Search Results (1,638)

This study comprehensively characterizes the PEBP gene family in Cymbidium sinense, an orchid with a prolonged vegetative phase that limits its industrial production. Genome-wide analysis identified six CsPEBPs, classified into FT-like, TFL1-like, and MFT-like subfamilies. Evolutionary, gene structure, and collinearity analyses revealed both conservation and lineage-specific diversification of these genes. CsFTL3, a distinctive FT-like member, displayed notably high expression during the bud undifferentiated stage, followed by a sharp downregulation upon floral initiation. Functional studies identified CsFTL3 as a key floral repressor. Heterologous overexpression in Arabidopsis delayed flowering time from 32.0 days (wild-type) to 63.0–75.3 days (transgenic) and increased rosette leaf number from 12.6 to 33.0–34.5, while its knockdown via virus-induced gene silencing (VIGS) in C. sinense accelerated floral bud development and upregulated flowering-promoter genes. Phylogenetically, CsFTL3 falls within the flowering repressor FT-I clade, and multiple sequence alignment identified critical amino acid substitutions (Y134S, W138L, Q140E) that likely underpin its functional divergence from typical flowering promoters. Furthermore, promoter analysis revealed an enrichment of light-, hormone-, and stress-responsive cis-elements, and its expression was modulated by gibberellin (GA), abscisic acid (ABA), and low-temperature treatments. Predicted protein–protein interaction and transcriptional regulatory networks provide preliminary insights into its complex regulation. We conclude that CsFTL3 acts as a crucial floral inhibitor, integrating environmental and endogenous cues to repress flowering. These findings offer fundamental insights into the molecular mechanisms of flowering in orchids and provide a valuable genetic resource for molecular breeding programs aimed at achieving precise flowering time control. Full article

Heat shock transcription factors (HSFs) play a central role in mediating plant responses to abiotic stress. Anthocyanins, one of the most important secondary metabolites in plants, contribute to both stress tolerance and the enhancement in crop nutritional quality. However, the possible role of HSFs in regulating anthocyanin biosynthesis in sweet potato (Ipomoea batatas L.) remains unknown. This study conducted a genome-wide analysis of the sweet potato HSF gene family to explore their functions related to anthocyanin metabolism and salinity stress. Multiple stress-inducible promoter elements were identified within IbHSF22, including those induced by drought, salt, heat, ABA, and light. For functional characterization of this gene, a 35S-driven overexpression construct was prepared and then transformed into Nicotiana benthamiana. Overexpression of IbHSF22 led to a nearly two-fold increase in anthocyanin content, concurrently with the elevated expression of key structural genes such as NtCHS, NtF3H, NtDFR, and NtANS. Under salt stress, the transgenic plants also exhibited enhanced tolerance, which was associated with maintained antioxidant enzyme activity and concerted induction of stress-responsive genes, events that collectively resulted in decreased oxidative damage. Therefore, the present work identifies IbHSF22 as an integrator of anthocyanin biosynthesis and salt defense mechanisms. These findings provide a conceptual basis and candidate gene strategy for dual improvement in stress resilience and nutritional quality in sweet potato breeding. Full article

Potato is a globally important non-cereal crop in which infection with potato spindle tuber viroid (PSTVd) can cause stunted growth and significantly reduce tuber yield. We previously showed that PSTVd induces accumulation of the plant hormone jasmonic acid (JA) and alters antioxidant responses in potato plants. To clarify the role of JA in response to PSTVd, we analyzed disease development in transgenic JA-deficient opr3 and JA-insensitive coi1 lines compared to the wild-type. Transcriptomic analysis using RNA-Seq revealed that most genotype-specific differentially expressed genes (DEGs) in all comparisons were enriched in plant hormone signal transduction, plant-pathogen interaction, and MAPK signaling pathways, although the number of DEGs varied. These differences were confirmed by independent data from RT-qPCR, hormone, and hydrogen peroxide (H₂O₂) analyses. After PSTVd infection, opr3 plants showed enhanced JA signaling and increased abscisic acid (ABA) and auxin (AUX) content. In contrast, coi1 plants showed reduced ABA, AUX, and salicylic acid content. Both opr3 and coi1 plants showed reduced JA and H₂O₂ content and lower expression of defense-related genes, resulting in milder symptoms but increased viroid accumulation. In addition, treatment with methyl jasmonate alleviated symptoms in infected wild-type plants. Together, these results indicate a modulatory role for JA and JA signaling in basal immune responses and symptom development in the potato-PSTVd interaction. Full article

Rice (Oryza sativa L.) is a major global staple crop, yet its productivity is severely constrained by rice blast disease caused by Magnaporthe oryzae. FK506-binding proteins (FKBPs) are peptidyl-prolyl cis-trans isomerases involved in protein folding, stress response, and signaling regulation, but their roles in rice blast resistance remain unclear. In this study, we performed a comprehensive identification and characterization of FKBP gene family members in two rice cultivars, Nipponbare (NIP) and Zhonghua 11 (ZH11), based on the latest T2T (telomere-to-telomere) genome assembly of ZH11 and the reference genome of NIP. A total of 24 and 29 FKBP genes were detected in NIP and ZH11, respectively, indicating a slight expansion in ZH11. Phylogenetic and collinearity analyses revealed strong conservation of FKBP family members between the two cultivars, while several ZH11-specific genes likely resulted from recent duplication events. Promoter analysis showed that FKBP genes are enriched in stress and hormone responsive cis-elements, particularly those related to ABA, MeJA, and SA signaling. Transcriptomic and RT-qPCR analyses demonstrated that multiple FKBP genes were significantly regulated during M. oryzae infection, suggesting their potential involvement in defense signaling pathways. This study provides a comprehensive overview of FKBP gene family evolution and expression in rice, identifies candidate genes potentially associated with blast resistance, and offers valuable insights for molecular breeding aimed at improving disease resistance in rice. Full article

Kiwifruit (Actinidia deliciosa) contributes >4 million tons to global fruit production annually and ranks among the highest dietary sources of vitamin C and bioactive polyphenols. Its quality is mainly influenced by the coordinated regulation of essential metabolites during fruit ripening. Although several important metabolites associated with fruit color, flavor, and nutrition have been elucidated, the dynamic changes and regulatory networks of ripening-associated metabolites remain largely unexplored. In this study, comprehensive metabolic dynamics of developing fruit of Actinidia deliciosa cv. Xuxiang (‘XX’) were investigated through a widely targeted metabolomic analysis. Three metabolites associated with hormone metabolism showed that differentially accumulated 12-oxo-phytodienoic acid (12-OPDA) and jasmonic acid (JA) were downregulated, while abscisic acid (ABA) was upregulated in XX9 vs. XX21, with a Log₂|fold change| of −1.96, −3.09, and 1.76, respectively. Two hub genes (AdOPR3 and AdCYP707A4) were then screened based on integrative analyses of metabolome and transcriptome data, and showed significantly decreased expression during ‘XX’ fruit ripening, which might be responsible for the reduced content of JA and enhanced level of ABA, respectively. Furthermore, co-expression networks of AdOPR3 and AdCYP707A4 were constructed by WGCNA and the potential transcriptional regulators of these two hub genes were predicted based on a correlation threshold over 0.9. Taken together, these results revealed the opposing accumulation patterns of JA and ABA might contribute to physiological ripening in kiwifruit, via the TF-mediated transcriptional regulation of AdOPR3 and AdCYP707A4. These findings provide insights for hormonal control of fruit ripening. Full article

BTB-TAZ (BT) proteins are plant-specific transcription factors that contain a BTB domain and a TAZ domain and play vital roles in various biological processes, growth regulation, and stress responses. In this study, we investigate the effect of overexpressing the cucumber CsBT1 gene in Arabidopsis thaliana on its tolerance to salt and drought. Quantitative analysis revealed significant downregulation of CsBT1 under salt and drought treatments, contrasting with its ABA-induced expression. The CsBT1 gene was introduced into Arabidopsis under the control of 35S promoter via floral dip transformation method. Two CsBT1-overexpressing transgenic Arabidopsis lines were used for stress treatment and phenotypic studies. The transgenic lines exhibited reduced germination, shorter root lengths, and accelerated leaf chlorosis under salt and drought treatments, in comparison to wild-type (WT) plants. Furthermore, overexpressed lines accumulated higher reactive oxygen species with lower superoxide dismutase (SOD) activity, correlating with increased electrolyte leakage and malondialdehyde (MDA) content. Notably, abscisic acid (ABA) treatment rescued the root growth inhibition in CsBT1-overexpressing transgenic Arabidopsis lines. Taken together, these results establish CsBT1 as a key negative regulator of salt and drought tolerance that functions through the ABA signaling pathway. Full article

Drought severely limits plant growth, threatening global food security and biodiversity. This review provides a comprehensive overview of the recent advances in plant responses to drought, ranging from initial sensing to physiological adaptation, as well as guidelines for experimental design. We focus on key regulatory components, specifically the ABA signaling core (PYR/PYL/RCARs, PP2C phosphatases, and SnRK2 kinases) and ROS signaling. We provide a detailed description of transcriptional networks, highlighting the pivotal roles of DREB, NAC, and MYB transcription factors in coordinating gene expression. Furthermore, we explore downstream tolerance strategies, including osmoprotectant (e.g., proline) accumulation, cell wall remodeling involving expansins and pectin methylesterases, as well as stomatal regulation. We also discuss how combining genetics with multi-omics and high-throughput phenotyping bridges the gap between molecular mechanisms and whole-plant physiological performance. Ultimately, these insights provide a foundation for refining research approaches and accelerating the development of drought-resilient crops to sustain agricultural productivity and ecosystem stability in increasingly arid environments. Full article

Waterlogging is a major abiotic stress that restricts plant growth, productivity, and survival by disrupting root aeration and altering hormonal homeostasis. To elucidate the physiological and molecular responses associated with flooding tolerance in Liriodendron hybrids (Liriodendron chinense × Liriodendron tulipifera), this study investigated its morphological, physiological, and transcriptomic changes under 0, 1, 3, and 6 days of waterlogging. Roots exhibited rapid decay, while leaves showed delayed chlorosis and reduced chlorophyll content. Changes in antioxidant enzyme activities reflected enhanced antioxidant capacity, with superoxide dismutase (SOD) activity decreasing and peroxidase (POD) and catalase (CAT) activities increasing. Hormone measurements indicated organ-specific patterns, including abscisic acid (ABA) accumulation in leaves and decreased indole-3-acetic acid (IAA) and gibberellin (GA) levels in both roots and leaves. Transcriptome profiling revealed extensive transcriptional adjustments in hormone biosynthesis, signaling, and stress-responsive pathways, including divergent regulation of ABA-associated genes in leaves and roots and broad downregulation of auxin- and gibberellin-related genes. Key ABA biosynthetic genes (NCED1, ABA2) and signaling components (PYL4, PP2C, ABF) were upregulated in leaves but downregulated in roots, whereas auxin (YUC6) and gibberellin (GA20ox) genes were generally suppressed. These coordinated physiological and molecular responses suggest organ-differentiated adaptation to waterlogging in Liriodendron hybrids, highlighting candidate pathways and genes for further investigation and providing insights for improving flooding tolerance in woody species. Full article

The stress-associated proteins (SAPs) correspond to zinc-finger proteins containing A20/AN1 domains that are involved in plant responses to a wide range of biotic and abiotic stresses. However, in oat, no information has been available so far regarding the characteristics and regulation of these genes. In the current research work, eleven AvSAP genes were identified in oats genome (OT3098 variety) named AvSAP1 to AvSAP11. Eight proteins contained both A20 and AN1 domains located at the N- and C-terminal portions of the proteins, respectively. Subsequently, the gene structure and duplication, chromosomal location, cis-acting elements, and protein properties were analyzed using bioinformatic tools. Moreover, genes expression profiles revealed that AvSAP genes present hormones and stress-responsive cis-elements in their promoters. These observations were confirmed using QRT-PCR analysis. Indeed, the majority of identified AvSAP genes were responsive to NaCl, PEG, heat, ethylene, and metallic (Mn, Cu, and Cd) stresses. Moreover, ABA phytohormone induced a significant upregulation of nine AvSAP genes in leaves (5.8–6.5-fold induction) and roots (1.9–4.2-fold induction), corroborating their crucial role of those genes in plants’ response to a wide range of abiotic stresses. In contrast, GA and IAA exert a slight effect on those genes. Finally, AvSAP1 protein expression in bacterial cells conferred tolerance to ionic and osmotic stress. Our results provide deeper insight into AvSAP genes in plants and support advanced functional analyses of this gene family in oats. Full article

The cation/H⁺ exchanger (CHX) gene family plays a vital role in maintaining K⁺/Na⁺ homeostasis in plants, yet its functional characterization in pepper (Capsicum annuum L.) remains largely unexplored. To elucidate the potential roles of CHX genes in stress adaptation and development in pepper, a genome-wide identification and systematic analysis of this gene family was performed. Using a combination of Hidden Markov Model (HMM) searches, phylogenetic reconstruction, conserved motif and promoter analysis, and expression profiling across tissues and under multiple stress conditions, a total of 23 CaCHX genes were identified, which are unevenly distributed across 10 chromosomes and classified into 6 phylogenetic subfamilies. Expression profiling revealed that most CaCHX genes were highly expressed in flowers, suggesting their potential involvement in reproductive development, while only CaCHX12 and CaCHX17 were detected in leaves. Under treatments such as abscisic acid (ABA), gibberellic acid (GA), NaCl, and jasmonic acid (JA), CaCHX1, CaCHX20, and CaCHX23 exhibited distinct temporal expression patterns, suggesting their involvement in hormone-mediated stress responses. This study provides the first comprehensive genomic and transcriptomic overview of the CHX family in pepper, offering novel insights into its regulatory roles in flower development and stress tolerance and, thus supplying valuable genetic resources for molecular breeding aimed at enhancing pepper resilience. Full article

MicroRNAs (miRNAs) act as pivotal post-transcriptional regulators of gene expression in plant stress responses. However, the transcriptional regulation mechanisms governing miRNA genes themselves remain insufficiently characterized. This study focuses on Eca-miR482f, a previously identified cold-responsive miRNA from Eucalyptus camaldulensis that targets EcaSIZ1—a key component of the ICE1–CBFs–CORs cold signaling pathway. We first investigated the expression pattern of Eca-miR482f and found it exhibited root-preferential accumulation in E. camaldulensis. Under cold stress, it displayed divergent organ-specific responses: strong induction in roots and suppression in aerial tissues. To elucidate its transcriptional regulation, we cloned a 1938 bp promoter sequence upstream of the Eca-miR482f precursor. Bioinformatics analysis revealed that this promoter was highly conserved within the Eucalyptus genus and enriched with multiple cis-acting elements associated with stress responses—including a low-temperature-responsive element (LTR)—as well as hormone signaling, such as abscisic acid (ABA) and methyl jasmonate (MeJA)-responsive motifs. A series of 5′-deletion fragments were generated to delineate the functional regions within the promoter. Through transgenic approaches in both tobacco and Arabidopsis, we demonstrated that this promoter drove strong, root-preferential expression. Furthermore, it exhibited significant inducibility under cold and MeJA treatments. Systematic truncation analysis delineated specific promoter regions essential for maintaining this organ specificity and stress responsiveness, thus identifying potential functional modules. Briefly, our findings provide crucial insights into the transcriptional regulation of Eca-miR482f and uncover a valuable genetic tool for future biotechnological engineering of stress-tolerant woody plants via precise spatiotemporal modulation of gene expression. Full article

Salinity is among the main abiotic constraints limiting crop productivity worldwide. Salt tolerance can be improved by introducing adaptive traits from wild species and enhancing pre-existing salt-adaptive mechanisms through priming. This study evaluated the beneficial effect of salicylic acid (SA, 1.25 mM) and calcium chloride (CaCl₂, 5 mM) seed priming on plant growth under salinity in the domestic barley Hordeum vulgare (Hv) and the wild, salt-adapted Hordeum maritimum (Hm). Primed plants were grown under control, 100 and 200 mM sodium chloride (NaCl) for two weeks. Growth and hormone profiling were performed. Hv showed higher growth inhibition than Hm but was more responsive to stress alleviation by priming, particularly with SA, which increased biomass by up to 47% at 200 mM NaCl. The contrasting responses of both species reflected distinct hormonal strategies. The intrinsic salt tolerance of Hm appears linked to high constitutive levels of stress- and growth-related hormones. In Hv, growth recovery under salinity following priming was associated with hormonal reprogramming, involving reduced abscisic acid (ABA) accumulation and enhanced levels of growth-promoting hormones (indole-3-acetic acid (IAA), trans-zeatin (tZ), and isopentenyl adenine (iP)), especially in roots. Hormonal changes mediated by priming are analyzed in relation to adaptive growth responses and species’ ecological origins. Full article

Protein post-translational modifications (PTMs), as an important biological process of plants responding to environmental stimuli, can regulate the chemical decoration and properties of translated proteins by altering amino acid side chains or protein terminal structures, thereby affecting the synthesis, assembly, localization, function, and degradation of proteins. Notably, PTMs regulate protein function without changing protein expression levels. Two dozen types of PTMs have been identified. This review summarizes the molecular mechanisms of major types of PTMs, including phosphorylation, ubiquitination, SUMOylation, glycosylation, methylation, and acetylation, with a focus on their regulatory roles in plant responses to abiotic stresses. Under heat stress, phosphorylation activates transcription factors such as HSFA1 (heat shock transcription factor 1), while SUMOylation regulates the activity of HSFA1/HSFA2 in the heat stress signaling pathway. Upon cold stress, phosphorylation, ubiquitination, and S-acylation collectively regulate the expression of cold tolerance-related genes. The drought stress response relies on SnRK2s (Sucrose 321 non-Fermenting 1-related protein kinase 2s) -mediated phosphorylation, regulation of ARF7 (auxin response factor 7) by SUMOylation, and ubiquitination. In salt stress, the coupling of phosphorylation of SOS (salt overly sensitive) pathway-related proteins, ubiquitination, and phospholipid metabolism maintains ion homeostasis. Additionally, PTMs play a key role in ABA-mediated abiotic stress responses by regulating core components of signal transduction, such as PYR (pyrabactin resistance)/PYL (PYR1-LIKE)/RCAR (regulatory components of ABA receptor) receptors, PP2Cs (protein phosphatases type 2C), and SnRK2s. On the basis of the synthesis of the regulatory mechanisms of PTMs, we discuss how PTMs can be manipulated to breed abiotic stress resilient crops and the issues to be addressed to achieve the goal, such as crosstalk between PTMs, technical challenges in investigating PTMs and identifying PTM substrates. Full article

Salt stress represents a significant abiotic factor that constrains maize growth. Epigenetic modifications play a crucial role in enabling plants to respond effectively to such stresses. Among these alterations, m⁶A methylation, which is the most common post-transcriptional modification of eukaryotic mRNA, shows dynamic variations that are closely linked to stress responses. In this study, we conducted a transcriptome-wide m⁶A methylation analysis on maize roots from the inbred line PH4CV, following treatment with 180 mM NaCl. The results identified 1309 differentially m⁶A methylated peaks (DMPs) and 2761 differentially expressed genes (DEGs) under salt stress conditions. Association analysis revealed that 179 DEGs contain DMPs. Key pathways involved in stress responses, including Ca²⁺ signaling transduction and ABA signaling, as well as ion homeostasis regulation (involving AKT, HKT, and other families) and the reactive oxygen species scavenging system (including POD, SOD, and CAT), play crucial roles in coping with salt stress. Furthermore, we identified a total of 26 m⁶A-related genes, comprising 7 eraser genes, 10 reader genes, and 9 writer genes. Notably, several key salt-responsive genes, such as RBOHB, AKT1, HKT1, and POD12, are correlated with m⁶A modification. This study provides a comprehensive map of m⁶A methylation dynamics in maize roots under salt stress, laying a foundational resource for future investigations into the epigenetic regulation of salt tolerance in maize. Full article

Protein phosphatase 2Cs (PP2Cs) constitute a widespread family of signaling regulators in plants and play central roles in abscisic acid (ABA)-mediated stress signaling; however, the PP2C gene family has not yet been systematically identified and characterized in pea (Pisum sativum), a salt-sensitive legume crop. In this study, we identified 89 PsPP2C genes based on domain features and sequence homology. These genes are unevenly distributed across seven chromosomes and classified into ten subfamilies, providing a comparative framework for evaluating structural and regulatory diversification within the PsPP2C family. The encoded proteins vary substantially in length, physicochemical properties, and predicted subcellular localization, while most members contain the conserved PP2Cc catalytic domain. Intra- and interspecies homology analyses identified 19 duplicated gene pairs in pea and numerous orthologous relationships with several model plants; all reliable gene pairs exhibited Ka/Ks < 1, indicating pervasive purifying selection. PsPP2C genes also showed broad variation in exon number and intron phase, and their promoter regions contained diverse light-, hormone-, and stress-related cis-elements with heterogeneous positional patterns. Expression profiling across 11 tissues revealed pronounced tissue-specific differences, with generally higher transcript abundance in roots and seeds than in other tissues. Under salt treatment, approximately 20% of PsPP2C genes displayed concentration- or time-dependent transcriptional changes. Among them, PsPP2C67 and PsPP2C82—both belonging to the clade A PP2C subfamily—exhibited the most pronounced induction under high salinity and at early stress stages. Functional annotation indicated that these two genes are involved in ABA-related processes, including regulation of abscisic acid-activated signaling pathway, plant hormone signal transduction, and MAPK signaling pathway-plant. Collectively, this study provides a systematic characterization of the PsPP2C gene family, including its structural features, evolutionary patterns, and transcriptional responses to salt stress, thereby establishing a foundation for future functional investigations. Full article