Search Results (259)

Strawberry is a globally important yet stress-sensitive crop, increasingly threatened by combined abiotic and biotic stresses. Unlike single stresses, combined stresses elicit unique, non-additive responses through complex signaling and gene regulatory networks. This review synthesizes current knowledge on the molecular mechanisms underlying strawberry responses to combined stresses, focusing on signal perception and transduction as well as gene regulation. We examine how combined stresses are perceived by membrane-localized sensors and calcium channels, and how these signals are transduced through MAPK (mitogen-activated protein kinase) cascades, CDPKs (calcium-dependent protein kinases), and hormonal crosstalk involving ABA (abscisic acid), JA (jasmonic acid), and ethylene. At the gene regulation level, we discuss the roles of key transcription factors (WRKY, NAC (NAM, ATAF1, ATAF2 and CUC2), GRAS (GAI-RGA-and-SCR), DREB (Dehydration-Responsive Element-Binding protein), bZIP (basic leucine zipper transcription factor), CAMTA (calmodulin-binding transcription activator), ARF (auxin response factor), and LAV (Leafy Cotyledon2–Abscisic Acid Insensitive3–Val)), transcriptional cascades, epigenetic regulation via DNA methylation, and post-transcriptional (miRNAs such as Fan-miR73) and post-translational (ubiquitination and phosphorylation) control mechanisms. The review also evaluates emerging mitigation strategies informed by these molecular insights, including genomic selection, and explores future directions such as CRISPR (clustered regularly interspaced short palindromic repeats)-based genome editing and multi-omics integration. We conclude that understanding the integrated signaling and gene regulatory networks is essential for developing climate-resilient strawberry cultivars capable of withstanding increasingly complex stress combinations. Full article

Waterlogging is a major abiotic stress that restricts maize growth and yield. WRKY transcription factors play important roles in plant stress responses; however, the functions of many maize WRKY members in waterlogging tolerance remain poorly understood. In this study, we investigated the role of ZmWRKY83 in maize responses to waterlogging. ZmWRKY83 expression was significantly downregulated in maize roots under waterlogging stress. Functional analysis showed that ZmWRKY83-overexpressing lines exhibited growth comparable to that of wild-type plants under normal conditions but more severe growth inhibition and lower shoot and root fresh weights after waterlogging treatment. Physiological analyses further revealed that ZmWRKY83 overexpression impaired adventitious root formation, increased membrane damage, and reduced antioxidant capacity under waterlogging conditions. Transcriptome analysis revealed that the differentially expressed genes were primarily enriched in plant hormone signal transduction, secondary metabolism, and phenylpropanoid biosynthesis. Further investigation identified the auxin-responsive gene ZmIAA7 as a potential downstream target of ZmWRKY83. qRT-PCR, DLR, and Y1H assays indicated that ZmWRKY83 directly binds to the ZmIAA7 promoter and represses its transcriptional activity. Collectively, these findings suggest that ZmWRKY83 negatively regulates maize waterlogging tolerance by suppressing auxin-related responses through ZmIAA7, expanding the regulatory network underlying WRKY-mediated responses to waterlogging in maize. Full article

Soil moisture plays a crucial regulatory role in determining the size and quality of citrus fruits. This study analyzed the fruit size and quality of citrus under different soil moisture conditions, including severe drought (SD), moderate drought (MD), and control (CK). Under drought stress, the fruit weight, longitudinal diameter, and transverse diameter of citrus fruits were significantly lower than those of the control. The content of soluble solids and titratable acid in fruits under drought stress was significantly higher than that of the control. Transcriptome sequencing revealed that compared with CK, there were 1186 differentially expressed genes in MD, including 414 up-regulated genes and 772 down-regulated genes; and 2315 differentially expressed genes in SD, including 1143 up-regulated genes and 1172 down-regulated genes. The differentially expressed genes were significantly enriched in cellular processes, metabolic processes, and plant hormone signal transduction. The down-regulated expression of auxin and gibberellin biosynthesis genes (YUC10, GA20_OX1, GA2_OX1, and GA20_OX2) and signal transduction-related genes (AUX/IAA13, SAUR32, GH3.1, and ARRs), and the up-regulated expression of cytokinin decomposition gene (CKX5) may be associated with reduced fruit size under drought conditions. The up-regulated expression of citric acid synthesis genes (PEPC2 and PEPCK1) and vacuolar transporters (PH1, PH4, PH8, and VHA-c3) may be associated with pronounced accumulation of citric acid in citrus under drought stress. In conclusion, water control regulated fruit size and acidity by modulating phytohormone metabolism and signaling, along with the synthesis and transport of citric acid. Full article

Plants are constantly exposed to a wide range of abiotic stresses that have significant negative impacts on growth and yield. Plant acclimation to these stresses is governed by integrated classical phytohormone and plant peptide hormone signalling networks that control the ability of a plant to survive and adapt to extreme environments. Classical phytohormones, including abscisic acid, auxins, gibberellins, cytokinins, jasmonates, salicylic acid, brassinosteroids, and the recently recognised phytomelatonin, act in concert with peptide-based plant hormones, among which C-terminally encoded peptides (CEPs) play prominent roles in coordinating stress perception, signal transduction, and adaptive responses throughout the plant. These integrated networks control stomatal behaviour, photosynthesis, osmolyte and antioxidant levels, root architecture, and energy metabolism, thereby helping plants maintain homeostasis and optimise survival while sustaining minimal growth under unfavourable conditions. Under stressful conditions, these networks do not operate in isolation but form highly dynamic, context-dependent regulatory circuits in which each physiological process is simultaneously regulated by multiple hormones acting through convergent and overlapping signalling pathways. Phytomelatonin has emerged as a particularly important integrative node within these networks, functioning both as a potent direct antioxidant through sequential ROS-scavenging catabolite cascades and as a bidirectional regulator of classical phytohormone signalling under diverse abiotic stresses. New technologies in the fields of transcriptomics, proteomics, phosphoproteomics, metabolomics, and systems biology have provided new information on the dynamic relationships between classical phytohormones and plant peptide hormones, revealing candidate regulatory nodes and transcription factor networks that mediate stress adaptation at molecular, biochemical, and physiological levels. However, it is important to distinguish between correlative associations identified through omics profiling and causal regulatory relationships validated through rigorous genetic and biochemical experimentation, as most omics-derived candidates remain to be functionally established. Empirical studies demonstrate how these networks can be used to improve crops by increasing stress tolerance through modulating classical phytohormone and plant peptide hormone signalling, including through exogenous phytomelatonin application, CRISPR-mediated hormone pathway editing, and CEP pathway manipulation, to produce resilient cultivars without reducing yields. Although these advances represent significant progress, challenges remain, including the inherent complexity and redundancy of the networks, context-dependence and severity-dependence of hormonal responses, the persistence of a significant translational gap between laboratory findings and field application, and incomplete mechanistic understanding of peptide hormone roles under combined stress conditions. Addressing these challenges will require integrative multi-omics approaches, higher-order computational modelling, and rigorous field-based functional validation alongside emerging tools such as synthetic biology and precision breeding. Full article

Ginger possesses both significant edible and medicinal value. Sprouting of ginger is a critical phase that influences the yield and quality of the crop. While silica nanoparticles (SiNPs) are known to promote the growth of ginger, their impact on sprouting remains unclear. The results show that sprouting 100 mg L⁻¹ SiNPs (SiNP100) significantly improved ginger sprouting rate and respiratory intensity while reducing weight loss. It also elevated fructose, sucrose, and glucose contents, as well as sucrose phosphate synthase (SPS), sucrose synthase (SS), neutral invertase (NI), acid invertase (AI) activities, indicating that SiNP100 is associated with enhanced sprouting by modulating sugar metabolism. Concurrently, starch content decreased and α- and β-amylase activities increased. Hormonal profiling showed that SiNP100 increased auxin (IAA), trans-zeatin (TZR), isoamylalkenyladenin (IP), and gibberellic acid (GA₃) levels, while decreasing abscisic acid (ABA), further supporting its role in promoting sprouting. RNA-seq and RT-qPCR validated that SiNP100 significantly enriched the plant hormone signal transduction and starch and sucrose metabolism pathways, upregulating genes related to sugar transport and metabolism (ZoSweet7, ZoSSIVa, ZoSPS1, and ZoSUS5). Field trials over two consecutive years confirmed that SiNP100 application improved ginger growth, photosynthesis, antioxidant capacity, and ultimately yield and quality. This study demonstrated the potential of SiNPs to improve seed sprouting and promote ginger growth under field conditions. Full article

Soybean (Glycine max L.) yield is critically influenced by the number of nodes on the main stem (MSN), which serves as the primary site for pods and seeds. To elucidate the genetic mechanisms underlying MSN, we conducted a multi-omics analysis integrating bulk segregant analysis sequencing (BSA-seq), phytohormone, and transcriptome profilings in a soybean mutant, LSD914, which exhibits a significantly increased MSN number compared to its wild-type parent, HN48. BSA-seq of an F2 population identified 27 candidate genomic regions spanning 2.92 Mb, primarily on chromosome 18. Within these regions, 149 genes harbored non-synonymous SNPs and 26 genes contained frameshift InDels, with functional enrichment pointing to pathways in plant hormone signal transduction and developmental regulation. Phytohormone profiling revealed a distinct shift in LSD914, characterized by down-regulation of jasmonates, salicylates, and auxins, alongside specific accumulation of cis-zeatin. Integrative transcriptome analysis identified Glyma.18G259400, a gene encoding a gibberellin-regulated protein (GmGASA32), which was consistently and significantly down-regulated in LSD914 across all developmental stages and tissues. This finding contrasts with previous reports of its overexpression promoting plant height, suggesting a nuanced, context-dependent regulatory role. Our integrated approach identifies a key set of candidate genes and highlights GmGASA32 as a pivotal node in a hormone signaling network that orchestrates soybean node number, providing valuable targets for breeding high-yield soybean varieties with optimized plant architecture. Full article

Cold stress (CS) represents a major environmental factor that adversely affects plant growth, development, and productivity. To cope with low-temperature conditions, plants have evolved sophisticated mechanisms for CS perception and response, mediated through complex cellular signaling networks and physiological processes. Central to these adaptive responses are phytohormones, which function either independently or through synergistic and antagonistic interactions to fine-tune CS tolerance. This review synthesizes current knowledge on the roles of major classical phytohormones and signaling metabolites in regulating CS tolerance in plants. We first outline the molecular mechanisms involved in CS sensing and signal transduction, highlighting the roles of membrane-associated sensors, calcium signaling, and downstream transcriptional networks. Then, we discuss the contributions of key classical phytohormones, including auxin, abscisic acid, ethylene, salicylic acid, cytokinin, jasmonic acid, brassinosteroids, gibberellic acid, strigolactones, and signaling metabolites, including melatonin and gamma-aminobutyric acid, to CS tolerance, highlighting their individual and interacting roles in modulating gene expression regulation, antioxidant defense and physiological adaptations. We also discuss the crosstalk between these hormones, emphasizing the dynamic and often context-dependent nature of their interactions in response to CS. Furthermore, the review highlights recent advances in CRISPR/Cas9-based genome editing strategies targeting phytohormone biosynthesis, signaling, and response pathways to improve CS tolerance in plants. By integrating hormonal signaling, molecular regulation, and modern biotechnological tools, this review provides a comprehensive framework for understanding phytohormone-mediated CS adaptation and offers perspectives for developing climate-resilient crops through genetic and agronomic approaches. Full article

Soil salinization is one of the major abiotic stresses that influences agricultural production and the environment. Auxin response factors (ARFs) are key components of the auxin signal transduction pathway, while their role in wheat salt stress responses remains unclear. In this study, we identified TaARF18 as a negative regulator of salt tolerance in wheat. The coding sequences of TaARF18-A, TaARF18-B, and TaARF18-D were 2106, 2088, and 2088 bp, respectively. TaARF18 is a hydrophilic protein featuring typical Auxin-resp and B3 DNA-binding domains and exhibits relatively high evolutionary conservation among Poaceae species. The expression of TaARF18 was upregulated under salt stress. TaARF18 predominantly accumulated in the nucleus. Silencing of TaARF18 via the BSMV-VIGS approach enhanced salt tolerance in wheat seedlings. In addition, haplotype analysis based on resequencing data from 355 wheat accessions identified 25, 31, and 16 haplotypes for TaARF18-A, TaARF18-B, and TaARF18-D, respectively. Fourteen wheat accessions carrying different haplotypes were evaluated under salt stress, and HapIII of TaARF18-A exhibited the highest level of salt tolerance, which can act as a strong selection locus in global wheat breeding. Our findings provide insight into the function of ARFs in salt stress responses and offer a potential target for CRISPR/Cas-mediated salt-tolerant wheat breeding programs. Full article

2,4-Dichlorophenoxyacetic acid (2,4-D) is a vital exogenous auxin for the induction and proliferation of litchi embryogenic callus. At present, its molecular regulation mechanism remains unclear. In this study, transcriptome sequencing samples were selected based on different cell growth phenotypes observed in ‘Feizixiao’ litchi embryogenic callus cultured in liquid medium with or without 2,4-D. By integrating transcriptome profiling with weighted gene co-expression network analysis (WGCNA), we identified key genes and signaling pathways dynamically responsive to 2,4-D concentration changes. We identified 558 commonly differentially expressed genes (DEGs), of which 117 were up-regulated and 387 were down-regulated; functional enrichment analysis revealed significant enrichment in the “plant hormone signal transduction” and “phenylpropanoid biosynthesis” pathways. In the former pathway, genes such as AUX28, GH3.17, GH3.6, and ARR5 were up-regulated; in the latter, by comparison, β-glucosidase 47 and Peroxidase 61 exhibited increased expression levels induced by 2,4-D. Furthermore, among these DEGs, 57 transcription factors belonged to 24 families. Notably, VRN1, FEZ, and DOF5.4 were significantly and rapidly induced by 2,4-D. WGCNA results demonstrated a significant positive correlation between the yellow module and 2,4-D treatment. Small heat shock protein (sHSP) genes constituted the core hub genes in the yellow module. Through Venn analysis of DEGs and key modules, 38 cross-genes were identified, of which non-specific lipid-transfer protein-like genes (nsLTP) were found to be specifically up-regulated without 2,4-D. The transcription factors and genes identified work in synergy to ensure the formation and sustained proliferation of embryogenic callus by precisely regulating the dynamic balance of auxin and cytokinin within cells and maintaining the stability of cell structure. Our findings provide a crucial theoretical foundation for understanding the molecular mechanism of 2,4-D in regulating litchi embryogenic callus proliferation. Full article

Phelipanche aegyptiaca is a root parasitic weed that causes severe yield losses in tomato production. Current control methods are constrained by limited efficacy and environmental concerns. Although biocontrol microbes and amino acids have each been reported to suppress broomrape parasitism individually, their synergistic effects and underlying molecular mechanisms remain largely unexplored. This study evaluated the biocontrol performance of Bacillus velezensis strain N35, applied alone or in combination with five amino acids (methionine, isoleucine, valine, histidine, and proline), against P. aegyptiaca parasitism in tomato using pot experiments coupled with transcriptomic profiling of host roots. Both individual and combined treatments significantly reduced the number and fresh weight of P. aegyptiaca parasitic tubercles. Notably, the combinations of methionine + N35 and isoleucine + N35 achieved near-complete suppression of parasitism. Transcriptomic analysis revealed extensive reprogramming of gene expression in tomato roots, with significant enrichment in pathways associated with plant hormone signal transduction, MAPK signaling, phenylpropanoid biosynthesis, and carotenoid biosynthesis. The synergistic treatments coordinately activated ethylene, jasmonic acid, and salicylic acid-mediated signaling, while suppressing auxin and abscisic acid signaling. Moreover, key strigolactone biosynthesis genes (CCD7 and CCD8) were strongly downregulated, and specific genes involved in the biosynthesis of defense-related secondary metabolites were selectively upregulated. Collectively, these findings demonstrate a pronounced synergy between B. velezensis N35 and specific amino acids in suppressing P. aegyptiaca parasitism. This enhanced host resistance is achieved through the coordinated reprogramming of hormonal and metabolic networks, particularly via interference with strigolactone-mediated germination signal secretion. This study provides a theoretical basis for the development of microbe–metabolite synergistic strategies as sustainable and environmentally benign alternatives for broomrape management. Full article

The formation of adventitious roots plays a key role in plant asexual reproduction, yet research on this process in pepper remains limited. Exogenous auxin treatment substantially promotes adventitious root formation in pepper, and we identified CaLBD16 as a positive regulator acting downstream of auxin signaling. Further analysis revealed that the signal transduction from auxin to CaLBD16 is mediated through the activation of CaARF6 and CaWOX11, both of which also contribute to adventitious root formation. Together, our findings uncover a molecular mechanism underlying auxin-induced adventitious root formation in pepper, offering valuable insights for its practical application in production. Full article

Corolla movement is a typical plant movement behavior that enables plants to optimize pollination and adapt to environmental changes. Nevertheless, its molecular mechanism remains poorly understood. In the present study, we conduct a comprehensive transcriptome analysis of Mirabilis jalapa (Nyctaginaceae) corolla at five stages (AG-EG) to elucidate the regulatory networks underlying movement. The results showed that the differentially expressed genes (DEGs) were mainly associated with cellular processes, catalytic activity, MAPK signaling, plant hormone signal transduction, and photosynthesis-related pathways, highlighting their involvement in corolla dynamics. Transcriptome profiling further demonstrated that auxin, ethylene, and abscisic acid signaling pathways were key hormonal regulators of corolla movement. Moreover, Ca²⁺ transport genes (CNGCs and CMLs) and respiratory burst oxidase homologs (RBOHs) were significantly enriched, indicating that Ca²⁺–ROS signaling oscillations also play an important role in driving differential cell expansion and turgor changes. Transcription factor analysis also revealed the upregulation of WRKY2, WRKY22, and WRKY33, suggesting that WRKYs act as the critical transcriptional regulators linking ROS–Ca²⁺ signals with downstream gene expression. The reliability of RNA-Seq data was confirmed by RT-qPCR, which showed high consistency with transcriptome profiles. These findings suggested that corolla movement in M. jalapa is carried through the integration of hormonal pathways, Ca²⁺–ROS signaling, and WRKY-mediated transcriptional regulation. This research provided novel insights into the molecular basis of plant movement and established a foundation for further study on floral dynamics and adaptive strategies in angiosperms. Full article

Cadmium (Cd) is widely dispersed in the environment and has emerged as a major environmental contaminant. Although Salix viminalis shows potential for phytoremediation of Cd pollution, the defence mechanism of its roots against heavy metals remains unclear. This study explores the adaptive response of S. viminalis roots to Cd stress from physiological, transcriptomic, and metabolomic perspectives. The results suggest that Cd stress exerts inhibitory effects on root growth and development. Compared with the control (Cd-free), the root volume and dry weight of S. viminalis exposed to Cd decreased by 26% and 29%, respectively. After exposure to Cd stress for 14 and 21 days, the Cd content in the roots increased by 117-fold and 134-fold, the hydrogen peroxide content increased by 89% and 110%, and the malondialdehyde content increased by 82% and 88%, respectively. This phenomenon can be attributed to the fact that the continuous accumulation of Cd in the roots may have aggravated the degree of lipid peroxidation. A total of 9171 differentially expressed genes (DEGs) and 169 differential metabolites (DIMs) were identified through transcriptomic and metabolomic analyses. Further combined analyses revealed the potential roles of several pathways in the defensive response of S. viminalis roots against Cd stress, including plant hormone signal transduction, thiamine metabolism, glycolysis, glycerophospholipid metabolism, and other pathways. Notably, the feedback regulatory effects formed by thiamine metabolism and hormone signal transduction related to auxin, jasmonic acid, and salicylic acid play a crucial role in the early stage when roots are exposed to Cd stress. These effects mobilized osmotic adjustment in roots by enhancing saccharide metabolism and activated the Cd detoxification process by altering lipid metabolism, thereby contributing positively to the defence of willow roots against Cd stress. These findings provide insights into the adaptive mechanism of S. viminalis roots in response to Cd and the application of fast-growing woody plants in heavy metal phytoremediation. Full article

Background: Protein phosphatase 2Cs (PP2Cs) constitutes the largest phosphatase family in plants, playing a pivotal role in signal transduction. Within this family, the PP2C.D subfamily exerts significant influence on cell elongation and stress adaptation by mediating the ‘SAUR-PP2C.D-H+-ATPase’ regulatory module in the auxin signaling pathway. In rice, OsPP2C61 is a PP2C member whose molecular features and potential regulatory context remain unclear. Methods: Our study conducted a preliminary characterization of OsPP2C61 through integrated bioinformatics analysis, spatiotemporal expression profiling, and subcellular localization experiments in tobacco leaf cell. Results: OsPP2C61 encodes a 377-amino-acid protein predicted to be hydrophilic, basic, and structurally unstable. Secondary-structure prediction identified three major elements with random coils as the predominant component, whereas 3D modeling indicated alternating α-helices and β-sheets consistent with a canonical PP2C fold. Phylogenetic inference placed OsPP2C61 within the PP2C.D clade and revealed conserved motifs shared with OsPP2C25, OsPP2C28, and OsPP2C39. Promoter analysis showed enrichment of abscisic acid (ABA)- and methyl jasmonate (MeJA)-responsive elements along with multiple stress-related cis-regulatory motifs. Spatiotemporal expression analysis showed that OsPP2C61 is highly expressed in roots. Subcellular localization assays further demonstrated that the OsPP2C61-GFP fusion protein localizes to the nucleus and the plasma membrane when transiently expressed in epidermal cells of Nicotiana benthamiana. Conclusions: This work delivers the first comprehensive characterization of OsPP2C61, establishing a foundation for mechanistic studies and positioning OsPP2C61 as a candidate gene for rice improvement. 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