Stress Tolerance In Crops Research Articles

Enhancing Drought Tolerance in Lettuce: The Efficacy of the Seaweed-Derived Biostimulant Cytolan® Stress Applied at Different Growth Stages

Water stress is one of the foremost global abiotic stressors limiting agricultural productivity. Biostimulants and bioactive compounds are emerging as promising tools to enhance crop stress tolerance. This study investigates the effects of Cytolan® Stress, a novel seaweed-derived biostimulant, on the water stress tolerance of lettuce plants. Three application strategies were evaluated: priming, where the biostimulant is applied before the onset of stress to prepare the plants for adverse conditions; buffering, involving application at the onset of stress to mitigate its immediate effects; and detoxifying, where the biostimulant is applied after stress to aid in plant recovery. Biomass, stress-related parameters, antioxidant activity, osmoprotectant levels, and photosynthesis-related metrics were analyzed to elucidate its potential mechanisms of action. The results demonstrated that Cytolan® Stress in priming and buffering applications significantly improved water stress tolerance, reducing biomass loss from 45% to only 25%. Moreover, the detoxifying treatment was the most effective, as plants showed biomass values similar to those of the control plants. The biostimulant reduced oxidative stress indicators while enhancing antioxidant defenses, including ascorbate (AsA)-glutathione (GSH) cycle, antioxidant compounds, and enzyme activities. In addition, Cytolan® Stress preserved photosynthesis performance under water stress conditions. These findings highlight the potential of Cytolan® Stress to mitigate drought stress effects in lettuce, offering broader implications for crop tolerance and resilience under water-limited conditions. Further studies are recommended to explore its efficacy across different crops and stress scenarios.

Partial root‐zone drying irrigation enhances synthesis of glutathione in barley roots to improve low temperature tolerance

SUMMARYPartial root‐zone drying irrigation (PRD) has been widely employed to regulate crop root development and responses to environmental fluctuations. However, its role in reprogramming rhizospheric microorganisms and inducing plant stress tolerance remains largely unexplored. This study aimed to investigate the effects of PRD on the response of barley (Hordeum vulgare) plants to low temperatures under various irrigation regimes. Under low temperature, barley plants subjected to PRD exhibited a significantly enhanced net photosynthetic rate, stomatal conductance, and maximum quantum efficiency of photosystem II compared to fully irrigated plants. Additionally, these plants showed a reduction in relative conductance. These results suggest that PRD could be a viable strategy for enhancing crop stress tolerance through irrigation management. Metabolomic analysis revealed that PRD influenced the accumulation of glutathione and 9‐octadecenamide in roots under low temperature, which was corroborated by transcriptome profiling data. Furthermore, the study highlighted the close association between this regulatory process and rhizosphere core microorganisms, such as Sphingobium and Mortierella, enriched in barley roots under PRD. This study revealed the mechanism underlying plant stress tolerance induction by PRD and the roles of rhizosphere microorganisms in this process. Also, the current study suggests that PRD is a promising strategy for enhancing crop stress tolerance through effective irrigation management.

Emerging strategies to improve heat stress tolerance in crops

Abstract The heat stress (HS) response in plants involves complex processes at the molecular, cellular, and whole-organism levels. Sensitivity to HS differs based on the species and developmental stage of the plant, making it challenging to define HS and its impacts. Efforts to enhance HS tolerance by traditional breeding are constrained by limited genetic resources, but understanding the mechanisms that regulate HS responses can enable efforts to improve heat tolerance by precision breeding and gene editing. Here, we review recent research on the effects of HS on major cereal crops at different developmental stages and identify key genes potentially involved in the HS response, offering insight for precision molecular breeding. Additionally, we discuss the use of favorable natural variants and gene editing to improve crop tolerance to HS, emphasizing the value of alleles involved in thermomemory, combined stress tolerance, and the stress response–growth balance. This review aims to summarize recent advancements in understanding HS responses in crops, highlighting potential avenues for generating heat-tolerant crops.

Plant secondary metabolites against biotic stresses for sustainable crop protection.

Sustainable agriculture practices are indispensable for achieving a hunger-free world, especially as the global population continues to expand. Biotic stresses, such as pathogens, insects, and pests, severely threaten global food security and crop productivity. Traditional chemical pesticides, while effective, can lead to environmental degradation and increase pest resistance over time. Plant-derived natural products such as secondary metabolites like alkaloids, terpenoids, phenolics, and phytoalexins offer promising alternatives due to their ability to enhance plant immunity and inhibit pest activity. Recent advances in molecular biology and biotechnology have improved our understanding of how these natural compounds function at the cellular level, activating specific plant defense through complex biochemical pathways regulated by various transcription factors (TFs) such as MYB, WRKY, bHLH, bZIP, NAC, and AP2/ERF. Advancements in multi-omics approaches, including genomics, transcriptomics, proteomics, and metabolomics, have significantly improved the understanding of the regulatory networks that govern PSM synthesis. These integrative approaches have led to the discovery of novel insights into plant responses to biotic stresses, identifying key regulatory genes and pathways involved in plant defense. Advanced technologies like CRISPR/Cas9-mediated gene editing allow precise manipulation of PSM pathways, further enhancing plant resistance. Understanding the complex interaction between PSMs, TFs, and biotic stress responses not only advances plant biology but also provides feasible strategies for developing crops with improved resistance to pests and diseases, contributing to sustainable agriculture and food security. This review emphasizes the crucial role of PSMs, their biosynthetic pathways, the regulatory influence of TFs, and their potential applications in enhancing plant defense and sustainability. It also highlights the astounding potential of multi-omics approaches to discover gene functions and the metabolic engineering of genes associated with secondary metabolite biosynthesis. Taken together, this review provides new insights into research opportunities for enhancing biotic stress tolerance in crops through utilizing plant secondary metabolites.

The comprehensive regulatory network in seed oil biosynthesis.

Plant oils play a crucial role in human nutrition, industrial applications and biofuel production. While the enzymes involved in fatty acid (FA) biosynthesis are well-studied, the regulatory networks governing these processes remain largely unexplored. This review explores the intricate regulatory networks modulating seed oil biosynthesis, focusing on key pathways and factors. Seed oil content is determined by the efficiency of de novo FA synthesis as well as influenced by sugar transport, lipid metabolism, FA synthesis inhibitors and fine-tuning mechanisms. At the center of this regulatory network is WRINKLED1 (WRI1), which plays a conserved role in promoting seed oil content across various plant species. WRI1 interacts with multiple proteins, and its expression level is regulated by upstream regulators, including members of the LAFL network. Beyond the LAFL network, we also discuss a potential nuclear factor-Y (NF-Y) regulatory network in soybean with an emphasis on NF-YA and NF-YB and their associated proteins. This NF-Y network represents a promising avenue for future efforts aimed at enhancing oil accumulation and improving stress tolerance in soybean. Additionally, the application of omics-based approaches is of great significance. Advances in omics technologies have greatly facilitated the identification of gene resources, opening new opportunities for genetic improvement. Importantly, several transcription factors involved in oil biosynthesis also participate in stress responses, highlighting a potential link between the two processes. This comprehensive review elucidates the complex mechanisms underlying the regulation of oil biosynthesis, offering insights into potential biotechnological strategies for improving oil production and stress tolerance in oil crops.

Physio-biochemical and molecular mechanisms of low nitrogen stress tolerance in peanut (Arachis hypogaea L.).

Nitrogen (N) is a major plant nutrient and its deficiency can arrest plant growth. However, how low-N stress impair plant growth and its related tolerance mechanisms in peanut seedlings has not yet been explored. To counteract this issue, a hydroponic study was conducted to explore low N stress (0.1mM NO3-) and normal (5.0mMNO3-) effects on the morpho-physiological and molecular attributes of peanut seedlings. Low-N stress significantly decreased peanut plant height, leaf surface area, total root length, and primary root length after 10days of treatment. Meanwhile, glutamate dehydrogenase, glutamine oxoglutarate aminotransferase activities, chlorophyll, and soluble protein contents were substantially decreased. Impairment in these parameters further suppressed photochemical efficiency (Fv/Fm), and chlorophyll fluorescence parameters (PIABS), under low-N stress. Transcriptome sequencing analysis showed a total of 2139 DEGs were identified between the two treatments. KEGG enrichment annotation analysis of DEGs revealed that 119 DEGs related to 10 pathways, including N assimilation, photosynthesis, starch, and sucrose degradation, which may respondto low-N stress in peanuts. Combined with transcriptome, small RNA, and degradome sequencing, we found that PC-3p-142756_56/A.T13EMM (CML3) and PC-5p-43940_274/A.81NSYN (YTH3) are the main modules contributing to low N stress tolerance in peanut crops. Peanut seedlings exposed to N starvation exhibited suppressed gene expression related to nitrate transport and assimilation, chlorophyll synthesis, and carbon assimilation, while also showing improved gene expression in N compensation/energy supply and carbohydrate consumption. Additionally, low N stress tolerance was strongly associated with the miRNA.

SAL1 gene: a promising target for improving abiotic stress tolerance in plants a mini review.

Global climate change poses a significant risk to agricultural productivity due to its diverse impacts on agricultural ecosystems, such as increased temperatures and altered precipitation patterns, all of which can adversely affect crop productivity. To overcome these challenges, plants have evolved intricate mechanisms to regulate stress responses and enhance stress tolerance. The SAL1 gene, which encodes a phosphatase enzyme, has emerged as a key player in plant stress responses. In this review, we provide an overview of the SAL1 gene, its functional significance, and its potential applications for improving stress tolerance in crops. To address the escalating global food demand amidst climate change challenges, it is imperative to pursue innovative strategies aimed at enhancing crop tolerance against abiotic stress.

Atp24δ8, a p24 family member, regulates the unfolded protein response and ER stress tolerance in Arabidopsis.

ER stress activates the unfolded protein response (UPR), a critical mechanism for maintaining cellular homeostasis in plants. The p24 protein family is known to be involved in protein trafficking between the endoplasmic reticulum (ER) and the Golgi apparatus, but its role in ER stress remains unclear in plants. In this study, we found that Atp24δ8(delta8), a member of the δ-2 subclass of the p24 family, is significantly upregulated in response to tunicamycin-induced ER stress. Subcellular localization confirmed that Atp24δ8 resides in the ER, and CRISPR-Cas9 loss-of-function mutants displayed increased sensitivity to ER stress. Further analysis showed that Atp24δ8 regulates key UPR genes, highlighting its role in promoting ER stress tolerance. These findings provide new insights into the molecular mechanisms that plants use to cope with ER stress, potentially contributing to the development of stress-tolerant crops.

Knockdown of OsPHP1 Leads to Improved Yield Under Salinity and Drought in Rice via Regulating the Complex Set of TCS Members and Cytokinin Signalling.

Plant two-component system (TCS) is crucial for phytohormone signalling, stress response, and circadian rhythms, yet the precise role of most of the family members in rice remain poorly understood. In this study, we investigated the function of OsPHP1, a pseudo-histidine phosphotransfer protein in rice, using a functional genomics approach. OsPHP1 is localised in the nucleus and cytosol, and it exhibits strong interactions with all sensory histidine kinase proteins (OsHK1-6) and cytokinin catabolism genes. Our results demonstrate that OsPHP1 functions as a negative regulator of cytokinin signalling. Knockdown of OsPHP1 enhanced the expression of positive cytokinin signalling regulators, such as OsHKs and OsAHPs (authentic phosphotransfer proteins), while downregulating negative regulators, such as type-A response regulators (OsRRs) and cytokinin catabolism genes (CKXs). Furthermore, OsPHP1 negatively influences abiotic stress tolerance, as evidenced by the increased sensitivity of OsPHP1-OE (overexpression) lines to salinity and drought. In contrast, OsPHP1-KD (knockdown) lines showed enhanced stress resilience, with better photosynthesis, increased tiller and panicle production, higher spikelet fertility, and grain filling. The study demonstrates that OsPHP1 suppresses antioxidant and stress-responsive genes, exacerbating ion toxicity and reducing osmolyte accumulation, thereby impairing plant growth and yield under stress conditions. These findings highlight OsPHP1 as a critical modulator of plant responses to abiotic stress and suggest potential genetic targets for enhancing crop stress tolerance.

Overexpression of rice High-affinity Potassium Transporter gene OsHKT1;5 improves salinity and drought tolerance in Arabidopsis.

Rice is subjected to various environmental stresses, resulting in significant production losses. Abiotic stresses, particularly drought and salinity, are the leading causes of plant damage worldwide. The High-affinity Potassium Transporter (HKT) gene family plays an important role in enhancing crop stress tolerance by regulating physiological and enzymatic functions. This study investigates the effect of overexpressing the rice HKT1;5 gene in Arabidopsis thaliana on its tolerance to salinity and drought. The OsHKT1;5 gene was introduced into Arabidopsis under the control of 35S promoter of CaMV via floral dip transformation method. PCR confirmed the integration of the transgene into the Arabidopsis genome, while qPCR analysis showed its expression. Three transgenic lines of OsHKT1;5 were used for stress treatment and phenotypic studies. The overexpressed lines showed considerably higher germination rates, increased leaf counts, greater fresh and dry weights of the roots and shoots, higher chlorophyll contents, longer root lengths, and reduced Na+ levels together with increased K+ ions levels after salt and drought treatments, in comparison to wild-type plants. Furthermore, overexpressed lines exhibited higher antioxidant levels than wild-type plants under salinity and drought conditions. In addition, transgenic lines showed higher expression levels of the OsHKT1;5 gene in both roots and shoots compared to wild-type plants. In conclusion, this study revealed OsHKT1;5 as a promising candidate for enhancing tolerance to salinity and drought stresses in rice, marking a significant step toward developing a new rice variety with improved abiotic stress tolerance.

Adapting crops for climate change: regaining lost abiotic stress tolerance in crops

Adapting crops for climate change: regaining lost abiotic stress tolerance in crops

Physiological and Transcriptomic Dynamics in Mulberry: Insights into Species-Specific Responses to Midday Depression.

Background/Objective: The midday depression of photosynthesis, a physiological phenomenon driven by environmental stress, impacts plant productivity. This study aims to elucidate the molecular and physiological responses underlying midday depression in two mulberry species, Ewu No. 1 (Ew1) and Husan No. 32 (H32), to better understand their species-specific stress adaptation mechanisms. Methods: RNA-seq analysis was conducted on leaf samples collected at three time points (10:00 a.m., 12:00 p.m., and 4:00 p.m.), identifying 22,630 differentially expressed genes (DEGs). A comparative Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed to reveal the involvement of key metabolic and signaling pathways in stress responses. Results: Ew1 displayed enhanced stress tolerance by upregulating genes involved in energy management, water conservation, and photosynthetic processes, maintaining higher photosynthetic rates under midday stress. In contrast, H32 adopted a more conservative response, downregulating genes related to photosynthesis and metabolism, favoring survival at the expense of productivity. The KEGG analysis highlighted starch and sucrose metabolism and plant hormone signaling as critical pathways contributing to these species-specific responses. Conclusions: Ew1's adaptive molecular strategies make it more suitable for environments with variable light and temperature conditions, while H32's conservative approach may limit its productivity. These findings provide valuable insights for breeding programs aimed at improving stress tolerance and photosynthetic efficiency in mulberry and other crops, particularly under fluctuating environmental conditions.

Glucosinolates Mediated Regulation of Enzymatic Activity in Response to Oxidative Stress in Brassica spp.

Brassica crops are vital as they supply essential minerals, antioxidants, and bioactive substances like anthocyanins, glucosinolates, and carotenoids. However, biotic and abiotic elements that cause oxidative stress through heavy metals and other eco-toxicants pose a risk to Brassica plants. Increased generation of Reactive Oxygen Species (ROS) causes oxidative stress, which damages biomolecules and interferes with plant growth, productivity, and cellular equilibrium. Plants producing Brassica need an intricate enzyme defence mechanism to fend off oxidative stress. All the enzymes that have been addressed are found in mitochondria, peroxisomes, chloroplasts, and other cell components. They are in charge of removing ROS and preserving the cell's redox balance. Additionally, Brassica plants use secondary metabolites called Glucosinolates (GLs), which have the capacity to regulate enzymatic activity and act as antioxidants. By breaking down compounds like sulforaphane, GLs boost antioxidant enzymes and provide protection against oxidative stress. To develop methods for improving agricultural crop stress tolerance and productivity in Brassica, it is necessary to comprehend the dynamic interaction between GL metabolism and enzymatic antioxidant systems. This highlights the possibility of maximizing antioxidant defences and raising the nutritional and commercial value of Brassica across the globe by utilizing genetic diversity and environmental interactions.

Hydrogen Sulphide: A Key Player in Plant Development and Stress Resilience.

Based on the research conducted so far, hydrogen sulphide (H2S) plays a crucial role in the development and stress resilience of plants. H2S, which acts as a signalling molecule, responds to different stresses such as heavy metals, drought, and salinity, and it regulates various aspects of plant growth and development including seed germination, root development, stomatal movement, flowering, and fruit ripening. Additionally, H2S is involved in mediating legume-Rhizobium symbiosis signalling. It modulates plant responses to external environmental stimuli by interacting with other signalling molecules like phytohormones, nitric oxide, and reactive oxygen species. Furthermore, H2S exerts these regulations since it can modify protein functions through a reversible thiol-based oxidative posttranslational modification called persulfidation, particularly in stress response and developmental processes. As a result, H2S is recognised as an important emerging signalling molecule with multiple roles in plants. Research in this field holds promise for engineering stress tolerance in crops and may lead to potential biotechnological applications in agriculture and environmental management.

Strigolactone as a potential target for improving abiotic stress tolerance in horticultural crops

Strigolactone as a potential target for improving abiotic stress tolerance in horticultural crops

Impact of homologous overexpression of PR10a gene on improving salt stress tolerance in transgenic Solanum tuberosum

Abiotic stresses severely affected crop productivity and considered to be a major yield limiting factor for crop plant. The tolerance to these stresses is a very complex phenomenon involving a wide array of molecular, biochemical and physiological changes in plant cells. Therefore, it is challenging to understand the molecular basis of abiotic stress tolerance to manipulate it for improving abiotic stress tolerance of major crops. Biotechnological approaches and genetic engineering including homologous gene overexpression can be implemented to understand gene functions under well-defined conditions. The Pathogenesis-related proteins (PR10) such as PR10a play multiple roles in biotic and abiotic stress tolerance and, hence, plant development. A PR10a gene from potato cv. Deseree was introduced into three cultivars of potato (Solanum tuberosum L.) by Agrobacterium tumefaciens-mediated genetic transformation. Transgenic plants were selected on a medium containing 1.0 mg/l phosphinothricin (PPT) and confirmed by polymerase chain reaction (PCR), herbicide (BASTA®) leaf paint assay, and Real-Time- quantitative PCR analyses (qPCR). All of the selected transformants showed completely tolerance to the application of PPT application. Experiments designed for testing salt tolerance revealed that there was enhanced salt tolerance of the transgenic lines in vitro in terms of morphological (plant FW, plant DW and plant height) and antioxidant activates as compared to the non-transgenic control plants. qRT-PCR showed that the expression of PR10a gene in the transgenic potato is higher than that in non-transgenic control under salt stress. The relative PR10a gene-expression patterns in the transgenic plants shed lights into the molecular response of homologues overexpressed PR10a potato to salt-stress conditions. The obtained results provide insights on the fact that PR10a plays a major role regarding salt stress tolerance in potato plants.

RNA modifications in plant adaptation to abiotic stresses.

Epitranscriptomic chemical modifications of RNAs have emerged as potent regulatory mechanisms in the plant stress adaptation process. Currently, over 170 distinct chemical modifications have been identified in mRNAs, tRNAs, rRNAs, microRNAs (miRNAs), and long-noncoding RNAs (lncRNAs). The genetic and molecular studies have identified the genes responsible for adding and removing chemical modifications on RNA molecules, known as "writers" and "erasers," respectively. Among the identified chemical modifications in mRNAs, N6-methyladenosine (m6A) is the most prevalent modification in eukaryotic mRNAs. Recent studies have identified m6A writers and erasers across different plant species, including Arabidopsis (Arabidopsis thaliana), rice (Oryza sativa), cotton (Gossypium hirsutum), and tomato (Solanum lycopersicum). Accumulating discoveries have improved our understanding of the functions of RNA modifications in plant stress responses. This review highlights the latest developments in RNA modification research, emphasizing the biological and cellular roles of diverse chemical modifications in mRNAs, tRNAs, rRNAs, miRNAs, and lncRNAs in the plant response to environmental and hormonal signals. Moreover, we propose and discuss the critical questions and future challenges in enhancing our understanding of the cellular and mechanistic roles of RNA modifications in plant stress responses. Integrating molecular insights regarding the regulatory roles of RNA modifications in stress responses with novel genome- and RNA-editing technologies will facilitate the breeding of stress-tolerant crops via precise engineering of RNA modifications.

Comparative analysis of amino acid sequence level in plant GATA transcription factors

Transcription factors (TFs) are essential regulators of gene expression, influencing numerous biological processes such as development, growth, and cellular responses in plants. Among these, GATA TFs are distinguished by their highly conserved DNA-binding domain, characterized by a class IV zinc finger motif (CX2CX18-20CX2C). This study investigates the amino acid sequence patterns of 5,335 GATA TFs across 165 plant species sourced from the PlantTFDB database (http://planttfdb.gao-lab.org/), encompassing diverse taxonomic groups. Through comparative sequence analysis, I identify conserved domains and structural features that enhance the understanding functional roles, evolutionary conservation, and lineage-specific adaptations of GATA TFs. These findings provide valuable insights into the diversification and functional specialization of GATA TFs, with implications for improving stress tolerance and adaptability in crops. This study contributes to the broader knowledge of transcriptional regulation in plant biology.

Enhanced salt stress tolerance in plants without growth penalty through increased photosynthesis activity by plastocyanin from Antarctic moss.

Salinity poses a significant challenge to plant growth and crop productivity by adversely affecting crucial processes, including photosynthesis. Efforts to enhance abiotic stress tolerance in crops have been hindered by the trade-off effect, where increased stress resistance is accompanied by growth reduction. In this study, we identified and characterized a plastocyanin gene (PaPC) from the Antarctic moss Polytrichastrum alpinum, which enhanced photosynthesis and salt stress tolerance in Arabidopsis thaliana without compromising growth. While there were no differences in growth and salt tolerance between the wild type and Arabidopsis plastocyanin genes (AtPC1 and AtPC2)-overexpressing plants, PaPC-overexpressing plants demonstrated superior photosynthetic efficiency, increased biomass, and enhanced salt tolerance. Similarly, PaPC-overexpressing rice plants exhibited improved yield potential and photosynthetic efficiency under both normal and salt stress conditions. Key amino acid residues in PaPC responsible for this enhanced functionality were identified, and their substitution into AtPC2 conferred improved photosynthetic performance and stress tolerance in Arabidopsis, tobacco, and tomato. These findings not only highlight the potential of extremophiles as valuable genetic resources but also suggest a photosynthesis-based strategy for developing stress-resilient crops without a growth penalty.

Microcontroller-based water control system for evaluating crop water use characteristics

BackgroundClimate change and the growing demand for agricultural water threaten global food security. Understanding water use characteristics of major crops from leaf to field scale is critical, particularly for identifying crop varieties with enhanced water-use efficiency (WUE) and stress tolerance. Traditional methods to assess WUE are either by gas exchange measurements at the leaf level or labor-intensive manual pot weighing at the whole-plant level, both of which have limited throughput.ResultsHere, we developed a microcontroller-based low-cost system that integrates pot weighing, automated water supply, and real-time monitoring of plant water consumption via Wi-Fi. We validated the system using major crops (rice soybean, maize) under diverse stress conditions (salt, waterlogging, drought). Salt-tolerant rice maintained higher water consumption and growth under salinity than salt-sensitive rice. Waterlogged soybean exhibited reduced water use and growth. Long-term experiments revealed significant WUE differences between rice varieties and morphological adaptations represented by altered shoot-to-root ratios under constant drought conditions in maize.ConclusionsWe demonstrate that the system can be used for varietal differences between major crops in their response to drought, waterlogging, and salinity stress. This system enables high-throughput, long-term evaluation of water use characteristics, facilitating the selection and development of water-saving and stress-tolerant crop varieties.