG content and reduced seedling growth. Together, our results reveal a critical role of LPCATs and ROD1 in maintaining cellular lipid homeostasis under conditions, in which fatty acid production largely exceeds the cellular demand for membrane lipid synthesis. Significance Statement: Characterization of tgd1 mutants reveals a critical role of PC remodeling mediated by LPCATs and ROD1 in maintaining cellular lipid homeostasis. [ABSTRACT FROM AUTHOR]

SUMMARY E2 ubiquitin‐conjugating enzymes play a crucial role in the ubiquitination process by catalyzing ubiquitin transfer. Although the function of ubiquitin‐protein ligases (E3s) in plants response to diverse abiotic stress by targeting specific substrates has been well studied, the involvement of E2s in environmental responses and their downstream targets are not well understood. In this study, we demonstrated that the E2 ubiquitin‐conjugating enzyme 18 (UBC18) influences the stability of FREE1 to modulate iron deficiency stress. UBC18 affects the ubiquitination of FREE1 and promotes its degradation, and overexpression of UBC18 decreases plants’ sensitivity to iron deficiency by reducing FREE1 level, whereas the ubc18 mutant exhibits sensitivity due to elevated FREE1 accumulation. This study also identified that lysine residues K227, K295, K315, and K540 are required for FREE1 ubiquitination and stability regulation. Mutating these lysine residues in FREE1 resulted in plants’ sensitivity to iron starvation. Taken together, our findings shed light on the mechanism of UBC18 in responding to iron deficiency stress by modulating the abundance of FREE1, and further elucidate the role of ubiquitination sites in FREE1 stability regulation and the plant iron deficiency response. [ABSTRACT FROM AUTHOR]

ABSTRACT The phospholipase Ds (PLDs) are crucial for cellular signalling and play roles in plant abiotic stress response. In this study, we identified 12 PLD genes from the genome data of perennial ryegrass (Lolium perenne), which is widely used as forage and turfgrass. Among them, LpPLDδ3 was significantly repressed by ABA treatment, and induced by drought stress and heat stress treatments. The ectopic overexpression (OE) of LpPLDδ3 in Arabidopsis enhanced plant tolerance to osmotic and heat stress as demonstrated by an increased survival rate and reduced malondialdehyde (MDA) accumulation and electrolyte leakage (EL). Arabidopsis endogenous ABA RESPONSIVE ELEMENT BINDING FACTORs (ABFs) and heat stress responsive genes were elevated in LpPLDδ3 OE lines under osmotic and heat stress treatments. Additionally, overexpression of LpPLDδ3 in perennial ryegrass protoplasts could increase heat stress tolerance and elevate expression level of heat stress responsive genes. Moreover, LpABF2 and LpABF4 depressed the LpPLDδ3 expression by directly binding to its ABRE core‐binding motif of promoter region. In summary, LpPLDδ3 was repressed by LpABF2 and LpABF4 and positively involved in perennial ryegrass osmotic and heat stress responses. [ABSTRACT FROM AUTHOR]

Autophagy is a preserved process in eukaryotes that allows large material degeneration and nutrient recovery via vacuoles or lysosomes in cytoplasm. Autophagy starts from the moment of induction during the formation of a phagophore. Degradation may occur in the autophagosomes even without fusion with lysosome or vacuole, particularly in microautophagosomes. This process is arbitrated by the conserved machinery of basic autophagy‐related genes (ATGs). In selective autophagy, specific materials are recruited by autophagosomes via receptors. Selective autophagy targets a vast variety of cellular components for degradation, i.e., old or damaged organelles, aggregates, and inactive or misfolded proteins. In optimal conditions, autophagy in plants ensures cellular homeostasis, proper plant growth, and fitness. Moreover, autophagy is essential during stress responses in plants and aids in survival of plants. Several biotic and abiotic stresses, i.e., pathogen infection, nutrient deficiency, plant senescence, heat stress, drought, osmotic stress, and hypoxia induce autophagy in plants. Cell death is not a stress, which induces autophagy but in contrast, sometimes it is a consequence of autophagy. In this way, autophagy plays a vital role in plant survival during harsh environmental conditions by maintaining nutrient concentration through elimination of useless cellular components. This review discussed the recent advances regarding regulatory functions of autophagy under normal and stressful conditions in plants and suggests future prospects in mitigating climate change. Autophagy in plants offers a viable way to increase plant resilience to climate change by increasing stress tolerance and nutrient usage efficiency. [ABSTRACT FROM AUTHOR]

Salinity represents a considerable environmental risk, exerting deleterious effects on horticultural crops. Nanotechnology has recently emerged as a promising avenue for enhancing plant tolerance to abiotic stress. Among nanoparticles, cerium oxide nanoparticles (CeO2 NPs) have been demonstrated to mitigate certain stress effects, including salinity. In the present study, the impact of CeO2 NPs (0, 25, and 100 mg L−1) on various morphological traits, photosynthetic pigments, biochemical parameters, and the essential oil profile of spearmint plants under moderate (50 mM NaCl) and severe (100 mM NaCl) salinity stress conditions was examined. As expected, salinity reduced morphological parameters, including plant height, number of leaves, fresh and dry weight of leaves and shoots, as well as photosynthetic pigments, in comparison to control. Conversely, it led to an increase in the content of proline, total phenols, malondialdehyde (MDA), hydrogen peroxide (H2O2), and antioxidant enzyme activities. In terms of CeO2 NP applications, they improved the salinity tolerance of spearmint plants by increasing chlorophyll and carotenoid content, enhancing antioxidant enzyme activities, and lowering MDA and H2O2 levels. However, CeO2 NPs at 100 mg L−1 had adverse effects on certain physiological parameters, highlighting the need for careful consideration of the applied concentration of CeO2 NPs. Considering the response of essential oil compounds, combination of salinity stress and CeO2 treatments led to an increase in the concentrations of L-menthone, pulegone, and 1,8-cineole, which are the predominant compounds in spearmint essential oil. In summary, foliar application of CeO2 NPs strengthened the resilience of spearmint plants against salinity stress, offering new insights into the potential use of CeO2 NP treatments to enhance crop stress tolerance. [ABSTRACT FROM AUTHOR]

Mitogen-activated protein kinase (MAPK/MPK) cascades are pivotal and highly conserved signaling modules widely distributed in eukaryotes; they play essential roles in plant growth and development, as well as biotic and abiotic stress responses. With the development of sequencing technology, the complete genome assembly of rice without gaps, T2T (Telomere-to-Telomere)—NIP (version AGIS-1.0), has recently been released. In this study, we used bioinformatic approaches to identify and analyze the rice MPK kinases (MKKs) based on the complete genome. A total of seven OsMKKs were identified, and their physical and chemical properties, chromosome localization, gene structure, subcellular localization, phylogeny, family evolution, and cis-acting elements were evaluated. OsMKKs can be divided into four subgroups based on phylogenetic relationships, and the family members located in the same evolutionary branch have relatively similar gene structures and conserved domains. Quantitative real-time PCR (qRT-PCR) revealed that all OsMKKs were highly expressed in rice seedling leaves. The expression levels of all OsMKKs were more or less altered under exogenous hormone and abiotic stress treatments, with OsMKK1, OsMKK6, and OsMKK3 being induced under almost all treatments, while the expression of OsMKK4 and OsMKK10-2 was repressed under salt and drought treatments and IAA treatment, respectively. In this study, we also summarized the recent progress in rice MPK cascades, highlighted their diverse functions, and outlined the potential MPK signaling network, facilitating further studies on OsMKK genes and rice MPK cascades. [ABSTRACT FROM AUTHOR]

Plants are able to perceive diverse environmental factors and form an appropriate systemic functional response. Systemic responses are induced by stimulus-specific long-distance signals that carry information about the stimulus. Variation potential is proposed as a candidate for the role of such a signal. Here, we focus on the mechanisms that determine the specificity of the variation potential under the action of different local stimuli. Local stimuli such as heating, burning and wounding cause variation potential, the parameters of which differ depending on the type of stimulus. It was found that the stimulus-specific features of the hydraulic signal monitored by changes in leaf thickness and variation potential, such as a greater amplitude upon heating and burning and a significant amplitude decrement upon burning and wounding, were similar. The main features of these signals are the greater amplitude upon heating and burning, and a significant amplitude decrement upon burning and wounding. Together with the temporal correspondence of signal propagation, this evidence indicates a role for the hydraulic signal in the induction of stimulus-specific variation potential. Experiments using mechanosensitive channel inhibitors have demonstrated that the hydraulic signal contributes more to the induction of the variation potential in the case of rapidly growing stimuli, such as burning and wounding, than in the case of gradual heating. For thermal stimuli (gradual heating and burning), a greater contribution, compared to wounding, of the chemical signal related to reactive oxygen species to the induction of the variation potential was demonstrated. Thus, the specificity of the parameters of the variation potential is determined by the different contributions of hydraulic and chemical signals. [ABSTRACT FROM AUTHOR]

The γ-aminobutyric acid (GABA) is a widely distributed neurotransmitter in living organisms, known for its inhibitory role in animals. GABA exerts calming effects on the mind, lowers blood pressure in animals, and enhances stress resistance during the growth and development of plants. Enhancing GABA content in plants has become a focal point of current research. In plants, GABA is synthesized through two metabolic pathways, the GABA shunt and the polyamine degradation pathway, with the GABA shunt being the primary route. Extensive studies have investigated the regulatory mechanisms governing GABA synthesis. At the genetic level, GABA production and degradation can be modulated by gene overexpression, signaling molecule-induced expression, transcription factor regulation, and RNA interference. Additionally, at the level of transporter proteins, increased activity of GABA transporters and proline transporters enhances the transport of glutamate and GABA. The activity of glutamate decarboxylase, a key enzyme in GABA synthesis, along with various external factors, also influences GABA synthesis. This paper summarizes the biological functions, metabolic pathways, and regulatory mechanisms of GABA, providing a theoretical foundation for further research on GABA in plants. [ABSTRACT FROM AUTHOR]

Introduction: Melatonin, a tryptophan-derived indoleamine metabolite with important roles in plant growth and defense, has recently been regarded as a new plant hormone. Maize is one of the most important cereal crops in the world. Although the melatonin receptor gene, ZmPMTR1, has already been identified, the genetic basis of melatonin biosynthesis in maize has still not been elucidated. Serotonin N-acetyltransferase (SNAT) is the enzyme that converts serotonin to N-acetylserotonin (NAS) or 5-methoxytryptamine (5MT) to melatonin in Arabidopsis and rice, but no SNAT encoding gene has been identified yet in maize. Methods: The bioinformatics analysis was used to identify maize SNAT genes and the enzyme activity of the recombinant proteins was determined through in vitro assay. The expression levels of ZmSNAT1 and ZmSNAT3 under drought and heat stresses were revealed by public RNA-seq datasets and qRT-PCR analysis. Results: We first identified three maize SNAT genes, ZmSNAT1, ZmSNAT2, and ZmSNAT3, through bioinformatics analysis, and demonstrated that ZmSNAT2 was present in only eight of the 26 cultivars analyzed. We then determined the enzyme activity of ZmSNAT1 and ZmSNAT3 using their recombinant proteins through in vitro assay. The results showed that both ZmSNAT1 and ZmSNAT3 could convert serotonin to NAS and 5-MT to melatonin. Recombinant ZmSNAT1 catalyzed serotonin into NAS with a higher catalytic activity (Km, 8.6 mM; Vmax, 4050 pmol/min/mg protein) than ZmSNAT3 (Km, 11.51 mM; Vmax, 142 pmol/min/mg protein). We further demonstrated that the 228th amino acid Tyr (Y228) was essential for the enzymatic activity of ZmSNAT1. Finally, we revealed that the expression of ZmSNAT1 and ZmSNAT3 varied among different maize cultivars and different tissues of a plant, and was responsive to drought and heat stresses. Discussion: In summary, the present study identified and characterized the first two functional SNAT genes in maize, laying the foundation for further research on melatonin biosynthesis and its regulatory role in plant growth and response to abiotic stresses. [ABSTRACT FROM AUTHOR]

Plant growth-promoting rhizobacteria colonize the rhizosphere through dynamic and intricate interactions with plants, thereby providing various benefits and contributing to plant growth. Moreover, increasing evidence suggests that plant growth-promoting rhizobacteria affect plant tolerance to abiotic stress, but the underlying molecular mechanisms remain largely unknown. In this study, we investigated the effect of Bacillus velezensis strain GH1-13 on drought stress tolerance in rice. Phenotypical analysis, including the measurement of chlorophyll content and survival rate, showed that B. velezensis GH1-13 enhances rice tolerance to drought stress. Additionally, visualizing ROS levels and quantifying the expression of ROS-scavenging genes revealed that GH1-13 treatment reduces ROS accumulation under drought stress by activating the expression of antioxidant genes. Furthermore, the GH1-13 treatment stimulated the jasmonic acid response, which is a key phytohormone that mediates plant stress tolerance. Together with the result that jasmonic acid treatment promotes the expression of antioxidant genes, these findings indicate that B. velezensis GH1-13 improves drought tolerance in rice by reducing ROS accumulation and suggest that activation of the jasmonic acid response is deeply involved in this process. [ABSTRACT FROM AUTHOR]

The tropical maize breeding for low-P tolerance and good performance under low-P stress environments can be achieved through selection based on root morphology traits at seedling stage. Here, we assessed the genotypic variation and genetic diversity of a panel of 151 tropical maize inbred lines for root and shoot seedling traits, investigated the relationship among traits and selected a set of promising inbred lines for low-P tolerance and performance. We evaluated the inbred lines at seedling stage in a greenhouse experiment under two conditions: applied P (AP) and non-applied P (NAP). A mixed model approach was used to estimate variance components and predict the genotypic values of each inbred line. The genetic diversity among inbred lines based on root and shoot traits was assessed, and correlations were estimated between tested traits under AP and NAP. Our panel of inbred lines showed huge genetic variability for all traits and presented large genetic diversity under both P conditions. Variance components due to the inbred line x P condition interaction were also highly significant (P < 0.01) for all traits. Root dry weight (RDW) was positively associated with stalk dimeter (SD), shoot dry weight (SDW) and root length, volume, and area under both P conditions. Also, the SD and SDW were associated with most root traits under AP. Based on low-P tolerance and performance indices, we selected a set of top 20 inbred lines to be used in our maize breeding program. We therefore concluded that there is a significant genetic diversity in the tropical maize inbred lines which have the genetic potential to be use in association mapping studies and also to develop improved low-P tolerant and P-efficient hybrids and maize breeding populations for low-P stress environments. [ABSTRACT FROM AUTHOR]

AbstractPseudomonas species are a versatile group of gram-negative bacteria that thrive in diverse ecological niches including soil, water, and plant environments. Their remarkable metabolic flexibility arises from their ability to utilize a plethora of compounds as carbon or energy sources, a feature that has attracted extensive scientific research. These microbial powerhouses are equipped to degrade various pollutants and toxins, thereby positioning them as valuable allies for bioremediation. This detoxification process is not only claim for ecological fame. Pseudomonas also exhibits potent biocontrol capabilities, and acts as a guard against plant pathogens. Their control strategies includes a suite of antimicrobial substances, along with an innate ability to outcompete other microbes for nutrients and stimulate plant defense. By harnessing these natural defenders, a range of Pseudomonas-based biocontrol agents have been formulated for agriculture. This approach is of growing interest for leveraging Pseudomonas strains as biofertilizers to support sustainable farming practices. These bacterial promoters enhance plant growth by boosting nutrient assimilation and by promoting robust root systems. New-generation biofertilizers can support crop yields and fortify soil vitality, thereby offering resilience to abiotic stress. This offers dual benefit of improving agricultural productivity while attenuating the harmful environmental problems caused by chemical fertilizers. Overall, the versatility of Pseudomonas species makes them a promising resource, spanning from agricultural enhancement to environmental remediation. As research accelerates, the ambition is to unlock and refine the myriad applications of these extraordinary bacteria. [ABSTRACT FROM AUTHOR]

Methylation at 5' cytosine of DNA molecule is an important epigenetic mark. It is known to play critical role in adaptation of organisms under different biotic and abiotic stressors via modulating gene expression and/or chromatin architecture. Plant populations evolved under variable climatic conditions may have evolved different epigenetic marks including DNA methylation. Here we, describe the genome-wide DNA methylation pattern under native field, F1 and F6 generation followed by their association with phenotypes, climate and global gene expression in the three Arabidopsis thaliana populations originated at different elevation ranges of Indian West Himalaya. We show that the global methyl cytosine (mC) content is more or less similar in the three populations but differ in their distribution across genome. There was an increase in differential methylation between the populations as elevation increased. The methylation divergence was the highest between the low and the high elevation populations. The high elevation populations were hypo-methylated than the low elevation population. The methylation in the genes was associated with population specific phenotypes and climate of the region. The genes which were differentially methylated as well as differentially expressed between the low and high elevation populations were mostly related to abiotic stresses. When grown under controlled condition, there was gain of differential methylation over native condition and the maximum percent changes was observed in CHH-sequence context. Further ~ 99.8% methylated cytosines were stably passed on from F1 to F6 generation. Overall, our data suggest that high elevation population is epigenetically more plastic under changing environmental condition. BackgroundArabidopsis thaliana is the model plant species and has been extensively studied to understand plants life processes. There are numerous reports on its origin, demography, evolution, epigenomes and adaptation etc. however, Indian populations of Arabidopsis thaliana evolved along wide elevation ranging from ~ 700 m amsl to ~ 3400 m amsl not explored yet. Here we, describe the genome-wide DNA methylation pattern under native field, F1 and F6 generation followed by their association with phenotypes, climate and global gene expression in the three Arabidopsis thaliana populations originated at different elevation ranges of Indian West Himalaya. Results In our study we found that total mCs percent was more or less similar in the three populations but differ in their distribution across genome. The proportion of CG-mCs was the highest, followed by CHH-mCs and CHG-mCs in all the three populations. Under native field condition the methylation divergence was more prominent between low and high elevation populations and the high elevation populations were hypo-methylated than the low elevation population. The methylation in the genes was linked to population-specific phenotypes and the regional climate. The genes that showed differential methylation and expression between low and high elevation populations were primarily associated with abiotic stress responses. When grown under controlled condition, there was gain of differential methylation compared to the native condition and the maximum percent changes was observed in CHH-sequence context. Further 99.8% methylated cytosines were stably passed on from F1 to F6 generation. Conclusions The populations of A. thaliana adapted at different climatic conditions were significantly differentially methylated both under native and controlled condition. However, the magnitude and extent of gain or loss of methylation were most significant between the low and the high elevation populations. Overall, our data suggest that high elevation population is epigenetically more plastic under changing environmental condition. [ABSTRACT FROM AUTHOR]

SUMMARY Basic helix–loop–helix (bHLH) proteins comprise one of the largest families of transcription factors in plants, which play roles in plant development, secondary metabolism, and the response to biotic/abiotic stresses. However, the roles of bHLH proteins in thermotolerance are largely unknown. Herein, we identified a heat‐inducible member of the bHLH family in lily (Lilium longiflorum), named LlbHLH87, which plays a role in thermotolerance. LlbHLH87 was rapidly induced by transient heat stress, and its encoded protein was localized to the nucleus, exhibiting transactivation activity in both yeast and plant cells. Overexpression of LlbHLH87 in Arabidopsis enhanced basal thermotolerance, while silencing of LlbHLH87 in lily reduced basal thermotolerance. Further analysis showed that LlbHLH87 bound to the promoters of HEAT STRESS TRANSCRIPTION FACTOR A2 (LlHSFA2) and ETHYLENE‐INSENSITIVE 3 (LlEIN3) to directly activate their expression. In addition, LlbHLH87 interacted with itself and with SPATULA (LlSPT) protein. LlSPT was activated by extended heat stress and its protein competed for the homologous interaction of LlbHLH87, which reduced the transactivation ability of LlbHLH87 for target genes. Compared with that observed under LlbHLH87 overexpression alone, co‐overexpression of LlbHLH87 and LlSPT reduced the basal thermotolerance of lily to sudden heat shock, but improved its thermosensitivity to prolonged heat stress treatment. Overall, our data demonstrated that LlbHLH87 regulates thermotolerance via activation of LlEIN3 and LlHSFA2, along with an antagonistic interaction with LlSPT. [ABSTRACT FROM AUTHOR]

Turfgrass seeds are often sold as mixtures of several species to increase the probability of positive responses toward abiotic and biotic stresses, a response to drought being one of these. Several species of turfgrass are already thought to be better suited for drought, such as hard fescue (Festuca brevipila Tracey) and tall fescue [Schedonorus arundinaceus (Schreb.) Dumort]. However, little is known about the benefit of these species in mixtures with drought‐intolerant and/or drought‐avoiding species during drought. Understanding species mixture composition during establishment, before and after drought stress periods, could help develop more resilient mixtures for this stress condition. We compared monocultures and mixtures of hard fescue, Kentucky bluegrass (Poa pratensis L.), and perennial ryegrass (Lolium perenne L.) during sequential short drought and recovery periods in controlled conditions. We observed that the composition of most mixtures remained similar during drought and recovery periods; however, perennial ryegrass was often less prevalent after drought stress. We found that hard fescue monocultures had better green leaf coverage than Kentucky bluegrass and perennial ryegrass during drought stress. However, the presence of hard fescue in mixtures was not an indicator of greater drought tolerance, and variable fluorescence to maximal fluorescence data indicated that hard fescue was just as physiologically stressed as perennial ryegrass and Kentucky bluegrass during the drought periods. These results indicate that while hard fescue seems visually drought tolerant, it is still physiologically stressed and improved drought tolerance could be achieved through focusing on physiological indicators of stress in this species rather than visual indicators. [ABSTRACT FROM AUTHOR]

The health monitoring of planted forests is essential for the planning, management and management of these areas, which are fundamental for the economy and ecosystem services. In this sense, this review explicitly focuses on studies related to the monitoring of commercial forests threatened by biotic and abiotic stress factors. Our objective was to examine studies related to the remotely piloted aircraft (RPAS) remote sensing data, methods and technologies used, as well as discuss scientific and technical advances that could further increase the potential of RPAS for forestry in the future. A systematic bibliometric review of articles published between 2015 and 2023 was carried out. In total, 29 scientific articles were obtained, where the results revealed the preference for multispectral sensors for monitoring biotic and abiotic stress. RPAS, with the integration of passive and active sensors, and associated artificial intelligence technologies, are excellent options for the development of monitoring the health of planted forests, as they allow the rapid and accurate acquisition of information, as well as the ability to predict potential changes. Finally, monitoring crop health and vigor through RPAS has proven to be effective and robust, as evidenced by the authors in their research. [ABSTRACT FROM AUTHOR]

Background: The lignification of branches can promote the accumulation of nutrients, increase plant survival and resistance to biotic and abiotic stresses. As an important carbon source for plants, glucose is also the carbon skeleton for lignin synthesis. Grapevine is a perennial cash crop, and highly lignified branches are essential to ensure the growth of the grapevine plant and the development of the fruit. Methods: Here, 'Red Globe' grape (Vitis vinifera L.) plantlets were selected as the material and cultured with different concentrations of glucose: 0 g/L, 20 g/L, 40 g/L and 60 g/L glucose (G0, G20, G40 and G60). Among them, G0 group as control. Lignin, anthocyanins and glucose contents, plant height and microstructure were measured at each glucose concentration after 40-, 50-, and 60-day treatments. Transcriptome and metabolome were used to analyze the difference in genes and metabolites after 50 days of growth. Results: After 50 days of cultivation, the lignin content in G40 group was the highest. And the xylem cells number also increased. To further, transcriptome and metabolome have identified a total of 3638 differentially expressed genes (DEGs) (including 245 TFs) and 510 differently accumulated metabolites (DAMs) in three comparison groups. In-depth joint analysis revealed that phenylpropanoid biosynthesis pathway significantly respond to exogenous glucose, and 37 DEGs were identified. Therefore, the phenylpropane biosynthesis pathway may be the key to exogenous glucose to increase lignin levels in grapes, with differential expression of genes being a top priority. These findings provide a new perspective for understanding the relationship between glucose and lignin in grape. [ABSTRACT FROM AUTHOR]