TL;DR
The validated hub genes may serve as promising candidate targets for the development of functional markers in marker-assisted selection (MAS), potentially facilitating early-stage screening and pyramiding of drought-tolerant alleles in barley breeding programs, pending experimental validation.
Overall, transcription factors from the DREB, NAC, MYB, and WRKY families are still considered the primary regulatory targets, but CRISPR/Cas-based gene editing is now able to provide precise, multiplex gene modifications in polyploid wheat.
Drought inhibits grass development and survival. However, molecular-based studies on drought tolerance mechanisms in bermudagrass (Cynodon dactylon) remain scarce. Therefore, a drought-resistant bermudagrass (Tianshui) and a drought-sensitive (Zhengzhou) genotype were selected and subjected to 28 days of 50% drought stress. Leaves were sampled for RNA sequencing. Under drought stress, 2410 differentially expressed genes (DEGs) were discovered in which 1214 were upregulated (tolerant vs. sensitive) and 1196 downregulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that these specific DEGs are notably present in hormonal signal transduction pathways, flavonoids biogenesis, carbohydrate metabolic processes, abscisic acid-mediated pathways, MAPK signaling, and gluconeogenesis. Additionally, the plant hormone signal transduction pathway is predominantly linked to abscisic acid signal transduction, and many other plant hormones were also drought-responsive. The study specifically targeted genes associated with the antioxidant enzyme system, with a particular emphasis on responsive TFs such as MYB, bHLH, bZIP, GRAS, and WRKY. This study establishes the theoretical framework and identifies gene sources for the genetic enhancement and breeding of bermudagrass in the future.
Soybean is an indispensable crop supplying protein and oil for humans and animals, and playing an essential role in global food security. Drought represses soybean seed germination, reducing biomass accumulation and even inhibiting yield. In order to dissect the genetic components underlying soybean drought tolerance during different development stage, a natural population containing 140 accessions was employed to evaluate seven drought tolerance-related traits under water-welled and drought stress conditions. Subsequently, genome-wide association study (GWAS) was conducted based on 150K single nucleotide polymorphism (SNP) markers of “Zhongdouxin-1”. And the drought tolerance coefficient of seven different traits were analyzed with seven GWAS models. A total of 1807 significant SNPs were detected across 20 chromosome, including 569 SNPs for germination stage, and 1242 SNPs for seedling stage. Of 569 SNPs identified in germination stage, 354 SNPs on chromosomes 2, 7, 13, 14, and 17 accounting for 62.21%. Among 1242 SNPs found in seedling stage, 869 SNPs on chromosomes 11, 14, 15, 17 and 18 accounting for 69.97%. Moreover, among 1807 significant SNPs, 163 SNPs exhibited pleiotropic effects, of which 23 were located in exon, 21 in intron, 12 in 5’UTR or 3’UTR and 11 in upstream or downstream. Furthermore, 249 stable SNPs were detected by more than four GWAS models. According to these stable SNPs, RNA expression levels and gene annotations, four causal genes ( Glyma.02G080200 , Glyma.11G056200 , Glyma.12G188900 , and Glyma.18G110200 ) conferring soybean drought tolerance were detected, which participated in ethylene stimulus response, water deprivation response, and proteolysis. Collectively, 249 stable SNPs, 163 pleiotropic SNPs and four candidate genes identified in present study provided promising molecular resources and reliable foundation for drought resistance improvement and marker-assisted selective breeding in soybean.
In natural environments, plants are often exposed to multiple abiotic stresses simultaneously. Their combined effects usually cause more severe damage than a single stress. However, little is known about the coordinated response mechanisms of cool-season turfgrass to combined drought and cold stress. Two accessions of Annual bluegrass (Poa annua L.) with contrasting stress tolerance were used in this study: Huangzhong (HZ, tolerant) and Zhouqu (ZQ, sensitive). Physiological phenotyping, stomatal behavior observation, transcriptomics, and metabolomics were integrated to systematically compare their responses to drought, cold, and combined stress. The aim was to reveal the physiological and molecular regulatory differences between the two accessions and to identify the core pathways underlying combined stress responses. Results showed that combined stress significantly aggravated photosynthetic inhibition and oxidative damage. The sensitive accession ZQ exhibited much greater damage than the tolerant accession HZ. Transcriptomic and metabolomic analyses identified 11,440 and 13,631 differentially expressed genes, as well as 2585 and 2642 differentially accumulated metabolites in HZ and ZQ, respectively, under combined stress. Weighted gene co-expression network analysis (WGCNA) identified a core module (MEred) significantly correlated with photosynthetic efficiency and antioxidant capacity, with HCT and PAL as candidate hub genes. Meanwhile, multi-omics integration revealed that phenylpropanoid biosynthesis was strongly activated only in the tolerant accession HZ, and clustering analysis further demonstrated that the molecular profiles under combined stress closely resembled those under drought stress alone. This study provides new insights into the coordinated regulatory network of cool-season turfgrass in response to multiple abiotic stresses. It also offers potential targets for genetic improvement and functional utilization of stress-tolerance genes.
Drought is a major abiotic stress threatening plant productivity and agricultural sustainability, yet the molecular mechanisms underlying adaptive root responses to water deficit in the water use strategies continuum remain insufficiently understood, particularly in perennial crops. In this study, we explored drought responses in nine accessions belonging to three wild Vitis species (V. acerifolia, V. candicans, and V. doaniana) displaying variying drought-response strategies. Plants were subjected to moderate drought stress (40% soil water content) for three weeks under greenhouse conditions. By integrating physiological, metabolic, and transcriptomic analyses, we aimed to identify both conserved and species-specific mechanisms associated with drought adaptation. Differential expression analyses revealed a conserved core set of drought-responsive genes shared among species, including genes involved in abscisic acid signaling, reactive oxygen species detoxification, solute transport, and plant defense. In parallel, each species exhibited distinct transcriptional and metabolic signatures reflecting alternative adaptive strategies related to osmoregulation, and oxidative stress mitigation. Weighted gene co-expression network analysis (WGCNA) further revealed significant associations between constitutive, non-plastic gene expression and root phenotypic traits. Overall, our findings demonstrate that wild Vitis species rely on both conserved stress-responsive pathways and species-specific constitutive regulation to cope with drought stress. These results highlight the importance of root-associated traits and intrinsic regulatory networks in shaping drought adaptation and provide new targets for the development of drought-resilient grapevine rootstocks.
BACKGROUND Drought stress is a major environmental constraint limiting mungbean productivity, particularly in arid and semi-arid regions. However, the molecular mechanisms underlying drought tolerance in mungbean remain poorly understood. MicroRNAs (miRNAs), which function as important post-transcriptional regulators of gene expression, play critical roles in modulating plant responses to abiotic stresses. This study aimed to identify drought-responsive miRNAs and elucidate their regulatory roles in contrasting mungbean genotypes under drought stress. RESULTS Seven widely cultivated mungbean genotypes were evaluated under controlled drought stress conditions using physiological, molecular, and yield-related parameters. Traits including root and shoot length, biomass accumulation, nodule number, expression of drought-responsive genes under prolonged stress (30 days), and yield attributes were assessed. Based on these analyses, genotype cv. ML267 was identified as drought tolerant, whereas cv. PDM139 was identified as drought susceptible. To investigate the molecular basis of drought tolerance, small RNA sequencing was performed using root tissues of the contrasting genotypes. A total of 61 novel drought-responsive miRNAs and 274 conserved miRNA homologs were identified, showing genotype-specific differential expression under drought stress conditions. Quantitative RT-PCR validation of selected miRNAs and their predicted target genes demonstrated inverse expression patterns, confirming miRNA-mediated post-transcriptional regulation. Functional annotation and network analyses revealed that these miRNA-target regulatory modules are associated with hormone signaling, antioxidant defense, root development, and stress adaptation pathways. The study also revealed complex miRNA-mediated regulatory networks that regulate mungbean gene expression in response to drought. CONCLUSIONS This study offers a thorough understanding of small RNA-mediated regulation associated with drought tolerance in mungbean. The identified drought-responsive miRNAs along with their target genes indicate potential molecular candidates for enhancing drought resistance and could aid in the creation of climate-resilient mungbean varieties through molecular breeding and biotechnological methods.