Search Results (1,692)

The Dof transcription factor family plays crucial roles in plant growth and stress responses. In this study, we identified 24 Dof genes (CcDof1–CcDof24) from the genome of Citrus clementina (Hort. ex Tan.). Phylogenetic analysis classified these proteins into six distinct clades, revealing evolutionary conservation with Dof members from Arabidopsis and tomato. Analysis of gene structure and conserved motifs showed that most CcDof genes are intronless or contain only a few introns, and their motif compositions are largely consistent with their phylogenetic relationships. Promoter analysis revealed a variety of cis-regulatory elements associated with light responsiveness, hormone signaling, and abiotic/biotic stress responses. Expression profiling demonstrated that CcDof genes exhibit tissue-specific expression patterns and are differentially regulated by various phytohormones (including ABA, SA, GA, and MeJA), low temperature stress, and infection by Phytophthora parasitica. Notably, transient overexpression of CcDof4 and CcDof6 in citrus leaves significantly enhanced resistance to P. parasitica, accompanied by upregulation of SA pathway markers NPR1 and PR1. Our findings provide a systematic characterization of the CcDof family and highlight the important roles of CcDof4 and CcDof6 in mediating citrus disease resistance, likely through modulation of the SA signaling pathway. Full article

The ZF-HD transcription factors play key roles in plant development and stress responses, yet their functions in cucumber remain poorly understood. Here, we characterized a cucumber ZF-HD gene, CsHB33, and investigated its role in leaf development and drought tolerance. CsHB33 was highly expressed in developing leaves. Its expression was significantly suppressed by abscisic acid (ABA) and down-regulated under drought stress. Heterologous overexpression of CsHB33 in Arabidopsis promoted leaf growth by increasing cell size, but simultaneously enhanced sensitivity to osmotic and drought stress, accompanied by higher stomatal aperture and water loss. Transcriptomic analysis revealed that CsHB33 overexpression up-regulated genes associated with leaf enlargement, while under drought it led to constitutive activation of aromatic amino acid biosynthesis, particularly tryptophan metabolism. This metabolic disturbance likely contributes to the drought-sensitive phenotype. Our findings reveal that CsHB33 exerts opposing effects on leaf growth and drought tolerance, providing new insights into ZF-HD gene function in cucumber and identifying a potential target for improving stress resilience in breeding. Full article

Heat stress, intensified by global warming, poses a great threat to plant growth and crop production. However, the molecular mechanisms underlying heat stress response (HSR) remain largely unclear. In this study, we identified and characterized SlFBX38, an F-box gene in tomato. SlFBX38 was predominantly expressed in leaves and fruits, and its expression levels were induced by heat stress and various phytohormones, including ABA, JA and SA. Subcellular location analysis revealed that SlFBX38 resides in both the nucleus and cytoplasm in N. benthamiana leaf cells, but it displays no transcriptional activity. Overexpression of SlFBX38 (OE) lines conferred enhanced heat stress tolerance, as evidenced by improved photosynthetic efficiency, elevated accumulation of ascorbic acid (AsA), stronger protective enzyme activities, and upregulation of HSR-related genes in SlFBX38-OE lines under heat stress condition. To identify potential interacting proteins, yeast two-hybrid (Y2H) library screening and further Y2H verification indicate that SlFBX38 may interact with SlbHLH058. Collectively, these findings establish SlFBX38 as a positive regulator of thermotolerance in tomato and provide a basis for further mechanistic studies of its role in HSR. Full article

Premature leaf senescence is a major constraint on rice (Oryza sativa L.) productivity and yield stability, particularly under increasingly frequent environmental stresses. Unlike developmentally programmed senescence, premature senescence is characterized by early and uncontrolled activation of senescence pathways, leading to accelerated chlorophyll degradation, oxidative damage, impaired photosynthesis, and reduced grain filling. Recent studies have revealed that premature senescence in rice is governed by a complex regulatory network integrating reactive oxygen species (ROS) homeostasis, phytohormone signaling, transcriptional regulation, and environmental cues. Central signaling hubs involving abscisic acid, ethylene, jasmonic acid, cytokinins, and gibberellins interact extensively with ROS metabolism to fine-tune senescence onset and progression. These upstream signals converge on key transcription factor families, particularly NAC and WRKY proteins, which directly regulate senescence-associated genes responsible for chloroplast dismantling, nutrient remobilization, and programmed cell death. Moreover, abiotic stresses such as drought, salinity, temperature extremes, and nitrogen deficiency commonly trigger premature senescence through a shared ABA–ROS signaling module. This review systematically summarizes recent advances in the physiological characteristics, molecular mechanisms, and environmental regulation of premature leaf senescence in rice, and discusses emerging genetic and agronomic strategies to delay senescence. A deeper understanding of senescence regulatory networks will facilitate the development of rice cultivars with prolonged photosynthetic duration, improved stress resilience, and enhanced yield stability under changing climatic conditions. Full article

Climate change-driven abiotic stresses threaten global potato production, yet stress-specific adaptive mechanisms remain poorly defined. We demonstrate that heat, drought and salt stresses induce fundamentally distinct physiological and biochemical responses in potato plants. Photosynthetic performance and gas exchange showed stress-specific patterns, with heat stress (HS) maintaining elevated carbon metabolism, drought stress (DS) causing severe photosynthetic suppression and water deficit, while salt stress (SS) exhibited intermediate physiological impairment. Secondary metabolite (SM) profiling revealed a corresponding stress-specific signature, where sesquiterpenes (caryophyllene, copaene, humulene) were dramatically elevated under HS but suppressed under DS (which specifically enhanced 1-hexanol and trans-sesquisabinene hydrate), while SS induced copaene and cis-β-farnesene but reduced caryophyllene. Phytohormone analysis demonstrated differential accumulation patterns across stresses: JA, JA-Ile, SA and ABA were maximally elevated under HS, moderately increased under DS, while SS uniquely maintained basal JA/JA-Ile with enhanced SA and ABA. Pharmacological intervention using hormone biosynthesis inhibitors (DIECA, SHAM, Jarin-1, AIP, ABT, fluridone) and exogenous ABA confirmed stress-specific regulatory networks. These findings establish a stress-specific hormone–metabolite regulatory framework, providing a molecular basis for developing climate-resilient potato genotypes. Full article

Silicon (Si) serves as a beneficial element that enhances plant resistance to both abiotic and biotic stresses. Although its positive effects have been widely investigated, the molecular mechanisms by which silicon improves stress tolerance in rice (Oryza sativa L.) remain unclear. Here, we show that Si displayed an optimal improved effect at concentrations of 2–4 mM in hydroponic system, and Si enhanced rice tolerance to drought and blast disease by maintaining reactive oxygen species (ROS) homeostasis and reducing root cell damage. In addition, Si at 4 mM upregulated the ABA biosynthesis gene OsNCED3, stress- and ABA-responsive genes OsDREB2A and OsLEA5, as well as the catalase gene OsCatB, while suppressing the drought-responsive negative regulator OsWRKY5, thereby enhancing drought tolerance through an ABA-dependent signaling pathway. Si at 4 mM enhanced resistance to rice blast by activating defense-related genes OsPBZ1, OsPR10a, OsPR5 and OsWRKY45 while simultaneously boosting ROS-scavenging capacity. Collectively, our results demonstrate that Si enhances rice tolerance to drought and blast disease through the coordinated modulation of ABA signaling, ROS homeostasis, and stress-related gene expression. Full article

Background: LATERAL ORGAN BOUNDARIES DOMAIN (LBD/AS2) transcription factors integrate developmental and hormonal signals during organogenesis. As a high-value fruit tree crop, blueberries’ rooting ability underpins their vegetative propagation and field performance, yet a genome-wide view of the LBD repertoire and its roles in blueberry has been lacking. Results: We cataloged 153 non-redundant LBD genes (VcLBD) by homology search against the GDV RefTrans V1 genome and domain validation, substantially exceeding counts reported for other fruit crops. Phylogeny resolved the family into the canonical Class I/II and seven subclades, with extensive lineage-specific expansion supported by synteny: 72.31% of loci arose from whole-genome/segmental and tandem duplication. Gene structures were highly heterogeneous (2–24 exons) but conserved within clades; motif profiling (MEME/InterPro) recovered the signature LOB cysteine block, GAS module and a leucine-zipper-like motif with clade-specific combinations. Promoter scanning identified 38 cis-element types, including hormone- (auxin, cytokinin, GA, JA/MeJA, ABA, SA), stress- and meristem-associated motifs, indicating broad regulatory inputs. Public transcriptomes revealed pronounced tissue–stage specificity with a root-centered bias; qRT-PCR across eight organs/stages validated four archetypal expression programs (higher expression in roots, flowers, fruits in stage 1, or mature fruit, respectively), including floral/early-fruit enrichment (e.g., VcLBD39/40) and ripening-associated induction. Hormone assays demonstrated differential responsiveness: IAA up-regulated VcLBD6/16b/33c/40e/41, whereas 6-BA suppressed VcLBD16b/33c/39a/39c/40e and induced VcLBD41/46h; ACC and MeJA produced gene-specific induction or repression. During adventitious rooting (0/4/7/10 DAC), 30 VcLBDs were differentially expressed, forming three temporal patterns. VcLBD16b reaches its peak expression during the early stages of adventitious root development and exhibits a strong response to auxin. VcLBD11 shows dynamic changes synchronized with cytokinin activity, while VcLBD33/40 is associated with primordia growth and vascular-related processes. Conclusions: We identified and characterized 153 VcLBD genes, profiled their transcripts across multiple blueberry tissues, defined stages of adventitious root development, and evaluated hormone responsiveness for representative members. Together, these results establish a foundation for dissecting VcLBD regulatory mechanisms and functions, particularly in organ growth and adventitious rooting. Full article

To decipher the molecular response mechanism of melon to saline–alkaline stress, seedlings of the melon cultivar “Xikaixin” were treated with 50 mmol·L⁻¹ mixed solutions of NaCl and NaHCO₃ at ratios of 1:1, 1:2, and 2:1 to simulate saline–alkaline stress. Transcriptome sequencing of roots (four biological replicates per group, with each replicate consisting of one pot containing four robust seedlings as the experimental unit) yielded 78.98 Gb of clean data (≥6.02 Gb per sample) with Q30 ≥ 96.61% and genome alignment rates of 97.00–98.02%, identifying 588, 686, and 1107 differentially expressed genes (DEGs) in the 1:1, 1:2, and 2:1 groups, respectively. Notably, the 1:1 treatment—mimicking the natural NaCl:NaHCO₃ ratio of saline–alkaline soil in southern Xinjiang—had 588 DEGs with the plant hormone signal transduction pathway as its most significantly enriched pathway, representing the core molecular response of “Xikaixin” to near-natural saline–alkaline stress. DEGs were significantly enriched in 50 pathways categorized into five major classes, with the plant hormone signal transduction pathway showing the highest enrichment across all treatments. A key observation from gene expression patterns is a potential auxin–ABA balance modulation, inferred from the differential expression of annotation-based auxin-related and ABA-related genes/pathways (no direct measurement of hormone levels or signaling was performed): two auxin-related genes (auxin-induced protein gene MELO3C013403 and auxin response factor gene MELO3C004381) were specifically upregulated (≥two fold vs. control) in the high-salt 2:1 group, while ABA-related genes were upregulated and auxin/jasmonic acid/gibberellin-related genes were downregulated in the 1:2 group, indicating a putative cultivar-specific hormone-related gene expression pattern associated with auxin–ABA crosstalk in “Xikaixin” under saline–alkaline stress. In contrast, photosynthesis-antenna protein genes (e.g., MELO3C021567) were significantly downregulated (to 32% of the control) under the 2:1 treatment. RT-qPCR validation confirmed the consistency of these candidate genes’ expression with transcriptomic data. Therefore, melon may respond to saline–alkaline stress by regulating the plant hormone signal transduction (especially auxin–ABA balance), photosynthesis, and carbon metabolism pathways. This study provides novel candidate genes and a theoretical basis for the genetic improvement of saline–alkaline-tolerant melon cultivars, with the unique auxin–ABA balance modulation as a key original contribution. Full article

Low-temperature stress during germination is a major constraint for lettuce establishment in temperate and early-season production systems, causing delayed emergence, poor stand uniformity, and reduced yield. Cold germination represents an adaptive trait that enables seeds to initiate growth under suboptimal temperatures, but its genetic basis in lettuce remains poorly understood. Here, we investigated genetic architecture underlying cold germination using a biparental recombinant inbred line population derived from a cross between Lactuca sativa cv. Salinas and Lactuca serriola (wild lettuce). Phenotypic evaluations revealed substantial variation in germination performance at low temperatures, with cultivated lettuce exhibiting superior cold germination compared with the wild parent. Estimates of heritability indicated that genetic factors accounted for a large proportion of the observed phenotypic variation, demonstrating strong potential for selection. Quantitative trait locus (QTL) analysis identified two genomic regions significantly associated with cold germination ability, together explaining a substantial fraction of phenotypic variance (35%). These regions contained candidate genes involved in hormone signaling, membrane stability, and stress-responsive transcriptional regulation, including components of abscisic acid (ABA), gibberellic acid (GA), and ethylene pathways known to modulate germination under adverse conditions. Together, these results indicate that cold germination is a genetically complex trait that has likely been shaped through domestication and breeding. By elucidating the genetic basis of cold germination in lettuce, this study provides valuable targets for marker-assisted breeding aimed at improving seedling establishment and extending lettuce production into cooler environments. Full article

Membrane lipid remodeling plays a pivotal role in regulating plant growth, reproductive development, and adaptive responses to environmental stress. However, several lipid-modifying enzymes remain uncharacterized in Arabidopsis thaliana. Here, we provide the first comprehensive in silico functional characterization of the unannotated gene AT5G35460, integrating domain architecture, AlphaFold-supported structural validation, and phylogenetic, expression, and regulatory analyses. Domain architecture and conserved DUF2838 signatures, together with transmembrane topology and validation using AlphaFold-predicted structural data, support its identity as a glycerophosphocholine acyltransferase (GPCAT1). Phylogenetic reconstruction showed that GPCAT1 clustered closely with its orthologs of major angiosperms, suggesting deep evolutionary preservation. Expression profiling revealed over a tenfold higher transcript abundance in mature pollen, detected 6–8 times more than during leaf senescence, indicating strong developmental control. Co-expression network analysis revealed links to the lipid metabolism genes (CDS2, LACS8, and SBH1) as well as factors involved in response to stress, indicating that AT5G35460 may act at the level of phosphatidylcholine remodeling, membrane resistance and stress response. Analysis of the promoter sequences showed AACTAAA, ABRE and G-box elements (pollen-specific, ABA-responsive and stress-inducible motif respectively), suggesting appropriate transcriptional regulation consistent with its expression profile. As a whole, the findings revealed that AT5G35460 is an unexplored membrane-localized acyltransferase involved in lipid maintenance during reproductive development and environmental responses. This study serves as a basis for subsequent functional characterization and identifies AT5G35460 as a potential target for modifying pollen viability, senescence kinetics and stress tolerance in plants. Full article

Winter oilseed rape achieves frost tolerance through cold acclimation, which develops naturally in autumn in response to low but non-freezing temperatures. However, ongoing climate change has led to an increasing instability in winter temperatures, with more frequent warm breaks. Such temperature fluctuations can induce deacclimation, resulting in a partial or complete loss of frost tolerance and reduced winter survival. Water management is a critical determinant of plant survival under such conditions, yet its regulation during the acclimation–deacclimation transition remains incompletely understood. This study investigated tissue-specific changes in key components of water management in winter oilseed rape subjected to non-acclimated, cold-acclimated, and deacclimated conditions. Proline accumulation, abscisic acid content in plant tissue and cell sap, and the expression of aquaporin genes BnPIP2 and BnTIP1 were analyzed in leaves, root necks, and roots. Cold acclimation induced a strong accumulation of proline and ABA, accompanied by marked downregulation of aquaporin expression in all tested tissue. Deacclimation resulted in partial reverse of proline and ABA. Aquaporins expression demonstrated tissue-specific recovery, showing increases in all tissue compared to cold-acclimated plants. Our findings demonstrate that coordinated actions of integrated water transport, osmotic adjustment, and hormonal signaling in regulating water balance and frost tolerance during winter temperature fluctuations. Full article

In the process of maize production, extreme meteorological conditions such as drought and high temperature are often the main environmental stress factors affecting pollination efficiency. Previous studies have shown that, under adversity, the germination rate of pollen grains on the filaments of female spikes directly affects the success rate of reproduction and ultimately determines the grain yield. This study focuses on a cysteine protease named ZmPCP. The expression of this protease in maize pollen is significantly higher than in other tissues, and its specific function has not been clearly defined. Its localization in the cell membrane or apoplast was further confirmed by transient transfection experiments and plasmolysis. The interaction between ZmPCP and ZmSNAP33 was verified by yeast two-hybrid technology and a GST pull-down experiment, indicating that ZmPCP may affect pollen germination and stress resistance by regulating vesicle transport. Secondly, by analyzing the pollen germination rate of maize inbred lines B104, ZmPCP-KO and ZmPCP-OE transgenic maize plants, we found that ZmPCP overexpression could significantly enhance pollen viability and pollen tube growth under drought stress. After 1 h of short-term drying treatment, the pollen germination rate of the ZmPCP-OE line was maintained at 44%, which was significantly higher than that of the other lines. In addition, the observation of pollen tube growth showed that ZmPCP overexpression could promote the extension of pollen tubes in the filament. Moreover, a transcriptome sequencing analysis revealed the regulatory effects of ZmPCP on pollen in multiple biological processes, including stress response, carbohydrate metabolism, growth and development, cell wall material metabolism, signal transduction, etc. The involved pathways of these differential genes indicate that ZmPCP enhances pollen drought tolerance and promotes pollen tube growth through a “metabolism signal structure”. In the germination experiment on the seventh day, the germination rate of ZmPCP-OE maize seeds was the lowest, indicating that its overexpression inhibited seed germination. At the same time, ZmPCP-overexpressing Arabidopsis showed a significant advantage in taproot growth under high-concentration ABA stress. ZmPCP provides an important theoretical basis for regulating the pollination process and improving the pollination efficiency of maize varieties through interaction with ZmSNAP33. Full article

Cadmium (Cd) is a highly toxic heavy metal that severely impairs plant growth and poses ecological and health risks. Chrysanthemum indicum (L.), a dominant species in Cd-contaminated regions, represents a valuable germplasm for phytoremediation. In this study, we cloned and characterized CiWRKY50, a WRKY transcription factor containing a conserved WRKY domain and C2H2-type zinc finger. CiWRKY50 was localized to the nucleus but lacked intrinsic transcriptional activation activity. Overexpression of CiWRKY50 in Arabidopsis thaliana and C. indicum significantly enhanced Cd tolerance, as shown by reduced root Cd accumulation, improved transport efficiency, lower ROS and MDA levels, and increased chlorophyll, proline, and soluble protein contents. Antioxidant enzyme activities and Cd-chelating compounds (GSH, NPT, PCs) were also upregulated. Furthermore, combined Cd and ABA treatments promoted Cd sequestration in roots and activated ABA-responsive genes (CiABF1, CiABF2, CiABF4), alleviating shoot toxicity. These findings indicate that CiWRKY50 enhances Cd tolerance in association with enhanced ABA-mediated signaling and redox homeostasis, providing new insights for breeding Cd-resistant plants and improving phytoremediation strategies. Full article

The Xinjiang wheat variety ‘Xindong 22’ was used as experimental material. Two soil moisture treatments were established: control (CK, 70–75% field capacity), drought (X1, 60–65%). The photosynthetic characteristics and resistance physiological indexes of wheat leaves under different stress levels were analyzed, and RNA-Seq technology was used to conduct transcriptome sequencing and analysis were performed on wheat leaves. The results showed that under drought stress, superoxide dismutase (SOD) activity was significantly enhanced, while peroxidase (POD) activity decreased. Soluble sugar and proline contents also increased. These changes likely enhanced reactive oxygen species scavenging, thereby reducing the content of malondialdehyde in the leaves. Meanwhile, under the X1 treatment, stomatal conductance and transpiration rate of wheat leaves showed a slow decreasing trend, the intercellular CO₂ concentration decreased slightly, the decline in Fv/Fm was relatively small, and the value of the non-photochemical quenching coefficient gradually increased. Transcriptome analysis identified 1881 differentially expressed genes (DEGs). Notably, drought stress induced the up-regulation of key genes involved in the ABA signaling pathway (e.g., SnRK2 and ABF) and the MAPK cascade, suggesting their crucial roles in mediating drought responses in this wheat variety. In the jasmonic acid signaling pathway, MYC2 functions as a positive regulator by interacting with JAZ proteins. These findings demonstrate that Xinjiang wheat employs integrated physiological and molecular strategies to cope with drought stress. Full article

Valsa canker, caused by Valsa pyri (Vp), severely threatens global pear production. The VAMP72 family modulates plant immunity, but its role in Valsa canker resistance remains unclear. In this study, it was found that PbeVAMP724, encoding a membrane-localized SNARE protein, was significantly induced by Vp infection and Abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA) in the resistant pear rootstock Pyrus betulaefolia. Transient overexpression of PbeVAMP724 in ‘Huangguan’ fruits reduced Vp-induced lesions, and the lesion diameter was reduced by 23.1% at 48 h and 20.0% at 72 h compared to the empty vector control (pFGC-5941), whereas VIGS silencing compromised the resistance. Stable overexpression in suspension cells ‘Duli-G03’ (P. betulifolia) enhanced tolerance to Vp metabolites (VpM), alleviated cell death, and induced ROS bursts and defense responses. Weighted gene co-expression network analysis (WGCNA) revealed that phloem/xylem histogenesis-related genes (GWHGAAYT028948, GWHGAAYT039435) are co-expressed with PbeVAMP724. In conclusion, we demonstrate that PbeVAMP724 integrates hormone signaling, triggers ROS bursts, and activates defense responses to positively regulate resistance to Valsa canker in pear, representing a promising candidate for breeding Valsa canker-resistant pear varieties. Full article