Aug 2026· Physiologia Plantarum : An International Journal for Plant Biology· Vol 178 5, pp.
e71084
· 0 citations· 55 references
Medicine
TL;DR
This study establishes the theoretical framework and identifies gene sources for the genetic enhancement and breeding of bermudagrass in the future by targeting genes associated with the antioxidant enzyme system, with a particular emphasis on responsive TFs such as MYB, bHLH, bZIP, GRAS, and WRKY.
Abstract
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.
Cliff habitats are characterized by limited and heterogeneous water availability, requiring plants to develop adaptive strategies to cope with drought stress. Opisthopappus longilobus, a cliff-endemic Asteraceae species restricted to the Taihang Mountains of northern China, has evolved under persistent water-limited conditions and represents a valuable model for investigating the molecular mechanisms underlying drought adaptation. However, the transcriptional regulatory networks involved in its drought response remain largely unexplored. In this study, we performed RNA sequencing of O. longilobus leaves under control and drought conditions to investigate drought-responsive regulatory networks. Six RNA-seq libraries were generated, and a total of 5260 differentially expressed genes (DEGs) were identified in response to drought stress. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that these DEGs were mainly associated with phytohormone signal transduction, stress-responsive regulation, defense responses, metabolic reprogramming, and transcriptional regulation. Notably, multiple transcription factor families, including MYB, ERF, and ABF, were enriched among drought-responsive genes, suggesting their involvement in drought adaptation. Furthermore, quantitative RT-PCR was used to validate the RNA-seq results. Among the drought-responsive transcription factors, an R2R3-MYB transcription factor, OlMYB35, was identified as a candidate regulator and was further demonstrated to play a positive role in drought response through transient transformation assays. Taken together, this study provides new insights into drought-responsive regulatory mechanisms in O. longilobus and identifies OlMYB35 as a promising candidate gene for further functional validation and potential application in stress-resilient chrysanthemum breeding.
Ruyue Jing, Yaru Zhang, Xiao-Jin Su et al.· Horticulturae· 0 citations
New insights are provided into the coordinated regulatory network of cool-season turfgrass in response to multiple abiotic stresses and it offers potential targets for genetic improvement and functional utilization of stress-tolerance genes.
Juanxia Li, Fu Ran, Chunling Deng et al.· Plant physiology and biochem...· 0 citations
Drought stress significantly constrains plant productivity in arid and semi-arid habitats. Understanding the molecular pathways of drought tolerance is essential for germplasm enhancement and ecological restoration. This study investigated the drought adaptation mechanisms of Juniperus sabina L., an ecologically vital evergreen shrub, using integrated physiological, transcriptomic, and metabolomic analyses. Under extreme drought stress, the drought-tolerant provenance (DBD) demonstrated superior photosynthetic stability and robust antioxidant capacity compared to the drought-sensitive provenance (WDH). WDH exhibited significant photosystem impairment and membrane degradation, indicated by elevated relative electrical conductivity and malondialdehyde levels. Integrated analysis identified phenylpropanoid and flavonoid biosynthesis as critical pathways for adaptation. Notably, the DBD provenance utilized a specific metabolic reprogramming strategy, potentially mediated by the transcription factor CONSTANS-LIKE 6 (COL6). This regulatory mechanism involved down-regulating upstream biosynthetic genes (e.g., 4CL, CHS) while activating downstream modification genes (e.g., UGT, COMT-2). This shift redirected metabolic flux toward the accumulation of specific antioxidant flavonoids, such as syringetin, while maintaining cellular structural integrity. Our findings reveal a COL6-mediated regulatory network that coordinates metabolic flux redistribution and stress adaptation in J. sabina. Furthermore, transient overexpression of JsCOL6 in Nicotiana benthamiana confirmed its nuclear localization and demonstrated that it significantly enhanced drought tolerance. JsCOL6-overexpressing plants exhibited robust antioxidant capacity under PEG-induced drought stress, which was molecularly coupled with the transcriptional up-regulation of the downstream peroxidase gene (NbPER-1) and elevated activities of antioxidant enzymes. These results highlight promising molecular targets for breeding drought-resistant conifers and optimizing secondary metabolite production in marginal environments.
Xue-Jie Zhang, Xu-Hong Wang, Rong Li et al.· Plant physiology and biochem...· 0 citations
Drought and salinity are major abiotic stresses that restrict crop productivity by disrupting water relations, ion balance, cellular metabolism, and gene regulation. This study investigated the molecular and genetic responses associated with these stresses using the publicly available rice transcriptomic dataset GSE21651 from the NCBI Gene Expression Omnibus. The analysis included 16 samples representing control, drought, and salinity conditions and 57,381 probe sets. Genome-wide differential-expression analysis revealed that 23,506 probe sets (40.96%) were significant at adjusted P < 0.05, indicating extensive transcriptional reprogramming under stress. Exploratory expression profiling and UMAP analysis further demonstrated distinct global expression patterns among control, drought, and salinity groups. Functional interpretation of significant genes identified major stress-responsive components involved in water transport, osmotic protection, ABA-mediated signalling, antioxidant defence, metabolic adjustment, and transcriptional regulation. Important candidate genes included aquaporins, late embryogenesis abundant proteins, dehydrins, antioxidant enzymes, and WRKY, NAC, MYB, and bZIP transcription factors. The findings demonstrate that drought and salinity tolerance in rice is governed by coordinated molecular networks involving both shared and stress-specific responses. These results highlight the value of transcriptomic analysis for identifying candidate genes that can support marker-assisted breeding, genetic engineering, and genome-editing strategies aimed at developing climate-resilient crops.
Biju Sidharthan, P. V. Pulate, Misha Yadav et al.· Genetics and Molecular Resea...· 0 citations
Narenga porphyrocoma, a wild relative of sugarcane with high drought tolerance, is a valuable germplasm resource for mining drought-tolerance genes. Weighted gene co-expression network analysis (WGCNA) identified NpWRKY38, a WRKY transcription factor that was significantly down-regulated under drought stress, a response that was further recapitulated by exogenous abscisic acid (ABA) treatment and consistent with the presence of ABA-responsive elements in its promoter. NpWRKY38 overexpression in rice resulted in a significant increase in endogenous ABA content, yet led to insufficient stomatal closure, an attenuated response to exogenous ABA, and a significant reduction in drought tolerance. Transcriptomic analysis revealed that stress-related signaling pathways (e.g., MAPK signaling and plant hormone signal transduction) were activated in the OE lines, whereas photosynthesis, carbon fixation, and chlorophyll biosynthesis pathways were globally suppressed. Specifically, the ABA biosynthetic gene NCED was up-regulated, whereas the positive signaling regulator ABI5 was down-regulated and the negative regulator PP2C was up-regulated, thereby impairing ABA signal transduction. In addition, genes involved in salicylic acid (SA) biosynthesis and signaling (PAL, C4H, NPR4, WRKY45) were broadly down-regulated concurrently with reduced antioxidant enzyme activities. Furthermore, NpWRKY38 overexpression exacerbated drought-induced chloroplast damage, as evidenced by a greater reduction in SPAD values and severe chloroplast ultrastructural abnormalities, including swelling, disorganized thylakoid lamellae, and disrupted grana. These three pathways, namely impaired ABA/SA signaling, suppressed photosynthesis, and chloroplast damage, collectively exacerbated the drought-sensitive phenotype of the OE lines. This study demonstrates that NpWRKY38 acts as a multi-pathway negative regulatory mechanism by interfering with ABA signal transduction, suppressing the SA pathway, down-regulating photosynthetic genes, and compromising chloroplast integrity, providing a potential target for drought tolerance breeding in sugarcane.
Shuang-Cai Li, Hai-Bi Li, Kai Zhu et al.· Plants· 0 citations
Alfalfa, a globally important leguminous forage crop, is valued for high yield, superior nutritional quality, and robust stress resistance. It is widely used in animal husbandry and ecological protection. However, soil salinization has become a major environmental factor limiting its yield and quality. In this study, two alfalfa cultivars, Zhongmu No. 1 (ZM) and SK3010 (SK), were subjected to saline‐alkali stress. The treatment resulted in stunted growth, leaf chlorosis, and cell membrane damage. Compared with SK, ZM exhibited less damage and stronger saline‐alkali tolerance. Transcriptomic analysis revealed that the proportion of up‐regulated differentially expressed mRNAs (DEMs) in ZM was significantly higher than in SK. The antioxidant systems and plant hormone signal transduction pathways are central to saline‐alkali stress adaptation. Integrated transcriptome and small RNA sequencing identified 59 saline‐alkali stress‐responsive differentially expressed microRNAs (DEMIs) that target 119 DEMs. Functional analysis demonstrated that the phenylpropanoid biosynthesis and the starch and sucrose metabolism pathways are critical for stress response. These results indicated that alfalfa mitigates saline‐alkali stress through the regulation of the antioxidant system, hormone biosynthesis and signaling, phenylpropanoid biosynthesis, and the hydrolysis of starch to soluble sugars. In particular, ZM exhibited greater tolerance by accumulating fewer reactive oxygen species while elevating antioxidant enzyme activity and antioxidant content and enhancing lignin and sucrose biosynthesis. Furthermore, we constructed a miRNA‐mRNA regulatory network responsive to saline‐alkali stress, which included miR164 and miR172 family members targeting CSE (MsG0880047430.01) and TPS (MsG0880045029.01), respectively. This work offers valuable molecular resources for multi‐gene improvement of saline‐alkali tolerance in alfalfa.
Yu Zhang, Xiaoyu Zhang, Jieyun Cheng et al.· Physiologia Plantarum : An I...· 0 citations
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