Phenotypic, physiological and transcriptomic analysis of graded salt stress responses in Pyrus betulifolia Bunge and functional characterization of the hub gene PbSTY46.
Aug 2026· Plant Science· Vol 372, pp.
113390
· 0 citations· 46 references
Medicine
TL;DR
Findings establish PbSTY46 as a key regulator that links JA signaling to antioxidant defense to confer salt tolerance in P. betulifolia and represents a promising candidate for marker‑assisted breeding of salt‑tolerant pear cultivars.
Abstract
Pyrus betulifolia Bunge is a salt‑tolerant rootstock for pear, but its salt‑tolerance mechanisms remain largely unknown. In this study, P. betulifolia seedlings were subjected to graded NaCl stress at concentrations of 0 (CK), 50 (T1), 100 (T2), and 200 (T3) mM. We integrated phenotypic observation, physiological assessment, transcriptomic profiling, and functional gene validation to systematically elucidate its salt tolerance mechanisms. Salt stress inhibited seedling growth and root traits in a concentration-dependent manner, and T3 caused the most severe damage. Osmotic solutes responded differentially: soluble sugars peaked under T2, while proline peaked under T3. Antioxidant enzymes showed tissue-specific biphasic responses and declined after prolonged T3 stress. Meanwhile, chlorophyll and photosynthesis decreased, whereas anthocyanin increased, indicating a metabolic shift from photosynthesis to photoprotection. Transcriptome analysis revealed distinct responses depending on stress intensity: mild stress induced membrane lipid remodeling, moderate stress activated circadian rhythm and hormone signaling, and severe stress enhanced phenylpropanoid biosynthesis and thiamine metabolism. Gene Set Enrichment Analysis (GSEA) further highlighted progressive enrichment of phenylpropanoid biosynthesis, heme binding, and oxidoreductase activity. Weighted Gene Co‑expression Network Analysis (WGCNA) identified a blue module significantly positively correlated with root traits, from which the hub gene PbSTY46 was identified. Functional validation via overexpression, loss‑of‑function mutants, and pharmacological interventions (MeJA/DIECA) confirmed that PbSTY46 acts through JA signaling to enhance antioxidant enzyme activities and thereby confer salt tolerance. Collectively, P. betulifolia adopts a "survival‑first" strategy that coordinates growth arrest, osmotic homeostasis, and ROS scavenging. These findings establish PbSTY46 as a key regulator that links JA signaling to antioxidant defense. Thus, PbSTY46 represents a promising candidate for marker‑assisted breeding of salt‑tolerant pear cultivars.
This study provides a root-focused transcriptomic resource and identifies candidate regulatory genes potentially linking ABA-related responses with lignin/lignan-associated metabolism in H. pedunculosum under salt stress.
Yang Tao, Xiao Huang, Enhao Zhang et al.· Plant physiology and biochem...· 2 citations
Crop productivity around the world is largely constrained by salt-induced stress, a key abiotic factor. Although oat (Avena sativa L.) can withstand challenging environmental conditions, the physiological and molecular responses underlying salt tolerance during germination and early seedling development remain insufficiently understood. To investigate these responses, 28 oat varieties were evaluated at the germination stage, and two contrasting varieties, the salt-tolerant Mengshi No. 1 (MS) and salt-sensitive Morgan (MG), were selected for detailed analysis under a severe NaCl treatment (300 mM) during early seedling stages. Under severe salt stress, the two oat varieties exhibited distinct growth and physiological responses, including changes in growth traits, chlorophyll content, membrane stability, osmotic adjustment, and antioxidant responses. Transcriptomic analysis revealed 14,109 differentially expressed genes (DEGs) between salt-treated MG and its respective control (CK), 19,405 between salt-treated MS and its CK, and 6161 between salt-treated MG and salt-treated MS, suggesting different transcriptional response patterns between the salt-tolerant and salt-sensitive varieties under severe salt stress. Weighted gene co-expression network analysis (WGCNA) revealed a salt-responsive module associated with MS, from which five hub genes, AVESA.00010b.r2.1CG0087930 (MGL), AVESA.00010b.r2.19DG0180280 (MGL), AVESA.00010b.r2.4CG1272260 (BCH1), AVESA.00010b.r2.5DG0989800 (GPAT7), and AVESA.00010b.r2.6CG1124100 (TPR10), were identified as candidate genes potentially associated with salt tolerance and stress responses.
Rui Qiu, Xin-Yi Zhang, Xiang-Peng Kong et al.· Plants· 0 citations
Genotype- and tissue-specific flavonoid remodeling in C. rigescens under salt stress and overexpression of CrHPPD in Arabidopsis thaliana are revealed, suggesting two stress-responsive components of phenylalanine/tyrosine-derived metabolism, although their direct mechanistic connection requires further validation.
Yiming Wu, Jie Zhang, Qiannan Hu et al.· Journal of plant physiology· 0 citations
Soil salinization severely limits forage crop productivity, yet the regulatory networks that govern salt stress adaptation in alfalfa, a moderately salt-tolerant leguminous forage, remain largely unexplored. Here, we examined the physiological and transcriptomic dynamics of alfalfa leaves under 200 mM NaCl stress across three time points. Salt stress induced a progressive elevation of the Na+/K+ ratio, biphasic activation of antioxidant enzymes and concurrent accumulation of malondialdehyde. Time-course RNA-seq analysis identified 3631 differentially expressed genes (DEGs) and 132 core salt-responsive transcription factors (TFs). Pathway and functional annotation analyses indicated that these DEGs were prominently involved in cell wall biogenesis, redox homeostasis, and the carotenoid biosynthesis pathway, with carotenoid accumulation strongly activated under salt stress. Using weighted gene co-expression network analysis (WGCNA), nine distinct co-expression clusters were constructed. Notably, the brown module, which showed a positive correlation with Na+ accumulation and the Na+/K+ ratio, was significantly enriched in the plant hormone signal transduction pathway, within which 72.7% of the enriched genes belonged to the TIFY family. Among them, a core hub gene, MsTIFY11B, was isolated for functional characterization. Subcellular localization demonstrated that MsTIFY11B is exclusively localized to the nucleus. Heterologous expression in yeast showed that MsTIFY11B overexpression enhanced tolerance to salinity and alkalinity, whereas it conferred negligible protection against mannitol-induced drought stress. Taken together, our findings provide a comprehensive temporal framework of the alfalfa transcriptomic response to salinity and suggest that MsTIFY11B may contribute to salt–alkali tolerance, making it a promising candidate for further functional characterization and potential application in the development of stress-adapted alfalfa varieties.
Lin Cheng, Yan-Feng Liu, Qing-Chun Liu et al.· Plants· 0 citations
Tanacetum cinerariifolium (pyrethrum) is a commercially valuable ornamental and economically important industrial crop that produces pyrethrins, a mixture of six insecticidal esters with potent insecticidal activity and a relatively low toxicity to mammals. Drought stress is a major constraint on pyrethrum cultivation, impairing vegetative growth and leaf physiological function. However, the effects of drought on pyrethrin biosynthesis and the underlying drought-response mechanisms remain poorly understood. In this study, we investigated drought-induced changes in pyrethrum leaves through integrated phenotypic observation, physiological and biochemical analyses, and transcriptome sequencing. Drought stress caused leaf dehydration, wilting, and chlorosis, accompanied by increased activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), together with enhanced proline accumulation, indicating the activation of reactive oxygen species (ROS) scavenging and osmotic adjustment. Under severe drought stress, membrane lipid peroxidation increased further, indicating damage to cellular integrity. Transcriptomic analysis revealed extensive drought-induced transcriptional reprogramming in pyrethrum leaves, with the number of differentially expressed genes increasing as the stress severity increased. Abscisic acid (ABA) biosynthesis pathway was significantly activated, with 9-cis-epoxycarotenoid dioxygenase 3 (NCED3) strongly upregulated under severe drought stress, whereas NCED9 and abscisic aldehyde oxidase 3 (AAO3) were primarily responsive to mild drought stress and downregulated under severe conditions. Concurrently, the pyrethrin biosynthesis pathway was partially inhibited, indicating that pyrethrum prioritizes ABA-mediated drought tolerance over pyrethrin production. These findings provide insight into drought-induced physiological and transcriptional responses and may inform the development of drought-tolerant pyrethrum germplasm with an enhanced quality.
Wenqing Zhang, Da-Ju Chen, Xi-Yan Luo et al.· Horticulturae· 1 citation
Nelumbo nucifera Gaertn. is an economically and ecologically important aquatic plant, but its growth and productivity are severely constrained by soil salinization and alkalization. AP2/ERF transcription factors are key regulators of plant abiotic stress responses; however, their roles in salt–alkali tolerance in N. nucifera remain largely unclear. In this study, we performed a genome-wide identification and characterization of the AP2/ERF gene family in N. nucifera, followed by phylogenetic, structural, and physicochemical analyses. A total of 101 AP2/ERF genes were identified and classified into five subfamilies, showing both evolutionary conservation and species-specific divergence compared with Arabidopsis thaliana. Physiological analyses during seed germination under salt–alkali stress revealed significant changes in malondialdehyde content, proline accumulation, and antioxidant enzyme activities, suggesting activation of oxidative stress defense and osmotic adjustment mechanisms. Transcriptome profiling of seedlings treated with 150 mM salt–alkali solution for 5 and 10 days identified 7,350 differentially expressed genes, including 29 AP2/ERF members responsive to stress. Among them, 13 genes, including AP2-9, ERF23, ERF15, ERF31, ERF34, and DREB21, were consistently upregulated under both treatments, indicating their potential roles in stress adaptation. qRT-PCR validation further confirmed the sustained upregulation of key genes AP2-9, ERF23, ERF34, and DREB21, consistent with transcriptome data. Overall, this study provides the first comprehensive overview of the AP2/ERF gene family in N. nucifera and identifies candidate regulators involved in salt–alkali stress responses, offering valuable insights into the molecular mechanisms of stress adaptation and potential genetic resources for breeding salt–alkali tolerant aquatic plants.
Rong-Qing Wang, Pei-Ying Liu, Shuai Li et al.· Frontiers in Plant Science· 0 citations
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