Climate change regulated abiotic stress mechanisms in plants: a comprehensive review

The teamwork of melatonin, ethylene and H2S in abiotic stress adaptation in plants

Abiotic stresses significantly reduce plant growth and productivity, challenging agricultural sustainability. Plants have evolved adaptive mechanisms to counter these stresses, including antioxidant defences, biochemical changes, and hormonal signaling. Among these, the hormone melatonin (MT) and signaling molecules, ethylene (ET) and hydrogen sulfide (H2S), play pivotal roles, interacting in complex ways that modulate stress responses. Melatonin, known for its antioxidant properties, interacts with ET pathways to regulate its production. While ET is essential for stress signaling, its overproduction can exacerbate oxidative damage, and MT helps modulate ET levels to prevent such detrimental effects. Moreover, MT regulates H2S synthesis by activating L-cysteine desulfhydrase (LCD) and D-cysteine desulfhydrase (DCD), enhancing its protective effects under stress. Hydrogen sulfide supports MT synthesis, indicating a bidirectional relationship. Evidence suggests that H2S plays a role in fine-tuning ET levels under stress conditions, supporting optimal signaling for resilience. This review explores the intricate interactions among MT, ET, and H2S, shedding light on potential crosstalk mechanisms that strengthen plant stress tolerance, aiming to enhance crop resilience through targeted manipulation of these pathways.

Transcriptomic and Metabolomic Profiling Reveal the Close Implication of Alkaloid Biosynthesis and Ureide Metabolism to Drought Stress Tolerance in Maize

Addressing sustainable agriculture production and food security requires a thorough understanding of the crop drought response. Although the importance of secondary metabolites in mediating drought tolerance (DT) has been extensively reported, the implication of alkaloids and urea in maize DT remains elusive. Here, through evaluating the physiological, transcriptome, and metabolome responses of two maize varieties, CIMMYT PAK (C, drought tolerant) and Haq Nawaz (H, drought sensitive), we found that alkaloid biosynthesis and ureide metabolism were particularly significantly induced under DS (drought stress) in C. Notably, lupanine and (S)-ureidoglycolate were 20.87-fold and over 37-fold up-regulated under DS in C. Five key candidate genes, including ZmAPY3, were uncovered. In addition, other critical pathways and genes in response to DS were revealed, highlighting key drought-responsive mechanisms in maize. Our results provide new insights into the DT mechanisms of maize. The molecular contribution of alkaloid and ureide metabolism to maize DT deserves further in-depth investigations.

Transcriptomic and Metabolomic Evidence Reveal the Vital Role of Lactose in the Acquisition of Rapid Desiccation Tolerance in Boea hygrometrica

Prior exposure of plants to a triggering factor can enhance their tolerance to more severe stressful events. Transcriptome reprogramming of metabolism and hormonal modulation processes in the resurrection plant Boea hygrometrica was observed during drought acclimation. However, the metabolic dynamics and underlying regulatory networks that modulate drought acclimation-induced rapid desiccation tolerance (RDT) remain unexplored. Here, we performed an integrated transcriptome and metabolome analysis to investigate the phytohormone profiles and metabolic landscapes of B. hygrometrica during drought acclimation and dehydration stress. We identified a set of RDT acquisition-associated biomarkers, including trans-zeatin and some disaccharides (lactose, trehalose, sucrose, and isomaltulose). Exogenous application of lactose effectively enhanced the RDT of B. hygrometrica seedlings and improved drought tolerance in Arabidopsis, tobacco, maize, and wheat. In addition, transient overexpression of lactose-associated transcription factors MYB330 and APETALA2 in B. hygrometrica can promote the RDT and transcription of drought acclimation-inducible genes involved in calcium and ABA signalling and autophagy. In summary, our findings demonstrate that drought acclimation-induced lactose accumulation facilitates the establishment of an "acclimated state", leading to transcriptome reprogramming in response to rapid desiccation. These results will also pave the way for using RDT biomarkers to improve crop drought tolerance in an environmentally sustainable manner.

Phenolic compounds, antioxidant enzymes, and oxidative stress in barley (Hordeum vulgare L.) genotypes under field drought-stress conditions

Climate change has exacerbated drought, making water scarcity a significant constraint on crop production. This study aimed to evaluate drought stress responses of 21 barley cultivars and breeding lines, using various traits of leaf oxidative stress [DPPH radical scavenging, malondialdehyde (MDA), and hydrogen peroxide (H2O2)], antioxidants (enzymes and polyphenols), photosynthetic pigments and chlorophyll fluorescence (F) [carotenoid (Car), chlorophyll (Chl), Fm, F0, and Fv/Fm], relative water content (RWC), electrolyte leakage (EL), proline (Pro), protein content (PC), and grain yield. Field experiments were conducted under both normal and drought stress conditions. Significant effects of moisture conditions were observed for most of the traits, except for Chla/b, carotenoids, and EL. Syringic acid, gallic acid, chlorogenic acid, ferulic acid, ellagic acid, caffeic acid, vanillic acid, and p-coumaric acid were the prominent phenolic acids in barley genotypes. The predominant leaf flavonoids were luteolin, apigenin, and rutin. There was significant genetic variation among genotypes for all traits except Chla/b. Drought stress caused significant increases in DPPH, MDA, H2O2, total phenolic content, total flavonoid content, peroxidase, and Pro. While catalase, ascorbate peroxidase, Chla, Chlb, Tchl, Fv/Fm, F0, Fm, RWC, PC, and grain yield were significantly decreased due to water stress. These findings offer key insights into barley genotypes' drought stress response, aiding breeders in identifying key physiological and biochemical traits as markers for developing drought-tolerant cultivars.

Exploration of the Plant World: Application and Innovation of Plant-Wearable Sensors for Real-Time Detection

Plants play a crucial role in improving the environment by regulating the temperature, preventing soil erosion, and reducing wind speed. By yielding edible resources such as food crops, vegetables, and fruits, plants also provide essential nutrients for human beings. Consequently, the real-time monitoring of plant growth and surrounding environment has been the primary focus of researchers. Traditional plant monitoring relies on manual inspection, which is both subjective and discontinuous. In recent years, ongoing advancements in wearable sensors have enabled their application in various areas of plant monitoring such as plant growth assessment, environmental monitoring, nutritional detection, water management, and pest warning. These wearable sensors can be directly fixed to plant organs to deliver real-time data on plant growth and environmental conditions via wireless connections with smart devices. This facilitates user management and monitoring, which can contribute to the development of intelligent agriculture with high planting efficiency and sustainability. This review summarizes the design principles, manufacturing methods, characteristics, and feasibility of plant-wearable sensors based on their functions, including plant-phenotype sensors (e.g., hormones and nutrients), plant-growth-environment sensors (e.g., surrounding humidity), and plant stress sensors (e.g., pesticides, volatile organic compounds, and environmental stress). It also explores the challenges and development prospects in this field, providing valuable insights into the future application of wearable sensors to effectively optimize the plant growth status for crop yield and quality.

Predicting the spread of invasive Imperata cylindrica under climate change: A global risk assessment and future distribution scenarios

Invasive plant species, such as Imperata cylindrica (cogongrass), threaten native ecosystems, natural resources, and lands worldwide. With climate change, the risk of invasions may increase as more favorable conditions enable non-native species to spread into new areas. This study employs the CLIMEX model to predict the potential distribution of I. cylindrica under current and future climate scenarios, under the SRES A2 scenario. A comprehensive dataset comprising 6,414 occurrence records was used to simulate the species' ecological niche based on key climatic parameters, including temperature and soil moisture. Our results indicate that more than 16% of the global land surface is currently highly suitable for I. cylindrica (Ecoclimatic Index ≥ 30), with significant risk areas identified in Central America, Africa, and Australia. Future projections under the A2 scenario suggest an expansion of suitable habitats by 2050, 2080, and 2100, particularly in regions such as southern Argentina and parts of North America, while areas in Africa may experience a decrease in suitability due to rising temperatures. Sensitivity analysis revealed that temperature-related parameters (DV0, DV1, DV2, and DV3) are the most influential in determining the species' distribution, highlighting the critical role of climate in driving the invasive potential of I. cylindrica. These findings provide valuable insights into the future risks associated with I. cylindrica invasions.

Ozone risk assessment of common cypress (Cupressus sempervirens L.) clones and effects of Seiridium cardinale infection

Cupressus sempervirens is a relevant species in the Mediterranean for its cultural, economic and landscape value. This species is threatened by Seiridium cardinale, the causal agent of the cypress canker disease (CCD). The effects of biotic stressors on O3 risk assessment are unknown and a comprehensive O3 risk assessment in C. sempervirens is missing. To fill these gaps, two clones of C. sempervirens, one resistant (Clone R) and one susceptible to CCD (Clone S), were subjected to three levels of O3 (Ambient Air - AA; 1.5 × AA; 2.0 × AA) for two consecutive years in an O3-free-air controlled exposure facility and artificially inoculated with S. cardinale. Both the exposure- (AOT40) and flux-based (PODy) indices were tested. We found that PODy performed better than AOT40 to assess O3 effects on biomass and the critical level for a 4% biomass loss was 2.51 mmol/m2 POD2. However, significant O3 dose-response relationships were not found for the inoculated cypresses because the combination of middle level O3 (1.5 × AA) and inoculation stimulated a biomass growth in Clone S as hormetic response. Moreover, we found a different inter-clonal response to both stressors with a statistically significant reduction of total and belowground biomass following O3, and lower root biomass in Clone S than in Clone R following pathogen infection. In summary, Clone R was more resistant to O3, and inoculation altered O3 risk via an hormetic effect on biomass. These results warrant further studies on how biotic stressors affect O3 responses and risk assessment.

Cytokinin-based bioregulators improved heat stress tolerance by violaxanthin cycle activation and enhanced photoprotection in wheat (Triticum aestivum L.)

The study investigates the role of bioregulatory molecules in improving photoprotection and thermotolerance in wheat (Triticum aestivum L.) during terminal heat stress, a major threat to wheat production that drastically decreases yield and quality. The experiment was conducted on two genotypes, Chirya 3 (stay green) and HD 2329 (non stay green), grown under normal (11th November 2022) and late (4th January 2023) planting conditions to simulate heat stress. Foliar applications of bioregulatory compounds (BA, TDZ, GABA, BA + GABA, TDZ + GABA) and a water spray (control) were done at anthesis, with observations recorded at 7-day intervals, while carotenoid profiling and gene expression analyses were executed 14 days post-anthesis. Heat stress reduced total carotenoids while elevating non-photochemical quenching (NPQ), particularly in Chirya 3, signifying higher photoprotective energy dissipation. Bioregulatory treatments, including BA + GABA, reduced carotenoid degradation and improved NPQ, with TDZ exhibiting the highest NPQ in both cases. Carotenoid analysis indicated elevated zeaxanthin levels and reduced violaxanthin levels under stress, indicating the activation of the violaxanthin cycle. The expression of the TaVDE gene, essential for the violaxanthin cycle, enhanced during heat stress, with Chirya 3 demonstrating elevated expression levels. In particular, BA + GABA treatments enhanced TaVDE expression and photoprotective mechanisms. This work is the first investigation demonstrating that BA + GABA treatment can synergistically enhance wheat heat tolerance by modulating the violaxanthin cycle thus offering a promising strategy to mitigate the adverse effects of terminal heat stress.

Genome-Wide Identification and Characterization of Basic Pentacysteine Transcription Factors in Brassica napus

BARLEY B-RECOMBINANT/BASIC PENTACYSTEINE (BBR/BPC), a plant-specific transcription factor family, is a group of GAGA_motif binding factors controlling multiple developmental processes of growth and response to abiotic stresses. BPCs recruit histone remodeling factors for transcriptional repression of downstream targets. However, the information about BnaBPCs from Brassica napus remains unclear. Here, we identified 25 BnaBPC genes that were mainly localized in the nucleus, randomly localized on 16 chromosomes, and grouped into three subfamilies based on phylogenetic analysis. Twenty-five BnaBPC genes exhibit syntenic relationships with AtBPC genes, and the polypeptides encoded by BnaBPC genes within the same subfamily share similar conserved motifs and protein domains. The expansion of BnaBPC genes underwent whole-genome duplication events and purifying selection in genomes, and all the BnaBPC genes had the same conserved GAGA binding domains. Additionally, the promoter of each BnaBPC gene consisted of various cis-elements associated with stresses, phytohormones, and growth and development. Notably, the seed-specific regulatory element was found only in the BnaC04.BPC4 promoter. Further expression pattern analysis showed that BnaBPC members are widely expressed in stems, buds, developing seeds and siliques. These findings provide insights into BnaBPC genes and enrich our understanding of their functional characterization in B. napus.

Impacts of nitrogen fertilization and planting date on the physiology and yield of purple sweet potato at the extreme Northern edge of cultivation

Global warming causes plant stress and reduces crop productivity. Cultivation of the warmer region crop sweet potato (Ipomoea batatas (L.) Lam) in Northern regions can be an opportunity to benefit from climate warming, but there is little information of how growing season length interacts with agricultural practices such as nitrogen (N) fertilization. We studied the photosynthetic characteristics, biomass accumulation, carbon (C) and N contents of plant organs of the cultivar 'Purple Bud' in relation to the planting date (the 2nd of May, 10th of May, 20th of May, 30th of May and 10th of June) and N fertilization (kg ha-1; N0, N50, N100 and N150). Nitrogen content of leaves (NL) and tubers (NT) increased with N application dose and was moderately affected by planting time. Despite the fertilization-dependent increase of leaf N content, photosynthesis rate (A) was unaffected or somewhat reduced by N fertilization. This reflected reductions in stomatal conductance (gs) and ratio of intercellular CO2 to ambient CO2 (Ci/Ca), suggesting that enhanced N availability and concomitant increase in whole plant area resulted in reduced plant water availability. The highest values of leaf C/N ratio, tuber to root mass ratio and dry weight content of roots (DWR) were found in N0 plants and the ones planted on the 10th of May and 20th of May. Our results collectively demonstrate that the growth and productivity of sweet potato is strongly dependent on the length of the growing season, and can be further constrained by utilization efficiency of N. We conclude that future research should focus on optimum sweet potato cultivation technologies at Northern latitudes.

Genome-wide Identification, Characterization, and Expression Analysis of NHX Genes in Phaseolus vulgaris L. under Salt Stress: An In Silico Approach

BACKGROUND

Climate change is among the major triggering agents of abiotic stresses (e.g., saline stress), culminating in a vulnerability of common bean production systems. In recent decades, important research has identified and characterized genes that can mitigate the adverse effects caused by salt stress; among them, the Na+/H+ antiporters (NHXs) gene stands out. The NHX genes are widely distributed in all organisms and play significant roles in osmotic regulation in plants under salt stress conditions. Genome-wide identification of NHX genes has been performed in several plant species but not in Phaseolus vulgaris L.

METHODS

This study aimed to identify and characterize NHX genes in P. vulgaris L. using a genome-wide analysis approach conducted in silico. The common bean genome revealed nine putative PvNHX genes, and their subcellular localization, phylogenetic relationship, cis-regulatory elements, conserved motifs identification, chromosomal location, expression patterns, and interaction networks were analyzed.

RESULTS

Promoter analysis suggested that PvNHX genes shared hormone-related elements and were light-responsive and stress-responsive. Seven PvNHX genes were under the regulation of five microRNA (miRNA) families. RNA-seq analysis revealed that most PvNHX genes were expressed in response to salt stress. Currently, the most assertive strategy to confront these adversities is to use the information generated by sequencing plants to identify candidate genes that can be introgressed to improve programs in producing resilient cultures.

CONCLUSION

These results can provide valuable information for future studies on the functional mechanism of PvNHX genes in common beans in response to salt stress.

Current and future development of Acrocomia aculeata focused on biofuel potential and climate change challenges

The search for sustainable alternatives to petroleum has driven research on biofuels, with a focus on those derived from organic biomass. This study centres on macaúba (Acrocomia aculeata), a promising oilseed for biodiesel production. Advances in cultivation techniques and the mapping of climatically suitable areas are essential to consolidate the use of this species in the energy sector. This work aimed to utilise predictive modelling with the CLIMEX software to assess the current and future climatic suitability of macaúba in the context of climate change. Data on the global distribution of macaúba, growth and stress parameters, as well as climatic variables, were collected. The modelling was conducted based on the A2 SRES scenario for the present, 2050, 2080, and 2100, including the generation of the Weekly Growth Index. Results indicated high suitability in tropical regions, particularly in Brazil and Indonesia. However, future projections highlight significant challenges due to rising temperatures and reduced rainfall. The study provides a critical perspective to guide sustainable policies in the energy sector, underscoring the potential of macaúba as a viable biodiesel source while warning of the challenges posed by climate change.

Crop Wild Relatives (CWRs) in the United Arab Emirates: Resources for Climate Resilience and Their Potential Medicinal Applications

Global climate change threatens the production, growth, and sustainability of plants. Crop wild relatives (CWRs) offer a practical and sustainable solution to these climatic issues by boosting genetic diversity and crop resilience. Even though CWRs are wild relatives of domesticated plants, they are nevertheless mostly neglected. This review focuses on the possible application of CWRs, which are found in the United Arab Emirates (UAE) and are known for their abiotic stress tolerance and potential medicinal properties. In olden days, traditionally, CWRs has been used as medicine for various ailments as they are rich in phytochemical compounds. However, the medicinal potential of these wild plant species is decreasing at an alarming rate due to climate change stress factors. The medicinal potential of these native crop wild plant species must be investigated because they could be a useful asset in the healthcare sector. Research on pangenomics studies of certain CWRs is also highlighted in the review, which reveals genetic variability caused due to climate change stress factors and how these genetic variability changes affect the production of secondary metabolites that have potent medicinal value. This provides insights into developing personalized medicine, in which particular CWRs plant species can be chosen or modified to generate medicinal compounds. Despite their superior medicinal properties, many CWRs in the UAE are still not well understood. Finding the desired genes coding for the biosynthesis of specific phytochemicals or secondary metabolites may help us better understand how these substances are synthesized and how to increase their production for a range of treatments.

Genetic Variation of Growth Traits and Seed Production in a Patagonian Native Pasture in Semiarid Rangelands Under Different Environmental Settings

Rangelands play a crucial socioeconomic and environmental role worldwide. In South America, desertification and overgrazing has led to their deterioration and declining productivity. Breeding programs that use native forage species of economic and ecological importance, such as Festuca pallescens (St. Yves) Parodi, may provide locally adapted germplasm that enhances productivity without threatening local biodiversity. These programs may even promote the conservation of native species. To this end, we characterized the phenotypic variation of nondestructive variables (growth and reproductive traits) related to forage and seed production during spring and early summer (growth and reproductive periods). Plants from ten populations were grown under common garden conditions in two environmental settings (sites) over two years. By early summer of the second year, most populations maintained a consistent relative performance with higher values for basal diameter, height and synflorescence production at site 2. This suggests more favorable environmental conditions for the species and highlights their potential for enhancing both seed and forage production. The growth and reproductive traits were probably largely influenced by micro-environmental cues (i.e., soil type and moisture), showing predominantly plastic patterns. The populations displaying phenotypic plasticity and above-average values for both traits were selected for further evaluation in breeding programs.

Vitamin application affects gas exchange, growth, and yield of soybean plants

The application of biostimulants in agriculture has been used to increase crop yield. This study evaluated the effects of exogenous application of thiamine and nicotinamide on soybean plants. The experiment was conducted in Cassilândia, MS. The randomized blocks design with 5 treatments and 8 replications was used. The treatments consisted of concentrations of nicotinamide and thiamine at 0, 50, and 100 mg L-1 of water, applied exogenously when the plants were at the V3 stage. Gas exchange, number of grains per pod, number of pods, and grain yield were assessed. Plant height was increased by applying vitamins, with all treatments outperforming the control. The application of nicotinamide or thiamine at doses between 50 and 100 mg L-1 favors the development and grain yield of soybean plants, making it possible to use them as a biostimulant.

Navigating Climate Change: Exploring the Dynamics Between Plant-Soil Microbiomes and Their Impact on Plant Growth and Productivity

Understanding the intricate interplay between plant and soil microbiomes and their effects on plant growth and productivity is vital in a rapidly changing climate. This review explores the interconnected impacts of climate change on plant-soil microbiomes and their profound effects on agricultural productivity. The ongoing rise in global temperatures, shifting precipitation patterns and extreme weather events significantly affect the composition and function of microbial communities in the rhizosphere. Changes in microbial diversity and activity due to rising temperatures impact nutrient cycling, microbial enzyme synthesis, soil health and pest and disease management. These changes also influence the dynamics of soil microbe communities and their capability to promote plant health. As the climate changes, plants' adaptive capacity and microbial partners become increasingly crucial for sustaining agriculture. Mitigating the adverse effects of climate change on plant growth and agricultural productivity requires a comprehensive understanding of the interconnected mechanisms driving these processes. It highlights various strategies for mitigating and adapting to environmental challenges, including soil management, stress-tolerant crops, cover cropping, sustainable land and water management, crop rotation, organic amendments and the development of climate-resilient crop varieties. It emphasises the need for further exploration of plant-soil microbiomes within the broader context of climate change. Promising mitigation strategies, including precision agriculture and targeted microbiome modifications, offer valuable pathways for future research and practical implementation of global food security and climate change.

Small non-coding satellite RNAs - the 'game changers' at the virus-host plant interaction?

Satellite RNAs (satRNAs) are RNA molecules associated with many plant viruses and fully dependent on them for replication, encapsidation, and movement within the plant or transmission from plant to plant. Their classification is based on their length, functional protein-coding capacity, and RNA structure (whether linear or circular). They have been of interest for a long time as some of them, in particular systems, cause significant changes in the pathogenesis and epidemiology of plant viruses. The outcomes of how satRNAs affect pathogenesis depend on the components of the pathosystem: host plant species or variety, virus species or even strain, and the sequence of satRNA. These can be additionally affected by biotic and abiotic factors, for example, environmental conditions such as the presence of their vectors or ambient temperature. satRNAs may interfere with primary metabolism, signalling, plant defence [including post-transcriptional gene silencing (PTGS)], as well as the efficiency of virus transmission from plant to plant. In recent years, due to wider access to high-throughput technologies and the extension of studies on satRNAs to include the involvement of external factors in plant-virus-satRNA systems, we are gaining a broader view of the consequences of the presence of these small molecules in viral infections. This review presents the state of the art of satRNA interactions with the helper virus and host plant as well as the influence of satRNAs on the insect vector's behaviour. Moreover, areas requiring further research are identified and knowledge gaps indicated.

Do different wheat ploidy levels respond differently against stripe rust infection: Interplay between reactive oxygen species (ROS) and the antioxidant defense system?

Wheat stripe rust (Puccinia striiformis f. sp. tritici, Pst) is the most damaging wheat disease, causing substantial losses in global wheat production and productivity. Our study aimed to unravel the complex reciprocity between reactive oxygen species and the antioxidant defense system as a source of resistance against stripe rust in diploid, tetraploid and hexaploid wheat genotypes. The significant genetic variability for stripe rust in the materials under study was evident as the genotypes showed contrasting responses during both the adult and seedling stages. Our thorough perspective on the biochemical responses of wheat genotypes to stripe rust infection revealed distinct patterns in oxidative damage, antioxidant enzymes and photosynthetic pigments. Principal component analysis revealed inverse correlations between antioxidants and ROS, underscoring their key function in maintaining the cellular redox balance and protecting plants against oxidative damage. Diploid (Ae. tauschii) wild wheat exhibited a better biochemical defense system and greater resistance to stripe rust than the tetraploid (T. durum) and hexaploid (Triticum aestivum) wheat genotypes. The antioxidant enzyme activity of durum wheat was moderate compared to diploid and hexaploid wheat genotypes. The hexaploid wheat genotypes exhibited increased ROS production, reduced antioxidant enzyme activity and decreased photosynthetic pigment levels. This study enhances understanding of the antioxidant defense system across different wheat ploidies facing stripe rust, serving as a valuable strategy for improving crop disease resistance. This study validated the biochemical response of stripe rust-resistant and susceptible candidate genotypes, which will be used to develop genetic resources for discovering stripe rust resistance genes in wheat.

Molecular docking and differential rbcl gene expression reveal variation in glyphosate herbicide tolerance of sugarcane varieties

BACKGROUND

Glyphosate is an extensively employed herbicide in agriculture, specifically for sugarcane cultivation. The situation is different with the extensive physiological and genetic effects exerted by this herbicide on a range of plant species, including sugarcane, whose model basis is still poorly characterized, although its primary mode of action, which acts on the EPSPS enzyme in the shikimic acid pathway, is completely elucidated. The current study was aimed at investigating the stability of glyphosate formulation, molecular interactions of glyphosate formulation with rbcL enzyme associated with chlorophyll metabolism, and its effects on varieties of sugarcane.

METHODS AND RESULTS

The stability of a ground-up glyphosate formulation was assessed under accelerated storage conditions. Molecular docking was performed to analyze interactions between glyphosate derivatives and rbcL. Two sugarcane varieties (G84-47 and GT54-9) were treated with increasing glyphosate concentrations (0.2, 0.4, and 0.8 mg L-1) to evaluate effects on chlorophyll content, plant height, herbicide tolerance, and rbcL expression. The formulation showed good stability with minor degradation (47.55-47.14%). N-Nitrosoglyphosate and 2-(phosphonomethylamino)acetic acid exhibited favorable binding affinities with rbcL. Glyphosate treatment reduced chlorophyll content and plant height dose-dependently, with G84-47 showing higher sensitivity. GT54-9 demonstrated higher herbicide tolerance in survival analysis. rbcL expression remained stable in G84-47 but was significantly upregulated in GT54-9 under high herbicide stress.

CONCLUSIONS

This study reveals genetic variability in sugarcane responses to glyphosate, with variety-specific mechanisms underlying stress adaptation. The inducible rbcL expression in tolerant varieties provides insights into herbicide resistance mechanisms. These findings can inform marker-assisted breeding and improve agronomic practices for enhanced sugarcane cultivation resilience and sustainability.

Climate Change and Plant Foods: The Influence of Environmental Stressors on Plant Metabolites and Future Food Sources

Climate change is reshaping global agriculture by altering temperature regimes and other environmental conditions, with profound implications for food security and agricultural productivity. This review examines how key environmental stressors-such as extreme temperatures, water scarcity, increased salinity, UV-B radiation, and elevated concentrations of ozone and CO2-impact the nutritional quality and bioactive compounds in plant-based foods. These stressors can modify the composition of essential nutrients, particularly phytochemicals, which directly affect the viability of specific crops in certain regions and subsequently influence human dietary patterns by shifting the availability of key food resources. To address these challenges, there is growing interest in resilient plant species, including those with natural tolerance to stress and genetically modified variants, as well as in alternative protein sources derived from plants. Additionally, unconventional food sources, such as invasive plant species and algae, are being explored as sustainable solutions for future nutrition.

Deciphering of Genomic Loci Associated with Alkaline Tolerance in Soybean [Glycine max (L.) Merr.] by Genome-Wide Association Study

Alkaline stress is one of the major abiotic constraints that limits plant growth and development. However, the genetic basis underlying alkaline tolerance in soybean [Glycine max (L.) Merr.] remains largely unexplored. In this study, an integrated genomic analysis approach was employed to elucidate the genetic architecture of alkaline tolerance in a diverse panel of 326 soybean cultivars. Through association mapping, we detected 28 single nucleotide polymorphisms (SNPs) significantly associated with alkaline tolerance. By examining the genomic distances around these significant SNPs, five genomic regions were characterized as stable quantitative trait loci (QTLs), which were designated as qAT1, qAT4, qAT14, qAT18, and qAT20. These QTLs are reported here for the first time in soybean. Seventeen putative candidate genes were identified within the physical intervals of these QTLs. Haplotype analysis indicated that four of these candidate genes exhibited significant allele variation associated with alkaline tolerance-related traits, and the haplotype alleles for these four genes varied in number from two to four. The findings of this study may have important implications for soybean breeding programs aimed at enhancing alkaline tolerance.

Megoura crassicauda promote the ability of Vicia faba L. to remediate cadmium pollution of water and soil

With the increasing severity of heavy metal pollution in soil and water, phytoremediation is becoming increasingly popular because of its low cost, high returns, and environmental friendliness. The use of leguminous plants such as the broad bean for heavy metal remediation is becoming a research hotspot because of their symbiotic relationship with rhizobia. This study investigated the cadmium (Cd) remediation ability of fava beans by M. crassicauda feeding on or not using both hydroponic and soil cultures containing varying concentrations of Cd. Under hydroponic conditions, the Cd content in fava beans increased significantly following aphid invasion. while the Cd content decreased after aphid infestation under soil cultivation conditions. Aphid infestation significantly decreased the Cd content in both soil and hydroponic solution. However, there were no significant changes in germination rate and phenotype. We also found that prolonged Cd treatment increased the activities of stress-related antioxidant enzymes in fava beans, including superoxide dismutase, peroxidase, and malondialdehyde. After consumption by M. crassicauda, the levels of total sugar content underwent varying changes. These results demonstrate that fava beans not only exhibit high Cd tolerance but can also effectively absorb Cd ions from soil and water. Moreover, pest infestation can enhance broad bean remediation efficiency, making them potential targets for use in the phytoremediation of heavy metal pollution.

Understanding the impacts of drought on peanuts (Arachis hypogaea L.): exploring physio-genetic mechanisms to develop drought-resilient peanut cultivars

Peanut is a vital source of protein, particularly in the tropical regions of Asian and African countries. About three-quarters of peanut production occurs worldwide in arid and semi-arid regions, making drought an important concern in peanut production. In the US about two-thirds of peanuts are grown in non-irrigated lands, where drought accounts for 50 million USD loss each year. The looming threat of climate change exacerbates this situation by increasing erratic rainfall. Drought not only reduces yield but also degrades product quality. Peanuts under drought stress exhibit higher levels of pre-harvest aflatoxin contamination, a toxic fungal metabolite detrimental to both humans and animals. One way to sustain peanut production in drought-prone regions and address pre-harvest aflatoxin contamination is by developing drought-tolerant peanut cultivars, a process that can be accelerated by understanding the underlying physiological and genetic mechanisms for tolerance to drought stress. Different physiological attributes and genetic regions have been identified in drought-tolerant cultivars that help them cope with drought stress. The advent of precise genetic studies, artificial intelligence, high-throughput phenotyping, bioinformatics, and data science have significantly improved drought studies in peanuts. Yet, breeding peanuts for drought tolerance is often a challenge as it is a complex trait significantly affected by environmental conditions. Besides technological advancements, the success of drought-tolerant cultivar development also relies on the identification of suitable germplasm and the conservation of peanut genetic variation.

Phenotypic plasticity does not prevent impairment of aboveground biomass production due to increased light and water deficit in Dimorphandra exaltata, an endangered species

Phenotypic plasticity may allow plant species to cope with environmental variability that influences plant growth and may limit the distribution of a species. The present study investigated the morphophysiology and phenotypic plasticity responses due to light and water variability of young Dimorphandra exaltata plants, an endemic threatened tree from the Atlantic Forest. After emergence, plants were grown in two light conditions: shading (70%) and full sun. At 160 days old, we measured chlorophyll a fluorescence, chlorophyll indices, and biomass allocation. Afterward, the plants were subdivided into two water regimes: irrigation vs suspension of irrigation. At 310 days old, morphophysiological measurements and stem water potential were taken. D. exaltata plants showed higher specific leaf area (SLA, 160 days old) and chlorophyll b (310 days old) under shading. Over time, plants under shading showed a decrease in SLA. Also, there was a decrease in the leaf area ratio in both light treatments and an increase in the phenotypic plasticity index. Even showing morphological adjustments to light and water deficit, the higher biomass allocation to roots at the expense of the aboveground part could impair the growth of young plants in understory areas. The phenotypic plasticity presented by D. exaltata does not guarantee that the species can withstand severe disturbance while maintaining normal development. Therefore, it is important to understand the effects of ecosystem fragmentation and water variation and their impacts on the maintenance of species in their areas of occurrence, especially endangered species such as D. exaltata.

A Chimeric Peptide for Shielding Plant Photosynthetic Systems against Excess Light Stress via Chloroplast-Targeted ROS Quenching

The ability to quench reactive oxygen species (ROS) overproduced in plant chloroplasts under light stress conditions is essential for securing plant photosynthetic performance and agricultural yield. Although genetic engineering can enhance plant stress resistance, its widespread application faces limitations due to challenges in successful transformation across plant species and public acceptance concerns. This study proposes a nontransgenic chemical approach using a designed chimeric peptide that scavenges ROS within plant chloroplasts for managing light stress. The chimeric peptide was strategically designed by combining cell-penetrating and chloroplast-targeting sequences, each with antioxidant ability against destructive ROS such as hydroxyl radical (•OH) and singlet oxygen (1O2). Our analyses involving various cell-penetrating peptides and a chloroplast-targeting peptide revealed that the •OH-scavenging ability predominantly relied on side chain oxidation in tryptophan residues, while the 1O2-quenching capacity was attributed to the oxidation of cysteine and methionine side chains. We further demonstrated that the chimeric peptide could traverse the cell wall and membranes to reach chloroplasts, where it scavenged •OH and 1O2 and alleviated light-stress-induced chlorophyll degradation in leaves. Foliar spraying of the peptide successfully protected photosynthetic activity in leaves exposed to excessive light, highlighting its potential for practical agricultural applications. This work can offer a promising approach for managing abiotic stress without genetic modifications and provide valuable insights into the design of effective peptide-based ROS quenchers specifically targeting plant chloroplasts.

Harnessing Single-Cell and Spatial Transcriptomics for Crop Improvement

Single-cell and spatial transcriptomics technologies have significantly advanced our understanding of the molecular mechanisms underlying crop biology. This review presents an update on the application of these technologies in crop improvement. The heterogeneity of different cell populations within a tissue plays a crucial role in the coordinated response of an organism to its environment. Single-cell transcriptomics enables the dissection of this heterogeneity, offering insights into the cell-specific transcriptomic responses of plants to various environmental stimuli. Spatial transcriptomics technologies complement single-cell approaches by preserving the spatial context of gene expression profiles, allowing for the in situ localization of transcripts. Together, single-cell and spatial transcriptomics facilitate the discovery of novel genes and gene regulatory networks that can be targeted for genetic manipulation and breeding strategies aimed at enhancing crop yield, quality, and resilience. This review highlights significant findings from recent studies, discusses the expanding roles of these technologies, and explores future opportunities for their application in crop improvement.

Tobacco production under global climate change: combined effects of heat and drought stress and coping strategies

With the intensification of global climate change, high-temperature and drought stress have emerged as critical environmental stressors affecting tobacco plants' growth, development, and yield. This study provides a comprehensive review of tobacco's physiological and biochemical responses to optimal temperature conditions and limited irrigation across various growth stages. It assesses the effects of these conditions on yield and quality, along with the synergistic interactions and molecular mechanisms associated with these stressors. High-temperature and drought stress induces alterations in both enzymatic and non-enzymatic antioxidant activities, lead to the accumulation of reactive oxygen species (ROS), and promote lipid peroxidation, all of which adversely impact physiological processes such as photosynthetic gas exchange, respiration, and nitrogen metabolism, ultimately resulting in reduced biomass, productivity, and quality. The interaction of these stressors activates novel plant defense mechanisms, contributing to exacerbated synergistic damage. Optimal temperature conditions enhance the activation of heat shock proteins (HSPs) and antioxidant-related genes at the molecular level. At the same time, water stress triggers the expression of genes regulated by both abscisic acid-dependent and independent signaling pathways. This review also discusses contemporary agricultural management strategies, applications of genetic engineering, and biotechnological and molecular breeding methods designed to mitigate adverse agroclimatic responses, focusing on enhancing tobacco production under heat and drought stress conditions.

Molecular Communication of Microbial Plant Biostimulants in the Rhizosphere Under Abiotic Stress Conditions

Microbial plant biostimulants offer a promising, sustainable solution for enhancing plant growth and resilience, particularly under abiotic stress conditions such as drought, salinity, extreme temperatures, and heavy metal toxicity. These biostimulants, including plant growth-promoting rhizobacteria, mycorrhizal fungi, and nitrogen-fixing bacteria, enhance plant tolerance through mechanisms such as phytohormone production, nutrient solubilization, osmotic adjustment, and antioxidant enzyme activation. Advances in genomics, metagenomics, transcriptomics, and proteomics have significantly expanded our understanding of plant-microbe molecular communication in the rhizosphere, revealing mechanisms underlying these interactions that promote stress resilience. However, challenges such as inconsistent field performance, knowledge gaps in stress-related molecular signaling, and regulatory hurdles continue to limit broader biostimulant adoption. Despite these challenges, microbial biostimulants hold significant potential for advancing agricultural sustainability, particularly amid climate change-induced stresses. Future studies and innovation, including Clustered Regularly Interspaced Short Palindromic Repeats and other molecular editing tools, should optimize biostimulant formulations and their application for diverse agro-ecological systems. This review aims to underscore current advances, challenges, and future directions in the field, advocating for a multidisciplinary approach to fully harness the potential of biostimulants in modern agriculture.

Sublethal effects of nanoformulated Mentha pulegium L. essential oil on the biological and population growth parameters of the greenhouse whitefly, Trialeurodes vaporariorum, (Hemiptera: Aleyrodidae)

We evaluated the toxicity and sublethal effects of essential oil (Mentha pulegium L.) and its nanoformulation against greenhouse whitefly, Trialeurodes vaporariorum, which is one of the most destructive pests of a wide range of crops. The essential oil was extracted from the plant by steam distillation using a Clevenger apparatus, and 14 chemical components of M. pulegium were identified using gas chromatography-mass spectrometry. The results illustrated that monoterpenoids were main characterized components including pulegone (%66), menthofren (%10.54), 1, 8 Cineole (%8.36), betapenin (%3.49) and limonene (%2.01). The nanoformulation was characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM), revealing that the particles were spherical in shape with an average size of 156.40 nm. The leaf dipping was used for the bioassays. The obtained LC50 and LC25 values of treatments indicated that the nanoformulation of essential oil (LC50: 2418.96 and LC25: 1724. 25 ppm) was more toxic than the pure of M. pulegium oil (LC50: 3223.083 and LC25: 779.439 ppm ppm) against greenhouse whitefly adults after 24 h. The life table data were analyzed based on the age-stage, two-sex life table theory using computer program of TWOSEX-MSChart. Also, the sublethal concentration (LC25) of its nanoformulation led to delaying in preadult stage and decreased the adult longevity, and fecundity compared to treatments. Moreover, the sublethal concentration of either M. pulegium oil or its nanoformulation affected the population growth parameters of T.vaporariorum compared to the control. However, the net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), of adults who exposed to the nanoformulation was lower than the pure form of M. pulegium. The overall results demonstrated that the nanoformulation of M. pulegium has the most lethal and sublethal effects on greenhouse whitefly compared with the pure form of essential oil which can be consider in integrated pest management program (IPM) of this pest.

Genome-Wide Analysis of HECT E3 Ligases Members in Phyllostachys edulis Provides Insights into the Role of PeHECT1 in Plant Abiotic Stress Response

Homology to E6-AP Carboxy Terminus (HECT) E3 ubiquitin ligases play pivotal roles in plant growth, development, and responses to abiotic stresses. However, the function of HECT genes in Phyllostachys edulis (P. edulis) remains largely uninvestigated. In this study, a comprehensive genome-wide analysis of the HECT E3 ubiquitin ligases gene family in P. edulis was conducted, aiming to elucidate its evolutionary relationships and gene expansion. Analysis of gene structure, conserved motifs and domains, and synteny genome regions were performed. Furthermore, cis-elements in HECT gene promoters that respond to plant hormones and environmental stresses were identified and corroborated by expression data from diverse abiotic stress conditions and hormone treatments. Based on the co-expression network of PeHECTs under cold and dehydration stresses, PeHECT1 was identified as a key candidate gene associated with abiotic stress tolerance. Overexpression of PeHECT1 in tobacco leaves significantly upregulated genes related to reactive oxygen species (ROS) detoxification and polyamine biosynthesis. Yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA), and dual-luciferase (dual-LUC) assays suggested that the transcription factor ETHYLENE RESPONSE FACTOR 3 (PeERF3) bound to the dehydration-responsive element (DRE) of the promoter of PeHECT1 and activated its transcription activity. Phylogenetic analysis indicated that PeHECT1 in P. edulis exhibited a close association with the diploid herbaceous bamboo Olyra latifolia, followed by the divergence of rice and bamboo. In summary, this study enhances our comprehensive understanding of the HECT E3 ubiquitin ligases gene family in P. edulis and highlights the potential role of PeHECT1 in plant abiotic stress response.

Identification and analysis of flavonoid pathway genes in responsive to drought and salinity stress in Medicago truncatula

Flavonoid compounds are widely present in various organs and tissues of different plants, playing important roles when plants are exposed to abiotic stresses. Different types of flavonoids are biosynthesized by a series of enzymes that are encoded by a range of gene families. In this study, a total of 63 flavonoid pathway genes were identified from the genome of Medicago truncatula. Gene structure analysis revealed that they all have different gene structure, with most CHS genes containing only one intron. Additionally, analysis of promoter sequences revealed that many cis-acting elements responsive to abiotic stress are located in the promoter region of flavonoid pathway genes. Furthermore, analysis on M. truncatula gene chip data revealed significant changes in expression level of most flavonoid pathway genes under the induction of salt or drought treatment. qRT-PCR further confirmed significant increase in expression level of several flavonoid pathway genes under NaCl and mannitol treatments, with CHS1, CHS9, CHS10, F3'H4 and F3'H5 genes showing significant up-regulation, indicating they are key genes in response to abiotic stress in M. truncatula. In summary, our study identified key flavonoid pathway genes that were involved in salt and drought response, which provides important insights into possible modification of flavonoid pathway genes for molecular breeding of forage grass with improved abiotic resistance.

Enhancing cold tolerance in tobacco through endophytic symbiosis with Piriformospora indica

Tobacco, a warm-season crop originating from the Americas, is highly susceptible to cold stress. The utilization of symbiotic fungi as a means to bolster crops' resilience against abiotic stresses has been proven to be a potent strategy. In this study, we investigated the effect of endophytic fungus Piriformospora indica on the cold resistance of tobacco. When exposed to cold stress, the colonization of P.indica in tobacco roots effectively stimulates the activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX). This, in turn, reduces the accumulation of reactive oxygen species (ROS), thereby mitigating oxidative damage. Additionally, P. indica elevates the levels of osmolytes, such as soluble sugars, proline, and soluble proteins, thus facilitating the restoration of osmotic balance. Under cold stress conditions, P. indica also induces the expression of cold-responsive genes. Furthermore, this fungus not only enhances photosynthesis in tobacco by stimulating the synthesis of photosynthetic pigments, strengthening Rubisco activity, and elevating PSII efficiency, but also fortifies tobacco's nitrogen assimilation by inducing the expression of nitrate transporter gene and activating enzymes related to nitrogen assimilation. Consequently, this synergistic optimization of nitrogen and carbon assimilation provides a solid material and energetic foundation for tobacco plants to withstand cold stress. Our study demonstrates that a mycorrhizal association between P. indica and tobacco seedlings provides multifaceted protection to tobacco plants against low-temperature stress and offers a valuable insight into how P. indica enhances the cold tolerance of tobacco.

Seasonal influence on tomato fruit metabolome profile: Implications for ABA signaling in multi-stress resilience

The increasing effects of climate change are leading to an increase in the number and intensity of extreme events, making it essential to study how plants respond to various stresses occurring simultaneously. A crucial regulator of plant responses to abiotic stress is abscisic acid (ABA), as its accumulation in response to stress leads to transcriptomic and metabolomic changes that contribute to plant stress tolerance. In the present study, we investigated how ABA, stress conditions (salinity, water deficit and their combination) and seasons (autumn-winter and spring-summer) regulate tomato fruit yield and metabolism using tomato wild type (WT) and the ABA-deficient flacca mutant (flc) under stress conditions in cold and warm seasons. Our results showed that the applied stresses did not have the same effect in the warm season as in the cold season. In WT plants, the levels of other flavonoids, lignans and other polyphenols were higher in summer fruits, whereas the levels of anthocyanins, flavanols, flavonols, phenolic acids and stilbenes were higher in winter fruits. Furthermore, the significant increase in anthocyanins and flavonols was associated with the combination of salinity + water deficit in both seasons. Additionally, under certain conditions, flc mutants showed an enrichment of the superclasses of benzenoids and organosulphur compounds. The synthesis of phenolic compounds in flc fruits was also significantly different compared to WT plants. Thus, the metabolic profile of tomato fruits varies significantly with endogenous ABA levels, season of cultivation and applied stress treatments, highlighting the multifactorial nature of plant responses to combined environmental factors.

Chili cultivars vulnerability: a multi-factorial examination of disease and pest-induced yield decline across different growing microclimates and watering regimens

BACKGROUND

As identified by the research, it is imperative to develop effective ways to address the pressing problem of disease and pest susceptibility in chili agriculture and secure sustainable crop yield. The research examines the impact of various growing microclimates, watering regimens, and chili cultivars on disease incidence, pest attacks, and yield loss.

RESULTS

The study, which took place over a season, used a randomized complete block design to evaluate how well Tanjung, Unpad, and Osaka cultivars performed in four different watering regimens (100, 75, 50, and 25% ETc) and different microclimates (greenhouse, rain shelter, screen house, and open field). The findings exhibited that watering regimens and microclimates greatly influenced disease and pest occurrence, but cultivars had a minimal effect on these variables. Disease and pest attack rates were highest in the open field and lowest in the screen house. A correlation was found between lower disease and pest incidence and optimal irrigation levels (75% and 100% ETc). At lower watering regimens of 25% ETc and in the open field, yield loss was the greatest.

CONCLUSION

The results emphasize how crucial controlled environments and appropriate irrigation techniques are to reducing crop loss and increasing production. Enhancing watering regimens and implementing screen house cultivation are two strategies for improving the productivity and sustainability of chili output.

Unveiling Temperature-Induced Structural Phase Transformations and CO2 Binding Sites in CALF-20

The increase in atmospheric carbon dioxide concentration linked to climate change has created a need for new sorbents capable of separating CO2 from exhaust gases. Recently, an easily produced metal-organic framework, CALF-20, was shown to withstand over 450,000 adsorption/desorption cycles in steam and wet acid gases. Further development and industrial application of such materials require an understanding of the observed processes. Herein, we demonstrate that conditioning as-synthesized CALF-20 single crystal transforms it into a different phase, γ-CALF-20. The transformation resulted in significant structural changes, including the binding of water molecules to Zn(II), accompanied by a reduction of 9% in the unit cell volume. Our experimental findings were supported by the energy-volume dependence of CALF-20 in the presence and absence of water molecules calculated from density functional theory. We have also monitored the sorption process of the dominant greenhouse gas, CO2, on the initial phase of CALF-20 at atomic resolution using in situ single-crystal X-ray diffraction under specific pressure. The new understanding of CALF-20 chemistry from these studies should facilitate development of novel sorbents for gas adsorption technologies.

Xanthium strumarium L., an invasive species in the subtropics: prediction of potential distribution areas and climate adaptability in Pakistan

Invasive species such as Xanthium strumarium L., can disrupt ecosystems, reduce crop yields, and degrade pastures, leading to economic losses and jeopardizing food security and biodiversity. To address the challenges posed by invasive species such as X. strumarium, this study uses species distribution modeling (SDM) to map its potential distribution in Pakistan and assess how it might respond to climate change. This addresses the urgent need for proactive conservation and management strategies amidst escalating ecological threats. SDM forecasts a species' potential dispersion across various geographies in both space and time by correlating known species occurrences to environmental variables. SDMs have the potential to help address the challenges posed by invasive species by predicting the future habitat suitability of species distributions and identifying the environmental factors influencing these distributions. Our study shows that seasonal temperature dependence, mean temperature of wettest quarter and total nitrogen content of soil are important climatic factors influencing habitat suitability of X. strumarium. The potential habitat of this invasive species is likely to expand beyond the areas it currently colonizes, with a notable presence in the Punjab and Khyber Pakhtunkhwa regions. These areas are particularly vulnerable due to threats to agriculture and biodiversity. Under current conditions, an estimated 21% of Pakistan's land area is infested by X. strumarium, mainly in upper Punjab, central Punjab and Khyber Pakhtunkhwa. The range is expected to expand in most regions except Sindh. The central and northeastern parts of the country are proving to be particularly suitable habitats for X. strumarium. Effective strategies are crucial to contain the spread of X. strumarium. The MaxEnt modeling approach generates invasion risk maps by identifying potential risk zones based on a species' climate adaptability. These maps can aid in early detection, allowing authorities to prioritize surveillance and management strategies for controlling the spread of invasive species in suitable habitats. However, further research is recommended to understand the adaptability of species to unexplored environments.

Comparative Insights into Photosynthetic, Biochemical, and Ultrastructural Mechanisms in Hibiscus and Pelargonium Plants

Understanding photosynthetic mechanisms in different plant species is crucial for advancing agricultural productivity and ecological restoration. This study presents a detailed physiological and ultrastructural comparison of photosynthetic mechanisms between Hibiscus (Hibiscus rosa-sinensis L.) and Pelargonium (Pelargonium zonale (L.) L'Hér. Ex Aiton) plants. The data collection encompassed daily photosynthetic profiles, responses to light and CO2, leaf optical properties, fluorescence data (OJIP transients), biochemical analyses, and anatomical observations. The findings reveal distinct morphological, optical, and biochemical adaptations between the two species. These adaptations were associated with differences in photochemical (AMAX, E, Ci, iWUE, and α) and carboxylative parameters (VCMAX, ΓCO2, gs, gm, Cc, and AJMAX), along with variations in fluorescence and concentrations of chlorophylls and carotenoids. Such factors modulate the efficiency of photosynthesis. Energy dissipation mechanisms, including thermal and fluorescence pathways (ΦPSII, ETR, NPQ), and JIP test-derived metrics highlighted differences in electron transport, particularly between PSII and PSI. At the ultrastructural level, Hibiscus exhibited optimised cellular and chloroplast architecture, characterised by increased chloroplast density and robust grana structures. In contrast, Pelargonium displayed suboptimal photosynthetic parameters, possibly due to reduced thylakoid counts and a higher proportion of mitochondria. In conclusion, while Hibiscus appears primed for efficient photosynthesis and energy storage, Pelargonium may prioritise alternative cellular functions, engaging in a metabolic trade-off.

Molecular and agro-morphological diversity assessment of some bread wheat genotypes and their crosses for drought tolerance

Wheat, a staple cereal crop, faces challenges due to climate change and increasing global population. Maintaining genetic diversity is vital for developing drought-tolerant cultivars. This study evaluated the genetic diversity and drought response of five wheat cultivars and their corresponding F1 hybrids under well-watered and drought stress conditions. Molecular profiling using ISSR and SCoT-PCR markers revealed 28 polymorphic loci out of 76 amplified. A statistically significant impact of parental genotypes and their crosses was observed on all investigated agro-morphological traits, including root length, root weight, shoot length, shoot weight, proline content, spikelet number/spike, spike length, grain number/spike, and grain weight/spike. The parental genotypes P1 and P3 had desirable positive and significant general combining ability (GCA) effects for shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, shoot length, and root length under well-watered conditions, while P3 and P5 recorded the highest GCA estimates under drought stress. P3 and P4 showed the highest GCA effects for number of spikelets per spike, the number of grains per spike, and grain weight per spike under normal conditions. P5 presented the maximum GCA effects and proved to be the best combiner under drought stress conditions. The cross P1× P3 showed the highest positive specific combining ability (SCA) effects for shoot fresh weight under normal conditions, while P2×P3 excelled under water deficit conditions. P1× P2, P1 × P3, and P4× P5 were most effective for shoot dry weight under normal conditions, whereas P1×P3 and P3×P5 showed significant SCA effects under drought stress. Positive SCA effects for root fresh weight and shoot length were observed for P3×P5 under stressed conditions. Additionally, P4×P5 consistently recorded the highest SCA for root length in both environments, and P3×P5 excelled in the number of spikelets, grains per spike, and grain weight per spike under drought conditions. The evaluated genotypes were categorized based on their agronomic performance under drought stress into distinct groups ranging from drought-tolerant genotypes (group A) to drought-sensitive ones (group C). The genotypes P5, P2×P5, and P3×P5 were identified as promising genotypes to improve agronomic performance under water deficit conditions. The results demonstrated genetic variations for drought tolerance and highlighted the potential of ISSR and SCoT markers in wheat breeding programs for developing drought-tolerant cultivars.

Be prepared: how does discontinuous hydration in Tabebuia heterophylla seeds induce stress tolerance in seedlings?

Discontinuous hydration and dehydration (HD) cycles refer to controlled imbibition followed by dehydration before seed germination. Here, we investigated whether the level of imbibition before HD cycles affects the physiology of Tabebuia heterophylla seeds and seedlings. Seeds were imbibed for 10 h (T1; phase I of imbibition) or 35 h (T2; phase II), dehydrated, and progressively rehydrated one to four times (HD cycles). Germination and biochemical parameters (membrane integrity; total soluble, reducing, and nonreducing (NRS) sugars; proteins, amino acids, proline, H2O2, catalase, ascorbate peroxidase, and glutathione reductase activity) were quantified at the last rehydration step of each cycle. Biometric and biochemical parameters (including pigments) were analysed in seedlings 60 days after germination. HD cycles at T1 led to reduced seed germination and greater plasma membrane damage, higher enzyme activity (catalase and glutathione reductase) and accumulation of NRS, total amino acids, and proline compared to the controls and T2 treatment. Cellular damage became more severe with more HD cycles. HD cycles at T2 synchronized germination regardless of the number of cycles and also had a priming effect. T2 seeds had less NRS, total amino acids, and proline content than T1. HD cycles at T1 produced seedlings with higher carotenoid and total chlorophyll content than controls and T2, while seedlings from HD cycles at T2 had higher amounts of osmoprotectants. HD cycles at T2 benefited seeds and seedlings more than at T1. This suggests that the physiological and biochemical effects of HD cycles in seeds modulate seedling plasticity, depending on water availability, potentially promoting increased tolerance to recurrent droughts that will be intensified with ongoing climate changes.

Three cassava A20/AN1 family genes, Metip3 (5, and 7), can bestow on tolerance of plants to multiple abiotic stresses but show functional convergence and divergence

A20/AN1 zinc-finger domain-containing genes are very promising candidates in improving plant tolerance to abiotic stresses, but considerably less is known about functions and mechanisms for many of them. In this study, Metip3 (5, and 7), cassava (Manihot esculenta) A20/AN1 genes carrying one A20 domain and one AN1 domain, were functionally characterized at different layers. Metip3 (5, and 7) proteins were all located in the nucleus. No interactions were found between these three proteins. Metip3 (5, and 7)-expressing Arabidopsis was more tolerant to multiple abiotic stresses by Na, Cd, Mn, Al, drought, high temperature, and low temperature. Metip3- and Metip5-expressing Arabidopsis was sensitive to Cu stress, while Metip7-expressing Arabidopsis was insensitive. The H2O2 production significantly decreased in all transgenic Arabidopsis, however, O2·- production significantly decreased in Metip3- and Metip5-expressing Arabidopsis but did not significantly changed in Metip7-expressing Arabidopsis under drought. Metip3 (5, and 7) expression-silenced cassava showed the decreased tolerance to drought and NaCl, presented significant decreases in superoxide dismutase and catalase activities and proline content, and displayed a significant increase in malondialdehyde content under drought. Taken together with transcriptome sequencing analysis, it is suggested that Metip5 gene can not only affect signal transduction related to plant hormone, mitogen activated protein kinases, and starch and sucrose metabolism, DRE-binding transcription factors, and antioxidants, conferring the drought tolerance, but also might deliver the signals from DREB2A INTERACTING PROTEIN1, E3 ubiquitin-protein ligases to proteasome, leading to the drought intolerance. The results are informative not only for further study on evolution of A20/AN1 genes but also for development of climate resilient crops.

Unravelling the Epigenetic Code: DNA Methylation in Plants and Its Role in Stress Response

Environmental stress significantly affects plant growth, development, and survival. Plants respond to stressors such as temperature fluctuations, water scarcity, nutrient deficiencies, and pathogen attacks through intricate molecular and physiological adaptations. Epigenetic mechanisms are crucial in regulating gene expression in response to environmental stress. This review explores the current understanding of epigenetic modifications, including DNA methylation, and their roles in modulating gene expression patterns under environmental stress conditions. The dynamic nature of epigenetic modifications, their crosstalk with stress-responsive pathways, and their potential implications for plant adaptation and crop improvement are highlighted in the face of changing environmental conditions.

High photosynthetic thermal tolerance in the Mediterranean halophyte Limoniastrum monopetalum

The general increase in temperature, together with sudden episodes of extreme temperatures, are increasingly impacting plant species in the present climate change scenario. Limoniastrum monopetalum is a halophyte from the Mediterranean Basin, exposed to broad daily and seasonal changes in temperature and extreme high temperatures. We studied the photosynthetic responses (chlorophyll fluorescence dynamics and gas exchange) of L. monopetalum leaves exposed to temperatures from -7.5°C to +57.5°C under darkness in controlled laboratory conditions. L. monopetalum presented its optimum temperature for photosynthesis around +30°C. The photosynthetic apparatus of L. monopetalum exhibited permanent damages at > +40.0°C. L. monopetalum tolerated, without permanent damages, temperatures as low as -7.5°C in darkness. L. monopetalum appears as a plant species very well adapted to the seasonality of the Mediterranean climate, which may work as a pre-adaptation to stand more extreme temperatures in the actual context of accelerating climate change.

Partial root-zone drying irrigation improves intrinsic water-use efficiency and maintains high photosynthesis by uncoupling stomatal and mesophyll conductance in cotton leaves

Partial root-zone drying irrigation (PRD) can improve water-use efficiency (WUE) without reductions in photosynthesis; however, the mechanism by which this is attained is unclear. To amend that, PRD conditions were simulated by polyethylene glycol 6000 in a root-splitting system and the effects of PRD on cotton growth were studied. Results showed that PRD decreased stomatal conductance (gs) but increased mesophyll conductance (gm). Due to the contrasting effects on gs and gm, net photosynthetic rate (AN) remained unaffected, while the enhanced gm/gs ratio facilitated a larger intrinsic WUE. Further analyses indicated that PRD-induced reduction of gs was related to decreased stomatal size and stomatal pore area in adaxial and abaxial surface which was ascribed to lower pore length and width. PRD-induced variation of gm was ascribed to the reduced liquid-phase resistance, due to increases in chloroplast area facing to intercellular airspaces and the ratio of chloroplast surface area to total mesophyll cell area exposed to intercellular airspaces, as well as to decreases in the distance between cell wall and chloroplast, and between adjacent chloroplasts. The above results demonstrate that PRD, through alterations to stomatal and mesophyll structures, decoupled gs and gm responses, which ultimately increased intrinsic WUE and maintained AN.

Effect of Warming on Personality of Mosquitofish (Gambusia affinis) and Medaka Fish (Oryzias latipes)

Global warming may accelerate the process of biological invasions, and invasive species that can quickly adapt to new environments will have a negative impact on native species. Animal personalities have significant implications for ecology and evolution. However, few studies have simultaneously examined the combined effects of climate warming and biological invasions on native species. In this study, we hypothesized that temperature was positively correlated with personality, and invasive species had stronger personalities than native species. Accordingly, we established control (20 °C) and warming groups (20 °C, 25 °C, and 30 °C) to rear mosquitofish and medaka fish, individuals acclimatized to rearing temperatures for 7 days, then measured their personalities (sociability, exploration, novelty, and boldness). The results showed that individuals exhibited repeatable variation along the four behavioral axes across all temperature conditions, providing evidence for the presence of personalities. Significant positive correlations were found between each pair of behaviors, indicating the presence of behavioral syndrome. Sociability and exploration were most affected by temperature, showing increasing trends in sociability, exploration, and novelty in both invasive and native species with rising temperatures. Compared to medaka fish, mosquitofish exhibited higher exploration and lower sociability at elevated temperatures, while showing little change in boldness. Our results provide evidence that increased temperatures may promote biological invasions and pose a potential threat to the survival of native species. These findings are significant for understanding the complex impacts of climate change on ecosystems and for formulating effective biodiversity preservation strategies.

Genetic admixture drives climate adaptation in the bank vole

Genetic admixture introduces new variants at relatively high frequencies, potentially aiding rapid responses to environmental changes. Here, we evaluate its role in adaptive variation related to climatic conditions in bank voles (Clethrionomys glareolus) in Britain, using whole-genome data. Our results reveal loci showing excess ancestry from one of the two postglacial colonist populations inconsistent with overall admixture patterns. Notably, loci associated with climate adaptation exhibit disproportionate amounts of excess ancestry, highlighting the impact of admixture between colonist populations on local adaptation. The results suggest strong and localized selection on climate-adaptive loci, as indicated by steep clines and/or shifted cline centres, during population replacement. A subset, including a haemoglobin gene, is associated with oxidative stress responses, underscoring a role of oxidative stress in local adaptation. Our study highlights the important contribution of admixture during secondary contact between populations from distinct climatic refugia enriching adaptive diversity. Understanding these dynamics is crucial for predicting future adaptive capacity to anthropogenic climate change.

Pollen-mediated gene flow from wild carrots (Daucus carota L. subsp. carota) affects the production of commercial carrot seeds (Daucus carota L. subsp. sativus) internationally and in New Zealand in the context of climate change: A systematic review

Climate change will impact the carrot seed industry globally. One adaptation strategy to limit climatic impacts on the production of commercial carrot seeds is geographical shift. However, production must be shifted to climate-optimal places that are free from weeds such as wild carrots to avoid genetic contamination via hybridization. The process of gene flow between wild and cultivated carrots is critical to enable management of wild carrots in the face of climate change. This review systematically assesses the resilience of wild carrots to climate change and their impact on commercial carrot seed production globally with a focus on New Zealand as a major carrot seed producer. The literature was critically analyzed based on three specific components: i) resilience of wild carrots to climate change ii) genetic contamination between wild and cultivated carrots, and iii) management of wild carrots. The majority of the articles were published between 2013 and 2023 (64.71 %), and most of these studies were conducted in Europe (37.26 %) and North America (27.45 %). Country-wise analysis demonstrated that the majority of the studies were carried out in the United States (23.53 %) and the Netherlands (11.77 %). There was limited research conducted in other regions, especially in Oceania (1.96 %). Spatial distribution analysis revealed that the wild carrot was reported in around 100 countries. In New Zealand the North Island has a higher incidence of wild carrot invasion than the South Island. The findings indicated that the wild carrot is becoming more adaptable to climate change, compromising the genetic purity of cultivated carrots due to pollen flow from wild to cultivated carrots. Therefore, ongoing research will be helpful in developing sustainable weed management strategies and predicting potential geographical invasiveness. This study provides a guide for scientists, policymakers, industrialists, and farmers to control wild carrots and produce genetically pure commercial seeds amid climate change.

Intercropping improves faba bean photosynthesis and reduces disease caused by Fusarium commune and cinnamic acid-induced stress

Modern intensive cropping systems often contribute to the accumulation of phenolic acids in the soil, which promotes the development of soilborne diseases. This can be suppressed by intercropping. This study analyzed the effects of intercropping on Fusarium wilt based on its effect on photosynthesis under stress by the combination of Fusarium commune and cinnamic acid. The control was not inoculated with F. commune, while the faba bean plants (Vicia faba L.) were inoculated with this pathogen in the other treatments. The infected plants were also treated with cinnamic acid. This study examined the development of Fusarium wilt together with its effects on the leaves, absorption of nutrients, chlorophyll fluorescence parameters, contents of photosynthetic pigments, activities of photosynthetic enzymes, gas exchange parameters, and the photosynthetic assimilates of faba bean from monocropping and intercropping systems. Under monocropping conditions, the leaves of the plants inoculated with F. commune grew significantly less, and there was enhanced occurrence of the Fusarium wilt compared with the control. Compared with the plants solely inoculated with F. commune, the exogenous addition of cinnamic acid to the infected plants significantly further reduced the growth of faba bean leaves and increased the occurrence of Fusarium wilt. A comparison of the combination of F. commune and cinnamic acid in intercropped wheat and faba bean compared with monocropping showed that intercropping improved the absorption of nutrients, increased photosynthetic pigments and its contents, electron transport, photosynthetic enzymes, and photosynthetic assimilates. The combination of these factors reduced the occurrence of Fusarium wilt in faba bean and increased the growth of its leaves. These results showed that intercropping improved the photosynthesis, which promoted the growth of faba bean, thus, reducing the development of Fusarium wilt following the stress of infection by F. commune and cinnamic acid. This research should provide more information to enhance sustainable agriculture.

Phytochemical-mediated regulation of aflatoxigenic fungi contamination in a shifting climate and environment

Mycotoxin contamination poses a significant problem in developing countries, particularly in northern Pakistan's fluctuating climate. This study aimed to assess aflatoxin contamination in medicinal and condiment plants in Upper Dir (dry-temperate) and Upper Swat (moist-temperate) districts. Plant samples were collected and screened for mycotoxins (Aflatoxin-B1 and Aflatoxin-B-2). Results showed high levels of AFB-1 (11,505.42 ± 188.82) as compared to AFB-2 (846 ± 241.56). The maximum contamination of AFB-1 in Coriandrum sativum (1154.5 ± 13.43 ng to 3328 ± 9.9 ng) followed by F. vulgare (883 ± 9.89 ng to 2483 ± 8.4 ng), T. ammi (815 ± 11.31 ng to 2316 ± 7.1 ng), and C. longa (935.5 ± 2.12 ng to 2009 ± 4.2 ng) while the minimum was reported in C. cyminum (671 ± 9.91 ng to 1995 ± 5.7 ng). Antifungal tests indicated potential resistance in certain plant species (C. cyminum) while A. flavus as the most toxins contributing species due to high resistance below 80% (54.2 ± 0.55 to 79.5 ± 2.02). HPLC analysis revealed hydroxyl benzoic acid (5136 amu) as the dominant average phytochemical followed by phloroglucinol (4144.31 amu) with individual contribution of 8542.08 amu and 12,181.5 amu from C. cyaminum. The comparison of average phytochemicals revealed the maximum concentration in C. cyminum (2885.95) followed by C. longa (1892.73). The findings revealed a statistically significant and robust negative correlation (y = - 2.7239 ×  + 5141.9; r = - 0.8136; p < 0.05) between average mycotoxins and phytochemical concentrations. Temperature positively correlated with aflatoxin levels (p < 0.01), while humidity had a weaker correlation. Elevation showed a negative correlation (p < 0.05), while geographical factors (latitude and longitude) had mixed correlations (p < 0.05). Specific regions exhibited increasing aflatoxin trends due to climatic and geographic factors.

Genome-wide analysis of LOG family genes in castor and RcLOG5 enhances drought, salt, and cold stress tolerance in Arabidopsis thaliana

The gene encoding the specific phosphohydrolase LONELY GUY (LOG) plays an important role in the activation of cytokinin and the stress response in plant cells. However, the role of LOG genes in castor bean (Ricinus communis) has not been reported. In this study, we identified a total of nine members of the LOG gene family in the castor bean genome and investigated the upregulated expression of the RcLOG5 gene using transcriptome data analysis. We found that the RcLOG5 gene exhibited tissue-specific expression and was activated by polyethylene glycol, NaCl, low temperature, and abscisic acid stress. The subcellular localization results showed that the RcLOG5 gene is mainly located in the cytoplasm. Based on phenotypic and physiological indicators, namely root length, peroxidase activity, and malondialdehyde content, overexpression of the RcLOG5 gene not only improved the drought resistance, salt tolerance, and cold tolerance of transgenic Arabidopsis, but also shortened the dormancy period of the transgenic plants. Transcriptomic sequencing revealed that the overexpression of the RcLOG5 gene led to the enrichment of differentially expressed genes in the glutathione metabolism pathway in transgenic Arabidopsis. Moreover, the overexpression plants had higher levels of glutathione and a higher GSH/GSSG ratio under stress compared to the wild type. Therefore, we inferred that the RcLOG5 gene may be responsible for regulating cell membrane homeostasis by reducing the accumulation of reactive oxygen species through the glutathione pathway. Overall, the overexpression of the RcLOG5 gene positively regulated the stress resistance of transgenic Arabidopsis. This study provides valuable gene resources for breeding stress-tolerant castor bean varieties.

Development, characterization, and evaluation of Zn-SA-chitosan bionanoconjugates on wheat seed, experiencing chilling stress during germination

This study aimed to develop and characterize the chitosan bionanoconjugates (BNCs) loaded with zinc (Zn) and salicylic acid (SA) and test their efficacy on wheat seed exposed to chilling stress. BNCs developed were spherical (480 ± 6.0 nm), porous, and positively charged (+25.2 ± 2.4 mV) with regulated nutrient release properties. They possessed complexation efficiency of 78.4 and 58.9 % for Zn, and SA respectively. BET analysis further confirmed a surface area of 12.04 m2/g. Release kinetics substantiated the release rates of Zn and SA, as 0.579 and 0.559 % per hour, along with a half-life of 119.7 and 124.0 h, respectively. BNCs positively affected the germination potential of wheat seeds under chilling stress as observed by significantly (p < 0.05) reduced mean emergence time (18 %), and increased germination rate (22 %), compared to the control. Higher activities of reserve mobilizing enzymes (α-amylase- 6.5 folds, protease -10.2 folds) as well as faster reserve mobilization of starch (64.4 %) and protein (63.5 %) molecules were also observed. The application further led to increased levels of the antioxidant enzymes (SOD and CAT) and reduced oxidative damage (MDA and H2O2). Thus, it is inferred that the developed BNCs could help substantially improve the germination and reserve mobilization potential, thereby increasing the crop yield.