Impact of Climate Change on Crops Adaptation and Strategies to Tackle Its Outcome: A Review

Analysis of salinity-induced metabolome changes in Indian mustard (Brassica juncea) roots and shoots: hydroponic versus microplot cultivation

BACKGROUND

Brassica juncea L. (family Brassicaceae) or Indian mustard is a fast-growing oilseed crop. Climate changes mean that it is very important to evaluate the effects of salinity stress on B. juncea. The aim of this study was therefore to show the metabolic effect of salinity stress on shoots and roots using two cultivation models - hydroponic and microplot - in different cultivars, including RH-725 and RH-761. Salinity levels of 5, 7.5, and 10 dS m⁻¹ were investigated, and compared with a control of 0 dS m⁻¹, using untargeted metabolomics with gas chromatography-mass spectrometry (GC-MS) post-silylation, focusing on metabolic markers such as proline and glycine-betaine.

RESULTS

A total of 56 metabolites were identified, with the most prevalent classes belonging to sugars (8), followed by organic acids (13), amino acids (11), and fatty acids/esters (11). Shoots were found to have a higher sugar content than roots. Increases in unsaturated fatty acids were also associated with salinity stress, compared with a decrease in saturated fatty acids. Absolute levels of proline and glycine-betaine correlated with salinity stress, with the largest increases detected in shoots grown under hydroponic conditions, particularly for the RH-761 cultivar. Multivariate data analyses revealed that roots were more affected than shoots, regardless of cultivation model.

CONCLUSION

These findings might explain the different metabolic behavior of B. juncea's roots and shoots under various levels of salinity, associated with higher levels of free sugars in shoots and lipids in roots. © 2024 Society of Chemical Industry.

Exogenous melatonin enhances heat tolerance in buckwheat seedlings by modulating physiological response mechanisms

Melatonin (MT) serves as a potent antioxidant in plant organisms, bolstering their resilience to temperature stress. In this study, the impact of MT on various buckwheat varieties under high-temperature stress conditions (40 °C) was investigated. Specifically, five buckwheat seedling varieties, comprising three sweet buckwheat variants (Fagopyrum esculentum) and two bitter buckwheat types (Fagopyrum tataricum), were subjected to foliar sprays of melatonin at concentrations of 50, 100 and 200 μM, with water at 25 °C employed as a control. Results demonstrated that exogenous MT at different concentrations improved the growth and physiological parameters of buckwheats, ameliorating damage induced by high-temperature stress. Notably, the application of 100 μM MT significantly augmented shoot biomasses of buckwheat seedlings under high-temperature conditions. Furthermore, the MT significantly increased the levels of osmotic adjustment substances and chlorophyll concentrations, enhanced antioxidant enzyme activities, chlorophyll fluorescence parameters, and improved photosynthetic gas exchange parameters in five different varieties of buckwheat. This led to the alleviation of damage to buckwheat seedlings subjected to high-temperature stress. Subsequently, five advanced statistical analysis methods: Principal Component Analysis, Grey Relational Analysis, Path Coefficient Analysis, Membership Function Method, and Coupling Coordination Analysis were employed to delve deeper into the existing data indicators. To summarize, the beneficial effect of exogenous melatonin on seedling growth is primarily achieved through the coordination and regulation of the antioxidant enzyme system and osmotic regulatory substances, ensuring the growth and development of buckwheat seedlings while also improving their heat tolerance. The treatment with a concentration of 100 μM of MT was the most effective.

Stress-responsive transcription factor families are key components of the core abiotic stress response in maize

Abiotic stresses, including drought, salt, heat, cold, flooding, and low nitrogen, have devastating impacts on agriculture and are increasing in frequency globally due to climate change. Plants can experience multiple abiotic stresses simultaneously or sequentially within a single growing season, and combinatorial stresses elicit shared or overlapping molecular and physiological responses. Here, we searched for core stress responsive genes in maize across diverse abiotic stressors through meta-analysis of public RNAseq data. Our analysis revealed significant heterogeneity in gene expression across datasets due to factors such as tissue type, genotype, and experimental conditions, which we mitigated through batch correction. Using nearly 1,900 RNAseq samples with both traditional set operations and a novel random forest machine learning approach, we identified a core set of 744 stress-responsive genes across the six stresses. These core genes are enriched in transcription factors, including stress-responsive families such as AP2/ERF-ERF, NAC, bZIP, HSF, and C2C2-CO-like. Co-expression network analysis demonstrated that these core TFs are co-expressed with stress-specific peripheral genes, supporting their role in regulating both generalized and stress-specific responses. Our results suggest that maize employs a conserved yet flexible transcriptional strategy to respond to abiotic stresses, with core TFs acting as potential regulators of both universal and stress-specific pathways. These findings provide a valuable resource for understanding stress tolerance mechanisms and for guiding future breeding and engineering efforts to enhance maize resilience under climate change.

Mitigating low-temperature stress in alfalfa by postponing phosphorus application and remodeling of antioxidant activities and carbon-nitrogen metabolism

Low-temperature stress has become a major limiting factor for the sustainable production of forage crops and animal husbandry. This experimental study evaluated the effects of optimizing phosphorus application on the antioxidant properties and carbon-nitrogen metabolism physiology of alfalfa (Medicago sativa L.) under LT stress, aiming to provide a reference for efficient stress-resistant alfalfa production. In this study, the LT tolerant cultivar 'Caoyuan' (CY) and LT sensitive cultivar 'Xinmu' (XM) were used as plant materials, and the physiological changes of alfalfa plants under natural temperature (NT) and LT were compared under traditional phosphorus application (R1) and postponing phosphorus application (R2) treatments. The results showed that LT stress increased the accumulation of malondialdehyde (MDA) in alfalfa plants and inhibited root activity, carbon metabolism, and photosynthesis in both cultivars. The negative impacts of LT are more prevalent in XM than in CY. The postponing phosphorus application treatments enhanced root vitality as compared to the traditional phosphorus application treatments and accumulated more soluble sugar (5.6-11.2%), sucrose (8.5-14.0%), proline (7.5-11.7%), and soluble protein (8.3-11.7%) by increasing the enzyme activities related to carbon-nitrogen metabolism. Under postponing phosphorus application treatments, the enzymatic activities of antioxidants and regulation of osmotic sub-stances significantly increased in the leaves, MDA contents were decreased by 4.6-7.6%, and chlorophyll contents were increased by 4.8-8.6%, the net photosynthetic rate in alfalfa leaves increased by 5.1-7.5%. Besides, plant dry weight, root dry weight, and plant phosphorus concentration increased by 5.8-16.9%, 7.8-21.0%, and 5.1-9.9% under postponing phosphorus application treatments. In summary, split-phosphorus fertilization improved the nutrient absorption capacity of alfalfa roots compared to traditional phosphorus application treatments under LT stress. Moreover, it improved the carbon-nitrogen metabolism physiology and photosynthetic production capacity of the alfalfa plants, thus reducing the adverse effects of LT stress on the growth and development of alfalfa.

Advanced technologies for reducing greenhouse gas emissions from rice fields: Is hybrid rice the game changer?

Rice is a staple food for half of the world's population and the largest source of greenhouse gas (GHG) from the agricultural sector, responsible for approximately 48% of GHG emissions from croplands. With the rapid growth of the human population, the increasing pressure on rice systems for extensive and intensive farming is associated with an increase in GHG emissions that is impeding global efforts to mitigate climate change. The complex rice environment, with its genotypic variability among rice cultivars, as well as emerging farming practices and global climatic changes, are important challenges for research and development initiatives that aim to lower GHG emissions and increase crop productivity. A combination of approaches will likely be needed to effectively improve the resilience of modern rice farming. These will include a better understanding of the major drivers of emissions, different cropping practices to control the magnitude of emissions, and high yield performance through systems-level studies. The use of rice hybrids may give farmers an additive advantage, as hybrids may be better able to resist environmental stress than inbred varieties. Recent progress in the development and dissemination of hybrid rice has demonstrated a shift in the carbon footprint of rice production and is likely to lead the way in transforming rice systems to reduce GHG emissions. The application of innovative technologies such as high-throughput sequencing, gene editing, and AI can accelerate our understanding of the underlying mechanisms and critical drivers of GHG emissions from rice fields. We highlight advanced practical approaches to rice breeding and production that can support the increasing contribution of hybrid rice to global food and nutritional security while ensuring a sustainable and healthy planet.

Insights into the Role of GhTAT2 Genes in Tyrosine Metabolism and Drought Stress Tolerance in Cotton

Gossypium hirsutum is a key fiber crop that is sensitive to environmental factors, particularly drought stress, which can reduce boll size, increase flower shedding, and impair photosynthesis. The aminotransferase (AT) gene is essential for abiotic stress tolerance. A total of 3 Gossypium species were analyzed via genome-wide analysis, and the results unveiled 103 genes in G. hirsutum, 47 in G. arboreum, and 53 in G. raimondii. Phylogenetic analysis, gene structure examination, motif analysis, subcellular localization prediction, and promoter analysis revealed that the GhAT genes can be classified into five main categories and play key roles in abiotic stress tolerance. Using RNA-seq expression and KEGG enrichment analysis of GhTAT2, a coexpression network was established, followed by RT-qPCR analysis to identify hub genes. The RT-qPCR results revealed that the genes Gh_A13G1261, Gh_D13G1562, Gh_D10G1155, Gh_A10G1320, and Gh_D06G1003 were significantly upregulated in the leaf and root samples following drought stress treatment, with Gh_A13G1261 identified as the hub gene. The GhTAT2 genes were considerably enriched for tyrosine, cysteine, methionine, and phenylalanine metabolism and isoquinoline alkaloid, tyrosine, tryptophan, tropane, piperidine, and pyridine alkaloid biosynthesis. Under drought stress, KEGG enrichment analysis manifested significant upregulation of amino acids such as L-DOPA, L-alanine, L-serine, L-homoserine, L-methionine, and L-cysteine, whereas metabolites such as maleic acid, p-coumaric acid, quinic acid, vanillin, and hyoscyamine were significantly downregulated. Silencing the GhTAT2 gene significantly affected the shoot and root fresh weights of the plants compared with those of the wild-type plants under drought conditions. RT-qPCR analysis revealed that GhTAT2 expression in VIGS-treated seedlings was lower than that in both wild-type and positive control plants, indicating that silencing GhTAT2 increases sensitivity to drought stress. In summary, this thorough analysis of the gene family lays the groundwork for a detailed study of the GhTAT2 gene members, with a specific focus on their roles and contributions to drought stress tolerance.

Insights into quinoa endophytes: core bacterial communities reveal high stability to water stress and genotypic variation

BACKGROUND

Plant endophytes, comprising non-pathogenic bacteria, fungi, and archaea, inhabit various plant parts, including roots, stems, leaves, and seeds. These microorganisms play a crucial role in plant development by enhancing germination, growth, and stress resilience. Seed endophytes, in particular, represent the most adapted and conserved segment of plant microbiota, significantly influencing the initial stages of plant growth and microbial community establishment. This study investigates the impact of environmental and genotypic factors on the endophytic communities of Chenopodium quinoa Willd. (quinoa), a crop notable for its adaptability and nutritional value.

RESULTS

We aimed to characterize the core endophytic communities in quinoa seeds and roots from two distinct genotypes under well-watered (WW) and water-deficit (WD) conditions, utilizing various soil infusions as inoculants to explore potential changes in these endophytes. Our findings reveal distinct changes with quinoa seeds exhibiting a high degree of conservation in their endophytic microbiome, even between maternal and offspring seeds, with specific bacterial taxa showing only minor differences. Tissue specificity emerged as a key factor, with seeds maintaining a stable microbial community, while roots exhibited more pronounced shifts, highlighting the tissue-dependent patterns of microbial enrichment.

CONCLUSIONS

The results highlight the stability and conservation of endophytic communities in quinoa seeds, even under varying water conditions and across different genotypes, emphasizing the role of tissue specificity in shaping microbial associations. These findings suggest that quinoa-associated endophytes, particularly those conserved in seeds, may play a crucial role in enhancing drought resilience. Understanding the dynamics of plant-microbe interactions in quinoa is vital for developing stress-resilient crop varieties, supporting sustainable agricultural practices, and ensuring food security in the face of climate change and environmental challenges.

Advancing vegetable genetics with gene editing: a pathway to food security and nutritional resilience in climate-shifted environments

As global populations grow and climate change increasingly disrupts agricultural systems, ensuring food security and nutritional resilience has become a critical challenge. In addition to grains and legumes, vegetables are very important for both human and animals because they contain vitamins, minerals, and fibre. Enhancing the ability of vegetables to withstand climate change threats is essential; however, traditional breeding methods face challenges due to the complexity of the genomic clonal multiplication process. In the postgenomic era, gene editing (GE) has emerged as a powerful tool for improving vegetables. GE can help to increase traits such as abiotic stress tolerance, herbicide tolerance, and disease resistance; improve agricultural productivity; and improve nutritional content and shelf-life by fine-tuning key genes. GE technologies such as Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9 (CRISPR-Cas9) have revolutionized vegetable breeding by enabling specific gene modifications in the genome. This review highlights recent advances in CRISPR-mediated editing across various vegetable species, highlighting successful modifications that increase their resilience to climatic stressors. Additionally, it explores the potential of GE to address malnutrition by increasing the nutrient content of vegetable crops, thereby contributing to public health and food system sustainability. Additionally, it addresses the implementation of GE-guided breeding strategies in agriculture, considering regulatory, ethical, and public acceptance issues. Enhancing vegetable genetics via GE may provide a reliable and nutritious food supply for an expanding global population under more unpredictable environmental circumstances.

Patterns and Drivers of Pollen Temperature Tolerance

Pollen, a pivotal stage in the plant reproductive cycle, is highly sensitive to temperature fluctuations, impacting seed quality and quantity. While the importance of understanding pollen temperature limits (Tmin, Topt, Tmax - collectively PTLs) is recognized, a comprehensive synthesis of underlying drivers is lacking. Here, we examined PTLs, correlating them with vegetative tissue thermotolerance and assessing variability at the intra- and interspecific levels across 191 species with contrasting phylogeny, cultivation history, growth form and ecology. At the species level, the PTLs range from 9.0 to 42.4°C, with considerable differences among individual species. Vegetative tissue showed greater tolerance to both low and high temperatures than pollen. A significant, though weak, correlation was observed between PTLs and leaf temperature tolerance. Pollen heat tolerance was independent of that in leaves and stems. The greatest intraspecific variability was observed in pollen cold tolerance (Tmin), followed by Topt and Tmax. Phylogenetic analysis revealed family-level conservation in all three pollen temperature tolerance measures. Climate emerged as a significant PTL driver of pollen cold tolerance, with species from colder and stable climates exhibiting enhanced cold tolerance. Cultivated and wild species did not differ in their pollen temperature tolerances. Herbaceous plants showed higher tolerance to high temperatures compared to shrubs and trees, potentially reflecting divergent thermal conditions during anthesis. This study provides the first formal analysis of complex relationships between pollen temperature limits, plant characteristics and environmental factors, providing crucial insights into climate change impacts on plant reproduction.

Haplotype breeding: fast-track the crop improvements

MAIN CONCLUSION

Haplotype-based breeding unleashed the genetic variations of unexplored germplasms and integration with recent genomics tools accelerated the genetic gain and address the present challenges of food security by climate change. Climate change is linked to unforeseen abiotic stresses and changes in the patterns of pests and diseases. Hence, it is necessary to use novel methods to detect genetic variations to mitigate the adverse effects on crops by climate change. Genomic-assisted breeding methods are strategies that improve the efficiency of breeding cereal crops in a dynamic environment. These methods detect differences in the structure of single nucleotide polymorphisms (SNPs) throughout the population. The decrease in sequencing costs has enabled the thorough sequencing of crop genomes, resulting in the discovery of millions of SNPs. By using statistical tests, it is possible to integrate these SNPs into a limited number of haplotype blocks. This allows for a more comprehensive analysis of how variation is distributed and segregated within a population. Therefore, the use of haplotype-based breeding shows great potential as a tool for creating tailored crop varieties. The process entails the identification of superior haplotypes and their use in breeding operations. The haplotype-based breeding (HBB) technique utilizes genome sequence data to identify specific allelic variations that accelerate the breeding cycle and overcome linkage drag difficulties. This study aims to present the idea of HBB, examine the connection between haplotype breeding and conventional breeding, and analyze the benefits and current advancements of HBB, with a specific focus on cereal crops.

Unravelling the secrets of soil microbiome and climate change for sustainable agroecosystems

The soil microbiota exhibits an important function in the ecosystem, and its response to climate change is of paramount importance for sustainable agroecosystems. The macronutrients, micronutrients, and additional constituents vital for the growth of plants are cycled biogeochemically under the regulation of the soil microbiome. Identifying and forecasting the effect of climate change on soil microbiomes and ecosystem services is the need of the hour to address one of the biggest global challenges of the present time. The impact of climate change on the structure and function of the soil microbiota is a major concern, explained by one or more sustainability factors around resilience, reluctance, and rework. However, the past research has revealed that microbial interventions have the potential to regenerate soils and improve crop resilience to climate change factors. The methods used therein include using soil microbes' innate capacity for carbon sequestration, rhizomediation, bio-fertilization, enzyme-mediated breakdown, phyto-stimulation, biocontrol of plant pathogens, antibiosis, inducing the antioxidative defense pathways, induced systemic resistance response (ISR), and releasing volatile organic compounds (VOCs) in the host plant. Microbial phytohormones have a major role in altering root shape in response to exposure to drought, salt, severe temperatures, and heavy metal toxicity and also have an impact on the metabolism of endogenous growth regulators in plant tissue. However, shelf life due to the short lifespan and storage time of microbial formulations is still a major challenge, and efforts should be made to evaluate their effectiveness in crop growth based on climate change. This review focuses on the influence of climate change on soil physico-chemical status, climate change adaptation by the soil microbiome, and its future implications.

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.

Combined effects of climate stressors and soil arsenic contamination on metabolic profiles and productivity of rice (Oryza sativa L.)

Rice productivity and quality are increasingly at risk in arsenic (As) affected areas, challenge that is expected to worsen under changing climatic conditions. Free-Air Concentration Enrichment experiments revealed that eCO2, eO3, and eTemp, whether acting individually or in combination with low and high As irrigation, significantly impact rice yield and grain quality. Elevated CO₂ significantly increased shoot biomass, with minimal impact on root biomass, except under low As irrigation conditions. In contrast, eTemp alone reduced both shoot and root biomass, though the effect was not significant; eO₃ alone had little to no effect. Combined climatic stressors showed slight positive effects on growth. Under low As irrigation, eCO2 and eO3 promoted root growth but reduced shoot growth, while eTemp significantly suppressed both. High As irrigation exacerbated yield reductions, with the most severe decline observed under eTemp (66 %), followed by eCO2 (48 %), eO3 (36 %), and their combination (35 %). Arsenic irrigation, whether low or high, reduced macro and micronutrient concentrations in rice grains, with calcium being sole exception, remaining stable or even increasing. Sugar metabolites decreased under eCO2, eO3, and eTemp, but increased with As irrigation. Interestingly, climatic variables generally reduced grain As levels, high As irrigation combined with eCO2 exposure resulted in elevated grain As. This poses a dual concern: increased cancer risk due to As but potential benefit for individuals with diabetes, as the higher amylose content contributes to lower glycemic index. However, rice grown under high As irrigation exhibited significant nutritional imbalances, being rich in maltose and amylose but deficient in organic acids, phytosterols, fatty acids, organosilicons, and carboxylic acids. These findings underscore the dual threat of climate change and As contamination to rice productivity and quality. Developing resilient rice varieties with low grain As content is essential to ensure sustainable agricultural production and nutritional security in As affected regions.

Combining genotyping approaches improves resolution for association mapping: a case study in tropical maize under water stress conditions

Genome-wide Association Studies (GWAS) identify genome variations related to specific phenotypes using Single Nucleotide Polymorphism (SNP) markers. Genotyping platforms like SNP-Array or sequencing-based techniques (GBS) can genotype samples with many SNPs. These approaches may bias tropical maize analyses due to reliance on the temperate line B73 as the reference genome. An alternative is a simulated genome called "Mock," adapted to the population using bioinformatics. Recent studies show SNP-Array, GBS, and Mock yield similar results for population structure, heterotic groups definition, tester selection, and genomic hybrid prediction. However, no studies have examined the results generated by these different genotyping approaches for GWAS. This study aims to test the equivalence among the three genotyping scenarios in identifying significant effect genes in GWAS. To achieve this, maize was used as the model species, where SNP-Array genotyped 360 inbred lines from a public panel via the Affymetrix platform and GBS. The GBS data were used to perform SNP calling using the temperate inbred line B73 as the reference genome (GBS-B73) and a simulated genome "Mock" obtained in-silico (GBS-Mock). The study encompassed four above-ground traits with plants grown under two levels of water supply: well-watered (WW) and water-stressed (WS). In total, 46, 34, and 31 SNP were identified in the SNP-Array, GBS-B73, and GBS-Mock scenarios, respectively, across the two water levels, associated with the evaluated traits following the comparative analysis of each genotyping method individually. Overall, the identified candidate genes varied along the various scenarios but had the same functionality. Regarding SNP-Array and GBS-B73, genes with functional similarity were identified even without coincidence in the physical position of the SNPs. These genes and regions are involved in various processes and responses with applications in plant breeding. In terms of accuracy, the combination of genotyping scenarios compared to those isolated is feasible and recommended, as it increased all traits under both water conditions. In this sense, it is worth highlighting the combination of GBS-B73 and GBS-Mock scenarios, not only due to the increase in the resolution of GWAS results but also the reduction of costs associated with genotyping and the possibility of conducting genomic breeding methods.

Mitigation of High Temperatures with Ascophyllum nodosum Biostimulants in Papaya (Carica papaya L.) Seedlings

High temperatures can interfere with plant metabolism and physiology, compromising productivity. One tactic to minimize the effects of heatwaves on agriculture is the use of bio-stimulants. This study evaluated two commercial products (Baltiko® and Acadian®) containing Ascophyllum nodosum in 'Aliança' papaya (Carica papaya L.) seedlings. Six doses (0, 1, 2, 3, 4, and 8 mL L-1) were applied weekly for four weeks at two distinct times, considering moderate and high temperatures. The results indicated distinct effects on gas exchange, seedling development, and nutrient content in leaves and roots. During the moderate temperature period, increasing doses enhanced gas exchange and aerial development, along with increases in potassium and boron levels in the leaves, while root growth decreased. Acadian® provided higher levels of boron in leaves and roots compared to Baltiko®. During the period of elevated temperature, increases were observed in leaf area, root dry mass, and leaf content of phosphorus, potassium, sulfur, and zinc, along with potassium in the roots. These increases were primarily attributed to the effects of the applied biostimulants. A lower dose (3 mL L-1) is recommended during mild temperatures, while a higher dose (6 mL L-1) is suggested for elevated temperatures.

The members of zinc finger-homeodomain (ZF-HD) transcription factors are associated with abiotic stresses in soybean: insights from genomics and expression analysis

BACKGROUND

Zinc finger homeodomain (ZF-HD) belongs to the plant-specific transcription factor (TF) family and is widely involved in plant growth, development and stress responses. Despite their importance, a comprehensive identification and analysis of ZF-HD genes in the soybean (Glycine max) genome and their possible roles under abiotic stress remain unexplored.

RESULTS

In this study, 51 ZF-HD genes were identified in the soybean genome that were unevenly distributed on 17 chromosomes. All GmZF-HD genes contained a conserved ZF-HD_dimer domain and had diverse physicochemical features. Furthermore, the GmZF-HD gene structures exhibited 3 to 10 conserved motifs, and most of them showed intronless gene structures. Phylogenetic analysis categorized them into eight major groups with the highest closeness to dicots including Brassica rapa and Malus domestica. The cis-element analysis recognized plant growth and development (10%), phytohormones (31%) and stress-responsive (59%) elements. Synteny analysis identified 73 segmental and 1 tandem duplicated genes that underwent purifying selection. The collinearity analysis revealed that GmZF-HD genes showed higher homology with dicot species, indicating common ancestors with close evolutionary relationships. A total of 94 gma-miRNAs from 41 diverse miRNA families were identified, targeting 40 GmZF-HD genes, with GmZF-HD6 being most targeted by 7 miRNAs, and gma-miR4993 emerging as the dominant miRNA family. Different TFs including ERF, LBD, BBR-BPC and MYB, etc., were predicted in all 51 GmZF-HD genes upstream regions and visualized in the network. Expression profiling through RNA-Seq showed diverse expressions of GmZF-HD genes in different tissues including seeds, roots, shoots and leaves under diverse conditions. Further, the qRT-PCR analysis demonstrated that all tested GmZF-HD genes were significantly induced in soybean leaves, mainly the GmZF-HD5/6/13/39 and GmZF-HD45 genes were significantly upregulated (2.5 to 8.8 folds) under the tested stress treatments compared to control, highlighting their potential roles in response to stresses in soybean.

CONCLUSION

Overall, this study reveals comprehensive insights into the ZF-HD genes in soybeans and provides a valuable contribution towards functional studies for soybean improvement under stress conditions.

Effect of crude extract and polysaccharides derived from Fucus spiralis on radish plants Raphanus sativus L. agrophysiological traits under drought stress

Drought is a significant environmental stressor that induces changes in the physiological, morphological, biochemical, and molecular traits of plants, ultimately resulting in reduced plant growth and crop productivity. Seaweed extracts are thought to be effective in mitigating the effects of drought stress on plants. In this study, we investigated the impact of crude extract (CE), and polysaccharides (PS) derived from the brown macroalgae Fucus spiralis (Heterokontophyta, Phaeophyceae) applied at 5% (v/v) and 0.1% (w/v) respectively on radish plants Raphanus sativus L. subjected to varying levels of drought stress, specifically 80% of field capacity (FC) for no stress, 60% FC for moderate stress, and 40% FC for severe stress. Our examination of growth parameters, along with physiological and biochemical characteristics, revealed that both CE and PS increased the fresh weight over the control by 47.43% and 64% at 40% FC and 12.5% and 38% at 60% FC respectively. Under stress (40% FC), the application of CE and PS decreased proline content of radish leaves by 23.45% and 6.46% respectively in comparison with the control. Furthermore, PS treatment caused an increase of the alkaline phosphatase and urease activity in the soil by 182.5% and 34.6% respectively. CE and PS treatments led to decreased sugar content and total phenolics levels. Notably, lipid peroxidation was reduced in stressed plants treated with both CE and PS, with PS treatment yielding lower concentrations (3.75 nmol MDA.g- 1 FW at 40% FC). Overall, F. spiralis extracts interacted through several mechanisms using various compounds to mitigate the negative effects of drought stress on radish plants. These results demonstrate that seaweed extracts could be adopted in integrated production systems to boost food productivity under harsh climatic conditions.

Halotolerant bacterial endophyte Bacillus velezensis CBE mediates abiotic stress tolerance with minimal transcriptional modifications in Brachypodium distachyon

Nitrogen and water are the primary resources limiting agricultural production worldwide. We have demonstrated the ability of a novel halotolerant bacterial endophyte, Bacillus velezensis CBE, to induce osmotic stress tolerance in Brachypodium distachyon under nitrogen-deprived conditions. Additionally, we aimed to identify the molecular factors in plants that contribute to the beneficial effects induced by B. velezensis CBE in B. distachyon. To achieve this, we conducted transcriptomic profiling using RNA-seq on 18-day-old B. distachyon seedlings treated with B. velezensis CBE in the presence or absence of available nitrogen, with and without osmotic stress. These profiles were then compared to those obtained from B. distachyon treated with known plant growth-promoting bacterial strains, Azospirillum brasilense Cd and Azoarcus olearius DQS4, under the same growth conditions. We identified differentially expressed genes (DEGs) in response to the combinations of bacterial strains and stress treatments. Interestingly, only 73 transcripts showed significant differential expression in B. velezensis CBE-treated plants under stress conditions, compared to 1,078 DEGs in plants treated with A. brasilense Cd and 2,015 DEGs in A. olearius DQS4. Our findings suggest that the novel endophyte B. velezensis CBE mediates osmotic stress tolerance in B. distachyon through the fine-tuning of molecular mechanisms with minimal transcriptional modifications.

Odyssey of environmental and microbial interventions in maize crop improvement

Maize (Zea mays) is India's third-largest grain crop, serving as a primary food source for at least 30% of the population and sustaining 900 million impoverished people globally. The growing human population has led to an increasing demand for maize grains. However, maize cultivation faces significant challenges due to a variety of environmental factors, including both biotic and abiotic stresses. Abiotic stresses such as salinity, extreme temperatures, and drought, along with biotic factors like bacterial, fungal, and viral infections, have drastically reduced maize production and grain quality worldwide. The interaction between these stresses is complex; for instance, abiotic stress can heighten a plant's susceptibility to pathogens, while an overabundance of pests can exacerbate the plant's response to environmental stress. Given the complexity of these interactions, comprehensive studies are crucial for understanding how the simultaneous presence of biotic and abiotic stresses affects crop productivity. Despite the importance of this issue, there is a lack of comprehensive data on how these stress combinations impact maize in key agricultural regions. This review focuses on developing abiotic stress-tolerant maize varieties, which will be essential for maintaining crop yields in the future. One promising approach involves the use of Plant Growth-Promoting Rhizobacteria (PGPR), soil bacteria that colonize the rhizosphere and interact with plant tissues. Scientists are increasingly exploring microbial strategies to enhance maize's resistance to both biotic and abiotic stresses. Throughout the cultivation process, insect pests and microorganisms pose significant threats to maize, diminishing both the quantity and quality of the grain. Among the various factors causing maize degradation, insects are the most prevalent, followed by fungal infections. The review also delves into the latest advancements in applying beneficial rhizobacteria across different agroecosystems, highlighting current trends and offering insights into future developments under both normal and stress conditions.

Stress-relieving plant growth-promoting bacterial co-inoculation enhances nodulation and nitrogen uptake in black gram under nitrogen-free saline conditions

Non-halophytic plants are highly susceptible to salt stress, but numerous studies have shown that halo-tolerant microorganisms can alleviate this stress by producing phytohormones and enhancing nutrient availability. This study aimed to identify and evaluate native microbial communities from salt-affected regions to boost black gram (Vigna mungo) resilience against salinity, while improving plant growth, nitrogen uptake, and nodulation in saline environments. Six soil samples were collected from a salt-affected region in eastern Uttar Pradesh, revealing high electrical conductivity (EC) and pH, along with low nutrient availability. A total of 72 bacterial strains were isolated from soil and 28 from black gram (Vigna mungo) root nodules, with 32 of the soil bacteria tolerating up to 10% NaCl. These bacteria were characterized through taxonomic and biochemical tests. Cross-compatibility analysis showed two rhizobia strains were highly compatible with five salt-tolerant bacteria. These strains exhibited significant plant growth-promoting traits, including phosphate, potassium, and zinc solubilization, as well as ACC deaminase, IAA, siderophore, and EPS production. Strain Paenibacillus sp. SPR11 showed the strongest overall performance. Genetic diversity was assessed using BOX-PCR and ERIC-PCR, and strains were identified through 16S rRNA gene sequencing. In a seed germination study under saline conditions (200 mM and 300 mM), co-inoculation with Bradyrhizobium yuanmingense PR3 and Paenibacillus sp. SPR11 resulted in a significant enhancement in seed germination (40%), root growth (84.45%), and shoot growth (90.15%) compared to single inoculation of B. yuanmingense PR3. Under greenhouse conditions in Leonard jars, co-inoculation with strains PR3 and SPR11 significantly enhanced shoot and root length, fresh and dry biomass, nodule count, and nodule fresh and dry weight. Chlorophyll content, nutrient uptake, and crude protein levels increased, while proline content decreased compared to single inoculation and uninoculated seeds. Our best understanding leads us to believe that this is the very first report of utilizing co-inoculation of salt-tolerant Paenibacillus sp. SPR11 and B. yuanmingense PR3, demonstrating their promising potential to alleviate salt stress and enhance growth, root architecture, nitrogen uptake, and nodule formation in black gram under nitrogen free saline conditions.

Cover crops as climate insurance: Exploring the role of crop insurance discounts to promote climate adaptation and mitigate risk

Climate adaptation is vital for agriculture to manage the growing risks from more frequent droughts, floods, and extreme heat. Yet, adaptation measures remain underused in some of the most agriculturally productive regions, such as the U.S. Cornbelt. Cover crops represent a growing but still underutilized adaptation measure that offers co-benefits to farmers and society. In this study we examine farmers' perceptions of cover crops as a climate adaptation tool and explore the potential for integrating cover crops into existing crop insurance. We surveyed 1023 farmers in Illinois, Indiana, and Iowa to examine what factors shape cover crop acreage, intensity (percent of farm with cover crops), and farmers' future cover crop plans through negative binomial and ordered logit regression models. In addition, we explored farmers' views on policy changes to incorporate the use of cover crops into crop insurance decisions. We found that farmers largely do not perceive extreme weather as a factor in their cover crop decisions, but they do see cover crops as effective in mitigating some impacts of extreme weather. Nearly twice as many farmers reported neutral or improving cash crop yields following cover crops as those who reported declining cash crop yields. Perceptions of negative cash crop yield responses correlated to fewer acres, lower intensities, and plans for fewer cover crops, while positive yield responses only predicted plans to increase cover crops. Program enrollment, self-efficacy, and reduced tillage were all associated with higher cover crop intensities, acres, and plans. Farm size was positively correlated with more acres of cover crops but also lower intensities. Farmers were interested in crop insurance discounts and carbon markets as policy instruments but ranked cost-share programs as their top option overall. Future research should further explore the link between training, experience, and financial costs to inform what policy instruments will most effectively support scaling up cover crop adoption.

Trends of Nanobiosensors in Modern Agriculture Systems

Sustainable agriculture and the provision of food for all become dependent on the availability of efficient diagnostic techniques for the prompt identification of plant diseases. Current scientific findings suggest that nanotechnology can positively affect the agrifood industry by reducing the adverse effects of agricultural practices on human health and the environment, increasing food security and productivity, and fostering social and economic justice. Nanomaterials' unique physical and chemical characteristics have made it possible to employ them as cutting-edge, effective diagnostic instruments for various plant infections and other significant disease biomarkers. By creating diagnostic instruments and methods, nanobiosensors significantly contribute to the revolution of farming. In real time, nanobiosensors can detect infections, metabolites, pesticides, nutrient levels, soil moisture, and temperature. This helps with precision farming techniques and maximises resource use. To better address agricultural concerns, we have included the most recent research on the concept, types, applications, commercial aspects, and future scope of nanobiosensors in this review.

Exploring and exploiting the rice phytobiome to tackle climate change challenges

The future of agriculture is uncertain under the current climate change scenario. Climate change directly and indirectly affects the biotic and abiotic elements that control agroecosystems, jeopardizing the safety of the world's food supply. A new area that focuses on characterizing the phytobiome is emerging. The phytobiome comprises plants and their immediate surroundings, involving numerous interdependent microscopic and macroscopic organisms that affect the health and productivity of plants. Phytobiome studies primarily focus on the microbial communities associated with plants, which are referred to as the plant microbiome. The development of high-throughput sequencing technologies over the past 10 years has dramatically advanced our understanding of the structure, functionality, and dynamics of the phytobiome; however, comprehensive methods for using this knowledge are lacking, particularly for major crops such as rice. Considering the impact of rice production on world food security, gaining fresh perspectives on the interdependent and interrelated components of the rice phytobiome could enhance rice production and crop health, sustain rice ecosystem function, and combat the effects of climate change. Our review re-conceptualizes the complex dynamics of the microscopic and macroscopic components in the rice phytobiome as influenced by human interventions and changing environmental conditions driven by climate change. We also discuss interdisciplinary and systematic approaches to decipher and reprogram the sophisticated interactions in the rice phytobiome using novel strategies and cutting-edge technology. Merging the gigantic datasets and complex information on the rice phytobiome and their application in the context of regenerative agriculture could lead to sustainable rice farming practices that are resilient to the impacts of climate change.

Light-chilling Stress Causes Hyper-accumulation of Iron in Shoot, Exacerbating Leaf Oxidative Damage in Cucumber

Iron availability within the root system of plants fluctuates depending on various soil factors, which directly impacts plant growth. Simultaneously, various environmental stressors, such as high/low temperatures and high light intensity, affect plant photosynthesis in the leaves. However, the combined effects of iron nutrient conditions and abiotic stresses have not yet been clarified. In this study, we analyzed how iron nutrition conditions impact the chilling-induced damage on cucumber leaves (Cucumis sativus L.). When cucumbers were grown under different iron conditions and then exposed to chilling stress, plants grown under a high iron condition exhibited more severe chilling-induced damage than the control plants. Conversely, plants grown under a low-iron condition showed an alleviation of the chilling-induced damages. These differences were observed in a light-dependent manner, indicating that iron intensified the toxicity of reactive oxygen species generated by photosynthetic electron transport. In fact, plants grown under the low-iron condition showed less accumulation of malondialdehyde derived from lipid peroxidation after chilling stress. Notably, the plants grown under the high iron condition displayed a significant accumulation of iron and an increase in lipid peroxidation in the shoot, specifically after light-chilling stress, but not after dark-chilling stress. This indicated that increased root-to-shoot iron translocation, driven by light and low temperature, exacerbated leaf oxidative damage during chilling stress. These findings also highlight the importance of managing iron nutrition in the face of chilling stress and will facilitate crop breeding and cultivation strategies.

Soil Sensor Use in Delimiting Management Zones for Sowing Maize in No-Till

This study aimed to analyze yield components and maize yield cultivated at different population densities in management zones (MZs) delimited based on mapping the spatial variability of the soil's apparent electrical conductivity (ECa). The soil ECa was measured, and two MZs were subsequently delimited, one with low ECa and the other with high ECa. In each MZ, four maize sowing densities were tested: 60,000 (D1); 80,000 (D2); 100,000 (D3); and 140,000 (D4) seeds ha-1. Ear length, number of grains per ear, number of grains per row, number of rows per ear, thousand-grain weight, and yield were evaluated. The increase in sowing density in the high ECa MZ linearly reduced the values of ear diameter, number of rows per ear, number of grains per ear, and thousand-grain weight. Sowing density D3, when implemented in the low ECa MZ, showed higher values for the ear length, ear diameter, number of grains per row, number of grains per ear, and thousand-grain weight. Sowing density D2 was the one with the highest yield, regardless of the MZ where it was implemented (5628.48 kg ha-1 in the high ECa management zone and 4463.63 kg ha-1 in the low ECa).

A Critical Review of Recent Advances in Maize Stress Molecular Biology

With the intensification of global climate change and environmental stress, research on abiotic and biotic stress resistance in maize is particularly important. High temperatures and drought, low temperatures, heavy metals, salinization, and diseases are widespread stress factors that can reduce maize yields and are a focus of maize-breeding research. Molecular biology provides new opportunities for the study of maize and other plants. This article reviews the physiological and biochemical responses of maize to high temperatures and drought, low temperatures, heavy metals, salinization, and diseases, as well as the molecular mechanisms associated with them. Special attention is given to key transcription factors in signal transduction pathways and their roles in regulating maize stress adaptability. In addition, the application of transcriptomics, genome-wide association studies (GWAS), and QTL technology provides new strategies for the identification of molecular markers and genes for maize-stress-resistance traits. Crop genetic improvements through gene editing technologies such as the CRISPR/Cas system provide a new avenue for the development of new stress-resistant varieties. These studies not only help to understand the molecular basis of maize stress responses but also provide important scientific evidence for improving crop tolerance through molecular biological methods.

Integrating genetic assortment and molecular insights for climate-resilient breeding to unravel drought tolerance in cotton

This study addresses the challenges posed by rainfall variability, leading to water deficits during critical stages of crop growth, resulting in a drastic reduction of cotton yield. In a comprehensive evaluation, thirty cotton genotypes, including five Gossypium arboreum (wild) and twenty-five Gossypium hirsutum (cultivated), were grown under rainfed and irrigated conditions. Drought tolerance indices (DTI) were evaluated, categorizing genotypes based on their resilience. Further, in-vitro screening at the seedling stage (20 days) under PEG-induced drought identified tolerant genotypes exhibiting elevated levels of free proline (19.07±5.31 mg.g-100fr.wt.), amino acids (34.59±6.51 mg.g-100fr.wt.), soluble proteins (13.73±2.65 mg.g-1fr.wt.), and glycine betaine (10.95±3.62 mg.g-100fr.wt.), in their leaves, positively correlating (p<0.001) with relative water content (87.70±3.45 %). Molecular analysis using drought-specific simple sequence repeats (SSR) markers revealed significant genetic variability in a cotton genotypes, with lower observed and higher expected heterozygosity. F statistics exposed a higher level of gene flow corresponding to low differentiation among populations. Among the genotypes group, wild GAM-67 and cultivated Deviraj emerged as the most potent, exhibiting the higher DTI and diverse gene pools. Study exhibited higher total gene diversity in drought-tolerant wild GAM-67 (0.8501) and greater expected heterozygosity (0.626) and gene flow (0.6731) in cultivated Deviraj, underlining their robust genetic adaptability to drought conditions. The integrated approach of field evaluations, in-vitro screening, and molecular analyses explained substantial genetic diversity, with the identification of promising genotypes displaying higher drought tolerance indices, elevated levels of stress-related biochemical osmolytes, and pronounced genetic adaptability, thereby contributing to the advancement of breeding initiatives for enhanced drought resilience in cotton.

Advances in viticulture via smart phenotyping: current progress and future directions in tackling soil copper accumulation

Modern viticulture faces significant challenges including climate change and increasing crop diseases, necessitating sustainable solutions to reduce fungicide use and mitigate soil health risks, particularly from copper accumulation. Advances in plant phenomics are essential for evaluating and tracking phenotypic traits under environmental stress, aiding in selecting resilient vine varieties. However, current methods are limited, hindering effective integration with genomic data for breeding purposes. Remote sensing technologies provide efficient, non-destructive methods for measuring biophysical and biochemical traits of plants, offering detailed insights into their physiological and nutritional state, surpassing traditional methods. Smart phenotyping is essential for selecting crop varieties with desired traits, such as pathogen-resilient vine varieties, tolerant to altered soil fertility including copper toxicity. Identifying plants with typical copper toxicity symptoms under high soil copper levels is straightforward, but it becomes complex with supra-optimal, already toxic, copper levels common in vineyard soils. This can induce multiple stress responses and interferes with nutrient acquisition, leading to ambiguous visual symptoms. Characterizing resilience to copper toxicity in vine plants via smart phenotyping is feasible by relating smart data with physiological assessments, supported by trained professionals who can identify primary stressors. However, complexities increase with more data sources and uncertainties in symptom interpretations. This suggests that artificial intelligence could be valuable in enhancing decision support in viticulture. While smart technologies, powered by artificial intelligence, provide significant benefits in evaluating traits and response times, the uncertainties in interpreting complex symptoms (e.g., copper toxicity) still highlight the need for human oversight in making final decisions.

Physiological and transcriptomic characterization of cold acclimation in endodormant grapevine under different temperature regimes

It is essential for the survival of grapevines in cool climate viticultural regions where vines properly acclimate in late fall and early winter and develop freezing tolerance. Climate change-associated abnormities in temperature during the dormant season, including oscillations between prolonged warmth in late fall and extreme cold in midwinter, impact cold acclimation and threaten the sustainability of the grape and wine industry. We conducted two experiments in controlled environment to investigate the impacts of different temperature regimes on cold acclimation ability in endodormant grapevine buds through a combination of freezing tolerance-based physiological and RNA-seq-based transcriptomic monitoring. Results show that exposure to a constant temperature, whether warm (22 and 11°C), moderate (7°C), or cool (4 and 2°C) was insufficient for triggering cold acclimation and increasing freezing tolerance in dormant buds. However, when the same buds were exposed to temperature cycling (7±5°C), acclimation occurred, and freezing tolerance was increased by 5°C. We characterized the transcriptomic response of endodormant buds to high and low temperatures and temperature cycling and identified new potential roles for the ethylene pathway, starch and sugar metabolism, phenylpropanoid regulation, and protein metabolism in the genetic control of endodormancy maintenance. Despite clear evidence of temperature-responsive transcription in endodormant buds, our current understanding of the genetic control of cold acclimation remains a challenge when generalizing across grapevine tissues and phenological stages.

Glycomolecules: from "sweet immunity" to "sweet biostimulation"?

Climate changes and environmental contaminants are daunting challenges that require an urgent change from current agricultural practices to sustainable agriculture. Biostimulants are natural solutions that adhere to the principles of organic farming and are believed to have low impacts on the environment and human health. Further, they may contribute to reducing the use of chemical inputs while maintaining productivity in adverse environments. Biostimulants are generally defined as formulated substances and microorganisms showing benefits for plant growth, yield, rhizosphere function, nutrient-use efficiency, quality of harvested products, or abiotic stress tolerance. These biosolutions are categorized in different subclasses. Several of them are enriched in glycomolecules and their oligomers. However, very few studies have considered them as active molecules in biostimulation and as a subclass on their own. Herein, we describe the structure and the functions of complex polysaccharides, glycoproteins, and glycolipids in relation to plant defense or biostimulation. We also discuss the parallels between sugar-enhanced plant defense and biostimulation with glycomolecules and introduce the concept of sweet biostimulation or glycostimulation.

Comprehensive evaluation of freezing tolerance in prickly ash and its correlation with ecological and geographical origin factors

Low temperatures are a key factor affecting the growth, development, and geographical distribution of prickly ash. This study investigated the impact of ecological and geographical factors on the freezing tolerance of prickly ash germplasm. Thirty-seven germplasm samples from 18 different origins were collected, and their freezing tolerance was comprehensively evaluated. The correlation between freezing tolerance and the ecological and geographical factors of their origins was also analyzed. Significant differences in freezing tolerance were observed among germplasm from different origins. The semi-lethal temperature of the germplasm ranged from - 12.37 to 1.08 °C. As temperatures decreased, the relative conductivity (REC) and catalase (CAT) activity of the germplasm gradually increased, while soluble sugar (SS), soluble protein (SP), free proline (Pro), and Peroxidase (POD) activities decreased and then increased. Superoxide dismutase (SOD) activity initially increased and then decreased. A comprehensive evaluation of freezing tolerance was conducted using a logistic equation, membership function, and cluster analysis. Germplasm from Tongchuan and Hancheng (Shaanxi Province, China), Asakura (Japan), and Yuncheng (Shanxi Province, China) exhibited the highest freezing tolerance, whereas those from Rongchang (Chongqing Municipality, China), Qujing (Yunnan Province, China), and Honghe (Yunnan Province, China) had the lowest. The correlation analysis revealed a significant positive correlation between freezing tolerance and latitude, and a significant negative correlation with the temperature of origin. Germplasm from higher latitudes showed higher SS content, SOD and CAT activities, stronger antioxidant enzyme activity, and better freezing tolerance compared to those from lower latitudes. REC was lower in germplasm originating from low-temperature areas than in those from high-temperature areas. Additionally, SP, Pro content, SOD, and POD activities were higher, indicating effective scavenging of active oxygen free radicals. No significant correlation was found between altitude and longitude of origin and freezing tolerance. However, at similar latitudes, prickly ash from higher altitudes displayed higher antioxidant enzyme activity and stronger freezing tolerance compared to those from lower altitudes. These findings provide a scientific basis for breeding prickly ash cultivars suited to different ecological regions.

Drought stress mitigation through bioengineering of microbes and crop varieties for sustainable agriculture and food security

Climate change and agriculture are intrinsically connected and sudden changes in climatic conditions adversely impact global food production and security. The climate change-linked abiotic stressors like drought and high temperatures are resulting in crop failure. The most severe abiotic stress drought significantly affect the stomatal closure, production of reactive oxygen species, transpiration, photosynthesis or other physiological processes and plant morphology, and adversely affect plant growth and crop yield. Therefore, there is an exigent need for cost effective and eco-friendly modern technologies to induce drought tolerance in crop plants leading to climate-adapted sustainable agricultural practices for sustained food production. Among many options being pursued in this regard, the use of plant growth promoting microbes (PGPMs) is the most sustainable approach to promote drought stress resilience in crop plants leading to better plant growth and crop productivity. These PGPMs confer drought resistance via various direct or indirect mechanisms including production of antioxidants, enzymes, exopolysaccharides, modulation of phytohormones level, osmotic adjustment by inducing the accumulation of sugars, along with increases in nutrients, water uptake and photosynthetic pigments. However, several technological and ecological challenges limit their use in agriculture and sometimes treatment with plant beneficial microbes fails to produce desired results under field conditions. Thus, development of synthetic microbial communities or host mediated microbiome engineering or development of transgenic plants with the capacity to express desired traits may promote plant survival and growth under drought stress conditions. The present review critically assesses research evidence on the plant growth and stress resilience promoting potentials of PGPMs and their genes as an approach to develop drought resilient plants leading to increased crop productivity. Effective collaboration among scientific communities, policymakers and regulatory agencies is needed to create strong frameworks that both promote and regulate the utilization of synthetic microbial communities and transgenic plants in agriculture.

Unravelling the molecular mechanism underlying drought stress tolerance in Dinanath (Pennisetum pedicellatum Trin.) grass via integrated transcriptomic and metabolomic analyses

Dinanath grass (Pennisetum pedicellatum Trin.) is an extensively grown forage grass known for its significant drought resilience. In order to comprehensively grasp the adaptive mechanism of Dinanath grass in response to water deficient conditions, transcriptomic and metabolomics were applied in the leaves of Dinanath grass exposed to two distinct drought intensities (48-hour and 96-hour). Transcriptomic analysis of Dinanath grass leaves revealed that a total of 218 and 704 genes were differentially expressed under 48- and 96-hour drought conditions, respectively. The genes that were expressed differently (DEGs) and the metabolites that accumulated in response to 48-hour drought stress mainly showed enrichment in the biosynthesis of secondary metabolites, particularly phenolics and flavonoids. Conversely, under 96-hour drought conditions, the enriched pathways predominantly involved lipid metabolism, specifically sterol lipids. In particular, phenylpropanoid pathway and brassinosteroid signaling played a crucial role in drought response to 48- and 96-hour water deficit conditions, respectively. This variation in drought response indicates that the adaptation mechanism in Dinanath grass is highly dependent on the intensity of drought stress. In addition, different genes associated with phenylpropanoid and fatty acid biosynthesis, as well as signal transduction pathways namely phenylalanine ammonia-lyase, putrescine hydroxycinnamoyl transferase, abscisic acid 8'-hydroxylase 2, syntaxin-61, lipoxygenase 5, calcium-dependent protein kinase and phospholipase D alpha one, positively regulated with drought tolerance. Combined transcriptomic and metabolomic analyses highlights the outstanding involvement of regulatory pathways related to secondary cell wall thickening and lignin biosynthesis in imparting drought tolerance to Dinanath grass leaves. These findings collectively contribute to an enhanced understanding of candidate genes and key metabolites relevant to drought response in Dinanath grass. Furthermore, they establish a groundwork for the creation of a transcriptome database aimed at developing abiotic stress-tolerant grasses and major crop varieties through both transgenic and genome editing approaches.

Genome editing prospects for heat stress tolerance in cereal crops

The world population is steadily growing, exerting increasing pressure to feed in the future, which would need additional production of major crops. Challenges associated with changing and unpredicted climate (such as heat waves) are causing global food security threats. Cereal crops are a staple food for a large portion of the world's population. They are mostly affected by these environmentally generated abiotic stresses. Therefore, it is imperative to develop climate-resilient cultivars to support the sustainable production of main cereal crops (Rice, wheat, and maize). Among these stresses, heat stress causes significant losses to major cereals. These issues can be solved by comprehending the molecular mechanisms of heat stress and creating heat-tolerant varieties. Different breeding and biotechnology techniques in the last decade have been employed to develop heat-stress-tolerant varieties. However, these time-consuming techniques often lack the pace required for varietal improvement in climate change scenarios. Genome editing technologies offer precise alteration in the crop genome for developing stress-resistant cultivars. CRISPR/Cas9 (Clustered regularly interspaced short palindromic repeat/Cas9), one such genome editing platform, recently got scientists' attention due to its easy procedures. It is a powerful tool for functional genomics as well as crop breeding. This review will focus on the molecular mechanism of heat stress and different targets that can be altered using CRISPR/Cas genome editing tools to generate climate-smart cereal crops. Further, heat stress signaling and essential players have been highlighted to provide a comprehensive overview of the topic.

Chitosan-thiourea and their derivatives: Applications and action mechanisms for imparting drought tolerance

The increasing abiotic stresses from changing global climatic conditions, including drought, extreme temperatures, salinity, storms, pollutants, and floods, impend crop cultivation and sustainability. To mitigate these effects, numerous synthetic and non-synthetic chemicals or plant growth regulators are in practice. Chitosan, a natural organic substance rich in nitrogen and carbon, and thiourea, a synthetic plant growth regulator containing sulfur and nitrogen, have garnered significant interest for their roles in enhancing plant stress tolerance. Despite extensive use, the precise mechanisms of their actions remain unclear. Towards this endeavor, the present review examines how chitosan and thiourea contribute to stress tolerance in crop plants, particularly under drought conditions, to improve production and sustainability. It also explores thiourea's potential as a hydrogen sulfide (H2S) donor and the possible applications of thiolated chitosan derivatives and chitosan-thiourea combinations, emphasizing their biological functions and benefits for sustainable agriculture.

Examining the impact of climate change on cereal production in India: Empirical evidence from ARDL modelling approach

Agriculture sector is major sufferer of climate change both at a global level as well as at India level. Cereals account for about 92 % of India's total food grain output and climate change has a significant influence on the production of cereals. This study aimed to evaluate the long-term and short-term effects of climatic and non-climatic variables, specifically temperature, precipitation, cereal area, total cropped area, fertilizer consumption, and pesticide consumption, on cereal production in India. The study included annual time series data that covered the period from 1960 to 2018, covering a period of 58 years. Various econometric techniques were employed to examine these relationships. The validity of a long-term and short-term relationship among the relevant variables included in the study was validated by employing the Autoregressive Distributed Lag (ARDL) technique and the Johansen cointegration test. The ARDL model's estimation outcomes reveals that input factors such as cereal area became a key factor in rising cereal production, as evidenced by its positive coefficient. Similarly, fertilizer consumption and precipitation had positive effects on production in the long run whereas total cropped area and minimum temperature has little influence over the results of production both in short run as well as long run. Furthermore, the long-term findings were also supported using econometric tools like Canonical Cointegrating Regression (CCR) and Fully Modified Least Squares (FMOLS). These methods confirmed that variations in cereal production in India were significantly influenced by both climatic factors and agricultural inputs and factors. The study emphasizes the urgency for policymakers to prioritize proactive measures aimed at reducing the adverse impacts of climate change on cereal production in India. This necessitates a comprehensive strategy integrating sustainable practices, technological innovations, and robust policy frameworks to ensure resilient agricultural sectors and sustainable food production.

Near future variations in temperature extremes in northeastern Iran under CMIP6 projections

Extreme air temperatures which are of significance in plant growth are influenced by climate change. The aim of this study was to assess the climate change effects on temperature extreme indices (TEIs) in northeastern Iran based on the CMIP6 projections. For this purpose, five extreme indices including maximum of maximum temperature (TXx), minimum of minimum temperature (TNn), cold nights (TN10p), warm nights (TN90p), and summer days (SU25) which are effective on plant growth were evaluated. The projections of the three Earth system models including ACCESS-CM2, MIROC6, and MRI-ESM2-0 were assessed under the three scenarios of SSP1-2.6, SSP2-4.5, and SSP5-8.5 for the period 2026-2050 compared to the historical period (1989-2014). The models' projections were evaluated by statistical tests on the changes in the average and trend of data. Results showed that the MRI-ESM2-0 model revealed the best efficiency compared to the other models. The projections of all models and scenarios indicated a significant increase in the average of TXx and SU25 indices over the study area at the confidence level of 95% by 1.6 to 2.4 °C, as well as 15 to 18 days under the three scenarios. Also, the results exhibited a significant increasing trend in TN90p and a decreasing one in TN10p overall province at confidence level of 95%. These changes will lead to an increase in evapotranspiration of the plants and an increase in agricultural water demand, and as a result, a decrease in the yield of some main products like wheat and saffron which are the main products in the study area.

Mineral, seed morphology, and agronomic characteristics of proso millet grown in the inland Pacific Northwest

Climate change increases stressors that will challenge the resiliency of global agricultural production. Just three crops, wheat, maize, and rice, are estimated to sustain 50% of the caloric demand of the world population, meaning that significant loss of any of these crops would threaten global food security. However, increasing cropping system diversity can create a more resilient food system. One crop that could add diversity to wheat-dominated cropping systems in the inland Pacific Northwest is proso millet, a climate-resilient, small-seeded cereal crop that is highly water efficient, able to grow in low fertility soils, and has a desirable nutritional profile. Proso millet shows potential for adoption in this region due to its short growing season, compatibility with regional equipment, and environmental requirements, however US cultivars have been developed for the Great Plains and little research has been conducted outside of this region. To better understand the potential for adoption in the inland PNW, seven commercially available varieties were planted in a researcher-run trial in Pullman, WA and in a series of producer-run trials across the region in 2022. Samples were analyzed for mineral concentration (Zn, Fe, Cu, Mn, Mg, Ca, P, and K), seed morphology phenotypes (seed area, seed eccentricity, thousand seed weight, and seed color), and agronomic phenotypes (grain yield, plant height, days to heading, days to maturity, and percent emergence). Varieties from the researcher-run trial showed significant differences for all traits excluding percent emergence. Samples from producer-run trials showed differences by location for concentration of all minerals and for all seed morphology traits but were not analyzed for agronomic phenotypes. Samples from producer-run trials showed no difference by variety for mineral concentration but showed varietal differences for all seed morphology phenotypes. Most minerals were positively correlated with one another (0.28 < r < 0.92). Grain yield was negatively correlated with Zn (r = -0.55, p < 0.01) and was positively correlated with plant height (r = 0.62, p < 0.001), seed area (r = 0.45, p < 0.05), and thousand seed weight (r = 0.45, p < 0.05). Results from this study can inform variety selection for stakeholders interested in adopting proso millet in the inland PNW and can support future proso millet breeding efforts, particularly in this region.

Expression patterns of candidate genes for the Lr46/Yr29 "slow rust" locus in common wheat (Triticum aestivum L.) and associated miRNAs inform of the gene conferring the Puccinia triticina resistance trait

Leaf rust caused by Puccinia triticina (Pt) is one of the most impactful diseases causing substantial losses in common wheat (Triticum aestivum L.) crops. In adult plants resistant to Pt, a horizontal adult plant resistance (APR) is observed: APR protects the plant against multiple pathogen races and is distinguished by durable persistence under production conditions. The Lr46/Yr29 locus was mapped to chromosome 1B of common wheat genome, but the identity of the underlying gene has not been demonstrated although several candidate genes have been proposed. This study aimed to analyze the expression of nine candidate genes located at the Lr46/Yr29 locus and their four complementary miRNAs (tae-miR5384-3p, tae-miR9780, tae-miR9775, and tae-miR164), in response to Pt infection. The plant materials tested included five reference cultivars in which the molecular marker csLV46G22 associated with the Lr46/Yr29-based Pt resistance was identified, as well as one susceptible control cultivar. Biotic stress was induced in adult plants by inoculation with fungal spores under controlled conditions. Plant material was sampled before and at 6, 12, 24, 48 hours post inoculation (hpi). Differences in expression of candidate genes at the Lr46/Yr29 locus were analyzed by qRT-PCR and showed that the expression of the genes varied at the analyzed time points. The highest expression of Lr46/Yr29 candidate genes (Lr46-Glu1, Lr46-Glu2, Lr46-Glu3, Lr46-RLK1, Lr46-RLK2, Lr46-RLK3, Lr46-RLK4, Lr46-Snex, and Lr46-WRKY) occurred at 12 and 24 hpi and such expression profiles were obtained only for one candidate gene among the nine genes analyzed (Lr46-Glu2), indicating that it may be a contributing factor in the resistance response to Pt infection.

Pulsed high power microwave seeds priming modulates germination, growth, redox homeostasis, and hormonal shifts in barley for improved seedling growth: Unleashing the molecular dynamics

Increasing the seed germination potential and seedling growth rates play a pivotal role in increasing overall crop productivity. Seed germination and early vegetative (seedling) growth are critical developmental stages in plants. High-power microwave (HPM) technology has facilitated both the emergence of novel applications and improvements to existing in agriculture. The implications of pulsed HPM on agriculture remain unexplored. In this study, we have investigated the effects of pulsed HPM exposure on barley germination and seedling growth, elucidating the plausible underlying mechanisms. Barley seeds underwent direct HPM irradiation, with 60 pulses by 2.04 mJ/pulse, across three distinct irradiation settings: dry, submerged in deionized (DI) water, and submerged in DI water one day before exposure. Seed germination significantly increased in all HPM-treated groups, where the HPM-dry group exhibited a notable increase, with a 2.48-fold rise at day 2 and a 1.9-fold increment at day 3. Similarly, all HPM-treated groups displayed significant enhancements in water uptake, and seedling growth (weight and length), as well as elevated levels of chlorophyll, carotenoids, and total soluble protein content. The obtained results indicate that when comparing three irradiation setting, HPM-dry showed the most promising effects. Condition HPM seed treatment increases the level of reactive species within the barley seedlings, thereby modulating plant biochemistry, physiology, and different cellular signaling cascades via induced enzymatic activities. Notably, the markers associated with plant growth are upregulated and growth inhibitory markers are downregulated post-HPM exposure. Under optimal HPM-dry treatment, auxin (IAA) levels increased threefold, while ABA levels decreased by up to 65 %. These molecular findings illuminate the intricate regulatory mechanisms governing phenotypic changes in barley seedlings subjected to HPM treatment. The results of this study might play a key role to understand molecular mechanisms after pulsed-HPM irradiation of seeds, contributing significantly to address the global need of sustainable crop yield.

Exogenous Melatonin Enhances Moisture Stress Tolerance in Mango (Mangifera indica L.) through Alleviating Oxidative Damages

In subtropical regions, April to June represents a temporary moisture stress for mango trees, leading to huge economic loss. Although water is available in the deep root zone, the upper soil surface, which has fibrous roots, is dry, and the tree transpiration rate is high. Moisture stress causes an increased oxidation state, which is detrimental to fruit growth and development. Finding substitutes for moisture stress management is important for sustainable mango production. To manage this moisture stress in mango, we tested if foliar application of 20, 50, 100 and 150 μM melatonin helped to maintain a reduced oxidation state in the cells. Applications were made at three phenological stages of fruit development (marble, egg and mature fruit stages) in 16-year-old trees and the same plants for each treatment were followed over three years. Melatonin application indeed improved the fruit yield of mango. Moisture stress decreased yield by 55.94% compared to irrigated trees but only by 7.5% in melatonin treatment. Also, more 'A' grade fruits were harvested in irrigated and melatonin-treated conditions than in non-irrigated and non-treated conditions. Indeed, the total chlorophyll content in the leaves of moisture-stressed melatonin-treated trees (12.58 mg.g-1 fresh weight) was well above non-treated trees (6.77 mg.g-1) and similar to irrigated trees (12.50 mg.g-1). A dose-dependent increase in the chlorophyll content of melatonin-treated plants was found. Similarly, the activities of catalase, peroxidase, superoxidase dismutase enzymes in leaves of irrigated and melatonin-treated trees were lower than in non-irrigated condition, and superoxide free radial formation was lower in moisture-stressed melatonin-treated trees (0.77 nmol H2O2.mg-1 protein) and irrigated trees (0.65) than moisture-stressed non-treated trees (4.27). Significant variations was found in antioxidants (total, reduced and oxidized glutathione and ascorbate) content and antioxidant enzymes' activities (i.e., glutathione reductase and ascorbate peroxidase) in irrigated, melatonin-treated and non-irrigated conditions. Overall, 150 μM exogenous melatonin applied three times at different fruit development stages may be a sustainable and useful approach to manage transient moisture stress in mango trees thanks to its positive action on the antioxidant system.

Biological pest regulation can benefit from diverse predation modes

Increases in agricultural intensity due to anthropogenic demands alongside the need to reduce the reliance on pesticides have resulted in an urgent need for sustainable options for pest control. Biological pest regulation is an alternative strategy that relies on natural predators and is essentially a by-product of successful foraging. Therefore, knowledge of the predator's specific foraging behaviour can significantly improve bioregulation. In this article, we discuss the implications of predators' diverse foraging modes on their efficiency as bioregulators of crop pests using amphibians and reptiles as models. Amphibians and reptiles are promising bioregulators as they are insectivorous, and the diversity in their foraging styles-ambush and active foraging, differing in energy expenditure, movement, cognitive abilities, reliance on cues, response to predatory risk, competition and prey salience-can have specific impacts on pest regulation. We propose the uptake of this concept into strategizing pest management actions. We are now moving towards an era of biological pest regulation, which is the most targeted, economically profitable method with zero negative impact on the ecosystem. Utilizing diverse traits associated with the different foraging modes in vertebrate predators can be a crucial tool in allowing pest management to adapt to the extreme challenges it is facing.

Adaptive roles of cytokinins in enhancing plant resilience and yield against environmental stressors

Innovative agricultural strategies are essential for addressing the urgent challenge of food security in light of climate change, population growth, and various environmental stressors. Cytokinins (CKs) play a pivotal role in enhancing plant resilience and productivity. These compounds, which include isoprenoid and aromatic types, are synthesized through pathways involving key enzymes such as isopentenyl transferase and cytokinin oxidase. Under abiotic stress conditions, CKs regulate critical physiological processes by improving photosynthetic efficiency, enhancing antioxidant enzyme activity, and optimizing root architecture. They also reduce the levels of reactive oxygen species and malondialdehyde, resulting in improved plant performance and yield. CKs interact intricately with other phytohormones, including abscisic acid, ethylene, salicylic acid, and jasmonic acid, to modulate stress-responsive pathways. This hormonal cross-talk is vital for finely tuning plant responses to stress. Additionally, CKs influence nutrient uptake and enhance responses to heavy metal stress, thereby bolstering overall plant resilience. The application of CKs helps plants maintain higher chlorophyll levels, boost antioxidant systems, and promote root and shoot growth. The strategic utilization of CKs presents an adaptive approach for developing robust crops capable of withstanding diverse environmental stressors, thus contributing to sustainable agricultural practices and global food security. Ongoing research into the mechanisms of CK action and their interactions with other hormones is essential for maximizing their agricultural potential. This underscores the necessity for continued innovation and research in agricultural practices, in alignment with global goals of sustainable productivity and food security.

Development of Rice Mutants with Enhanced Resilience to Drought Stress and Their Evaluation by Lab Assay, Field, and Multivariate Analysis

Drought is one of the foremost devastating abiotic stresses reported for rice crops. To improve the productivity of rice, diversity is being enlarged by induced mutation using a source of gamma rays. But this type of mutation rarely results in fruitful products because the chances of getting the desired mutant are very low. The present study aimed to evaluate the rice mutants against drought or osmotic stress. In this study, three experiments were conducted that comprised of seventy-one mutants originating from different doses of gamma rays (Cs137) along with parent RICF-160 and commercial variety (Kainat) were tested. In the first experiment, germination and seedling attributes were calculated under control and osmotic stress conditions created by using 16% (0.6 MPa) polyethylene glycol (PEG-6000). Results revealed that all the mutants exhibited significant (p < 0.01) responses to PEG-induced osmotic stress. Principal component biplot analysis (PCBA) revealed the first seventeen cumulative PCs with eigenvalues >1 contributed 88%. It was noted that the germination percentage (GP), germination rate (GR), coefficient velocity of germination (CVG), and seed vigor (SV) contributed maximum and positively in PC1. Results showed the highest germination percentage (GP) at 48 hrs in mutant NMSF-11 (88.9%) followed by NMSf-38 (73.3%). Similarly, the germination rate (GR) and coefficient velocity of germination (CVG) were measured highest in NMSF-11 (9.7 and 118.1%), respectively. In stress conditions, the mutants NMSF-35 and NMSF-36 depicted the highest GP, GR, and CVG. The maximum seed vigor (SV), shoot length (SL), root length (RL), and fresh weight (FW) were observed in mutants NMSF-50 and NMSF-51 under both conditions, whereas the mutants NMSF-59, NMSF-60, NMSF-64, and NMSF-67 showed lower values for SV, SL, RL, and FW. In the second experiment, a field trial was conducted at the Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, in two control and stress sets. A bit different trend was observed among all mutants for agronomic parameters under both conditions. In the third experiment, biochemical profiling was done in Marker Assisted Breeding (MAB) Lab-1, Plant Breeding and Genetics Division. A significant variation was seen in enzymatic antioxidants and chlorophyll content in both control and stress conditions. Under control conditions, the ascorbate peroxidase (APX) content was observed higher in mutant NMSF-49 (106.07 Units/g. f. wt.). In comparison with the stress, the ascorbate peroxidase activity was higher in NMSF-41 (82.34 Units/g. f. wt.). Catalase (CAT) activity was observed maximum in NMSF-29 (17.54 Units/g. f. wt.) and NMSF-40 (14.17 Units/g. f. wt.) under control and stress conditions, respectively. Peroxidase (POD) activity was observed maximum in NMSF-51 (22.55 Units/g. f. wt. and 10.84 Units/g. f. wt.) under control and stress conditions, respectively. In conclusion, to fit in the changing climate conditions for resilient rice crop production, the promising mutant lines may be used to transfer the desirable drought-tolerant/drought-resistant genes in rice germplasm.

Integrated Review of Transcriptomic and Proteomic Studies to Understand Molecular Mechanisms of Rice's Response to Environmental Stresses

Rice (Oryza sativa L.) is grown nearly worldwide and is a staple food for more than half of the world's population. With the rise in extreme weather and climate events, there is an urgent need to decode the complex mechanisms of rice's response to environmental stress and to breed high-yield, high-quality and stress-resistant varieties. Over the past few decades, significant advancements in molecular biology have led to the widespread use of several omics methodologies to study all aspects of plant growth, development and environmental adaptation. Transcriptomics and proteomics have become the most popular techniques used to investigate plants' stress-responsive mechanisms despite the complexity of the underlying molecular landscapes. This review offers a comprehensive and current summary of how transcriptomics and proteomics together reveal the molecular details of rice's response to environmental stresses. It also provides a catalog of the current applications of omics in comprehending this imperative crop in relation to stress tolerance improvement and breeding. The evaluation of recent advances in CRISPR/Cas-based genome editing and the application of synthetic biology technologies highlights the possibility of expediting the development of rice cultivars that are resistant to stress and suited to various agroecological environments.

Impact of Agricultural Activities on Climate Change: A Review of Greenhouse Gas Emission Patterns in Field Crop Systems

This review paper synthesizes the current understanding of greenhouse gas (GHG) emissions from field cropping systems. It examines the key factors influencing GHG emissions, including crop type, management practices, and soil conditions. The review highlights the variability in GHG emissions across different cropping systems. Conventional tillage systems generally emit higher levels of carbon dioxide (CO2) and nitrous oxide (N2O) than no-till or reduced tillage systems. Crop rotation, cover cropping, and residue management can significantly reduce GHG emissions by improving soil carbon sequestration and reducing nitrogen fertilizer requirements. The paper also discusses the challenges and opportunities for mitigating GHG emissions in field cropping systems. Precision agriculture techniques, such as variable rate application of fertilizers and water, can optimize crop production while minimizing environmental impacts. Agroforestry systems, which integrate trees and crops, offer the potential for carbon sequestration and reducing N2O emissions. This review provides insights into the latest research on GHG emissions from field cropping systems and identifies areas for further study. It emphasizes the importance of adopting sustainable management practices to reduce GHG emissions and enhance the environmental sustainability of agricultural systems.

Functional prediction based on 16S rRNA metagenome data from bacterial microbiota associated with macroalgae from the Peruvian coast

Macroalgae are vital reservoirs for essential epibiotic microorganisms. Among these are growth-promoting bacteria that support the growth and healthy development of their host macroalgae, and these macroalgae can be utilized in agriculture as biostimulants, offering an alternative to traditional agrochemicals. However, to date, no comparative studies have been conducted on the functional profile and bacterial diversity associated with coastal macroalgae of Peru. In this study, we employed amplicon sequencing of the V3-V4 region of 16S rRNA gene in twelve host macroalgae collected from two rocky shores in central Peru to compare their bacterial communities. The results revealed high bacterial diversity across both sites, but differences in microbial composition were noted. The phyla Bacteroidota and Pseudomonadota were predominant. The functional prediction highlighted 44 significant metabolic pathways associated with the bacterial microbiota when comparing host macroalgae. These active pathways are related to metabolism and genetic and cellular information processing. No direct association was detected between the macroalgal genera and the associated microbiota, suggesting that the bacterial community is largely influenced by their genetic functions than the taxonomic composition of their hosts. Furthermore, some species of Chlorophyta and Rhodophyta were observed to host growth-promoting bacteria, such as Maribacter sp. and Sulfitobacter sp.

Enhancing stress resilience in soybeans (Glycine max): assessing the efficacy of priming and cross-priming for mitigating water deficit and waterlogging effects

Priming enables plants to respond more promptly, minimise damage, and survive subsequent stress events. Here, we aimed to assess the efficacy of priming and cross-priming in mitigating the stress caused by waterlogging and/or dehydration in soybeans (Glycine max ). Soybean plants were cultivated in a greenhouse in plastic pots in which soil moisture was maintained at pot capacity through irrigation. The first stress was applied in plants at the vegetative stage for 5days and involved either dehydration or waterlogging, depending on the treatment. Subsequently, the plants were irrigated or drained and maintained at pot capacity until the second stress. For the second stress, the conditions were repeated in plants at the reproductive stage. We then evaluated the levels of hydrogen peroxide (H2 O2 ), lipid peroxidation, total soluble sugars (TSS), amino acids, proline, and starch, and the activity of antioxidant, fermentative, and aminotransferase enzymes. Under waterlogging and dehydration, priming and cross-priming significantly increased the activity of antioxidant enzymes and the levels of TSS, amino acids, and proline while reducing H2 O2 concentration and lipid peroxidation. Under waterlogging, priming suppressed fermentative activity and increased carbohydrate content. This demonstrates that soybean plants activate their defence systems more promptly when subjected to priming.

Harnessing landrace diversity empowers wheat breeding

Harnessing genetic diversity in major staple crops through the development of new breeding capabilities is essential to ensure food security1. Here we examined the genetic and phenotypic diversity of the A. E. Watkins landrace collection2 of bread wheat (Triticum aestivum), a major global cereal, by whole-genome re-sequencing of 827 Watkins landraces and 208 modern cultivars and in-depth field evaluation spanning a decade. We found that modern cultivars are derived from two of the seven ancestral groups of wheat and maintain very long-range haplotype integrity. The remaining five groups represent untapped genetic sources, providing access to landrace-specific alleles and haplotypes for breeding. Linkage disequilibrium-based haplotypes and association genetics analyses link Watkins genomes to the thousands of identified high-resolution quantitative trait loci and significant marker-trait associations. Using these structured germplasm, genotyping and informatics resources, we revealed many Watkins-unique beneficial haplotypes that can confer superior traits in modern wheat. Furthermore, we assessed the phenotypic effects of 44,338 Watkins-unique haplotypes, introgressed from 143 prioritized quantitative trait loci in the context of modern cultivars, bridging the gap between landrace diversity and current breeding. This study establishes a framework for systematically utilizing genetic diversity in crop improvement to achieve sustainable food security.