Search Results (1,097)

Salinity is a major constraint to crop productivity. Beneficial plant–fungus interactions represent a promising strategy to enhance stress resilience. Here, we investigated fungal endophytes isolated from the roots of Oryza sativa cultivated in saline-prone marshlands of the Guadalquivir River, Spain. From a collection of 38 isolates, five salt-tolerant strains exhibiting plant growth-promoting activity were identified, including a previously uncharacterized Reticulascus sp. strain S5. Co-cultivation assays with the non-native host plant Arabidopsis thaliana demonstrated that S5 increased the root and shoot biomass under salt stress. To elucidate the underlying molecular mechanisms, a comprehensive RNA-Seq analysis of the roots and shoots under control and saline conditions was performed. Fungal colonization induced pronounced transcriptomic changes, particularly in the shoots, including rewiring of the auxin- and abscisic acid-related pathways and the induction of genes associated with cell wall remodeling. Concurrently, defense-related processes, including glucosinolate biosynthesis and ethylene signaling, were broadly repressed, suggesting attenuated stress perception in colonized plants. In the roots, S5 inoculation suppressed the expression of genes involved in root hair development and cell wall organization, indicating a fungus-driven reconfiguration of root development. Moreover, comparative analysis with Fusarium sp. K-23, a fungus that has previously been demonstrated to promote plant growth under salinity stress, revealed distinct root-associated mechanisms but convergence on a shared regulatory module in shoots involving ABA-responsive transcription factors and osmotic stress regulators. Collectively, our findings demonstrate that Reticulascus sp. S5 enhances plant salt stress tolerance through the coordinated transcriptional reprogramming of growth, hormone signaling, and stress responses, highlighting a possible potential of habitat-adapted endophytes for sustainable crop improvement. Full article

Brassinosteroids (BRs) are essential steroidal phytohormones that regulate plant growth, development, and responses to environmental stresses. Recent studies have demonstrated the important roles of BRs in enhancing plant tolerance to abiotic stresses, including drought, salinity, temperature extremes, heavy metal toxicity, and oxidative stress, as well as biotic stresses caused by pathogens and herbivores. This review summarizes current advances in BR biosynthesis, metabolism, transport, and signaling pathways, focusing on key components that mediate stress adaptation. We discuss the physiological and molecular mechanisms through which BRs improve stress tolerance, including regulation of antioxidant defense, ion homeostasis, osmotic adjustment, and stress-responsive gene expression. Particular attention is given to the extensive cross talk between BRs and other phytohormones, such as abscisic acid, jasmonic acid, salicylic acid, ethylene, auxin, and gibberellins, which enables plants to balance growth and defense under adverse conditions. Furthermore, we highlighted the potential applications of BRs in crop improvement through exogenous treatments, genetic engineering, and genome-editing approaches. However, the effectiveness of BR-based strategies is highly dependent on crop species, developmental stage, stress type, BR concentration, application method, and environmental conditions. In addition, excessive BR accumulation or application may result in undesirable growth responses, and further multi-location field validation is required before widespread agricultural implementation. Finally, we discuss emerging research trends, current knowledge gaps, and future perspectives for exploring BR signaling to develop climate-resilient crops. Overall, BRs represent promising targets for improving crop stress resilience; however, optimizing BR-mediated strategies and validating their long-term performance under diverse field conditions will be essential for their successful application in sustainable agriculture. Full article

The universal stress protein (USP) family is a large but poorly studied group of plant proteins whose roles are considered primarily in the context of stress tolerance. This study demonstrates that the functions of USPs are not limited to the stress response but also influence plant developmental processes, namely, the regulation of seed germination and seedling establishment. Using reverse genetics, we found that disruption of the Arabidopsis thaliana At3g58450 gene, encoding germination-related USP (GRUSP), results in delayed germination and abscisic acid (ABA) hypersensitivity in the mutant the GABI-kat 115C08 (grusp-115) knockout line. This hypersensitivity was only partially rescued by the application of fluridone, an ABA biosynthesis inhibitor. Altered ABA content and expression patterns of genes involved in ABA metabolism and signaling, along with a decrease in the mRNA levels of gibberellin (GA) oxidases in dry and either Murashige and Skoog (MS)- or ABA-imbibed mutant seeds, indicate that GRUSP function is primarily associated with seed imbibition and early germination stages. Furthermore, the grusp-115 mutant showed upregulation of ABI5 transcripts in imbibed seeds and seedlings as well as an accumulation of ABI5 protein level under excess GA conditions, indicating a functional relationship between these proteins. Hence, GRUSP is a novel component of the GA and ABA pathways whose function is initiated during seed germination. Full article

Salinity stress is one of the major stressors that limits yield potential in field crops. Salinity-led imbalances in ionic and water potential, as well as oxidative damage, impair photosynthesis. Plant-growth-promoting rhizobacteria (PGPRs) have been demonstrated to mitigate salinity-stress-induced damage through various mechanisms such as biofilm and exopolysaccharide production, modulation of plant root architecture or molecular signaling involving modulation of sodium/potassium efflux transporters. PGPRs are known to induce biosynthesis and signaling of various phytohormones in plants. PGPR-derived phytohormones can in turn regulate molecular signaling involved in maintaining ion fluxes, preventing salinity-induced senescence, and reinforcing plant root architecture, thereby maintaining plant growth and development under saline conditions. In this review, we provide comprehensive advances on how PGPRs modulate and integrate biosynthesis and/or signaling of various phytohormones, such as auxins, cytokinins, gibberellin, ethylene, abscisic acid, salicylic acid, jasmonates, brassinosteroids and strigolactones, to reshape plant architecture, physiological and biochemical responses in plants under salinity. We integrate molecular evidence with morpho-physiological studies and propose a phytohormone-centric framework to select strains that optimize growth, ion homeostasis and plant stress resilience under salinity. Full article

Soil salinization stands out as a major factor contributing to the shrinkage of arable land. This study explored the salt tolerance mechanism of tillers in CMG and 9311 by evaluating morphophysiological, transcriptomic, and metabolomic characteristics under 0.3% NaCl stress. The activities of SOD, POD, and APX in the tiller nodes of the salt-tolerant variety CMG were higher than those of 9311, while the levels of MDA and hydrogen peroxide in the tiller nodes of CMG were relatively low. Both varieties responded to salt stress mainly by activating pathways such as amino acid metabolism (alanine, aspartic acid, glutamic acid metabolism, and arginine biosynthesis), amino acid acyl-trNA biosynthesis, oxidative phosphorylation, and phenylpropanin biosynthesis. The varieties differed in that CMG tillering nodes also have unique pathways of “glycerophospholipid metabolism” (related to membrane lipid remodeling) and “biosynthesis of the cuticle, suppositories and waxes”, which can effectively reduce water loss and prevent sodium ions from entering. In addition, CMG can regulate more plant hormone signaling pathways to coordinate the expression and metabolic activities of downstream defense genes, such as abscisic acid (ABA) and jasmonic acid (JA), and other hormone signals. After salt stress, the CMG tiller nodes tend to strengthen themselves, enabling them to resist stress and reduce Na⁺ toxicity, while the 9311 tiller nodes, under the condition of activating basal metabolism, transfer to the leaves to enhance photosynthetic efficiency and resist stress. Through comprehensive screening and analysis of the genes and metabolites of CMG and 9311 tillers under salt stress, the molecular mechanisms and metabolic pathway dynamics involved in their salt stress response were identified, thus providing a new perspective for in-depth research on rice salt tolerance mechanisms. Full article

Fruit firmness is a pivotal agronomic and commercial trait that determines the storability, transport tolerance and edible quality of tomato (Solanum lycopersicum L.). Fruit softening severely restricts postharvest performance and economic benefits of tomato products worldwide. This review summarizes the latest research progress on factors and regulatory mechanisms governing tomato fruit firmness. Multiple environmental factors including temperature, light, moisture and atmospheric composition jointly affect cell wall structure and metabolism, thereby altering fruit firmness. Mineral nutrition, postharvest handling and pathogen infection also exert profound impacts on texture characteristics by modulating physiological activities and cell wall integrity. Phytohormones such as gibberellin, ethylene, abscisic acid, jasmonic acid and salicylic acid form complex signaling crosstalk to mediate fruit softening processes. Furthermore, we elaborate on the functions of transcription factors, quantitative trait loci, and key functional genes, as well as research advances in transcriptomics and metabolomics, including transcriptome analyses identifying differentially expressed genes related to cell wall remodeling, and metabolomic profiling revealing hydroxyproline and galacturonic acid as firmness-associated markers. Cell wall metabolism is confirmed as the core pathway controlling fruit softening. Finally, future research directions are proposed, focusing on single-cell and spatial transcriptomics to map softening regulatory networks, AI-driven predictive modeling for softening kinetics and shelf-life optimization, and CRISPR/Cas9-based gene editing for precise trait improvement. Full article

Wheat is a globally important staple crop, whose growth and yield formation rely on the precise regulation of phytohormone signaling. The PR10/Bet v 1 (Pathogenesis-related protein 10/Betula verrucosa 1) family consists of conserved small-molecule ligand-binding proteins that participate in phytohormone signaling and plant development; however, systematic investigations of this family in wheat remain limited. Here, we performed a genome-wide identification of 75 PR10/Bet v 1 members in wheat, which were phylogenetically classified into three subfamilies: 21 known members belonging to the PYL (Pyrabactin resistance 1-like) subfamily, and 54 members assigned to two previously uncharacterized subfamilies. Bioinformatic analyses revealed that whole-genome/segmental duplication has driven the expansion of this gene family, which has evolved under strong purifying selection. Expression profiling and promoter analysis revealed differential expression patterns, along with abundant cis-acting elements responsive to multiple hormones. Quantitative RT-PCR (qRT-PCR) of 12 representative genes revealed marked transcriptional changes in several members within 1 h of treatment with BR (Brassinosteroid), ABA (Abscisic acid), CK (Cytokinin), or SA (Salicylic acid) suggesting that these genes may be directly involved in hormone-regulated processes. This study provides a fundamental framework for exploring the regulatory functions of the wheat PR10/Bet v 1 family, and valuable hormone-responsive candidate genes for the genetic improvement of wheat agronomic traits. Full article

Actinidia arguta possesses great commercial value as an economically important fruit crop, which accumulates abundant nutrients and bioactive components with medicinal potential. However, adverse abiotic environments, especially cold and drought stress, severely restrict its vegetative growth, reproductive development and fruit yield. Numerous studies have established MYB transcription factors as core regulators of plant abiotic stress adaptation. Here, we cloned AaMYB4 from A. arguta ‘Fenglü’ and systematically characterized its function in cold and drought tolerance. AaMYB4 encodes a 241-amino-acid R2R3-MYB protein localized to the nucleus, with highest expression in stems and young leaves. Its transcription is markedly induced by cold, drought and abscisic acid (ABA) within 24 h with a single peak expression pattern. Heterologous overexpression of AaMYB4 in Arabidopsis alleviated cold-induced oxidative damage, accompanied by reduced malondialdehyde (MDA) and reactive oxygen species (ROS) accumulation as well as increased proline contents and enhanced superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities. Virus-induced gene silencing (VIGS)-mediated silencing of AaMYB4 impaired cold tolerance in Actinidia arguta seedlings, while stable AaMYB4 overexpression significantly improved plant survival and physiological performance under cold and drought conditions, concurrent with attenuated ROS accumulation. At the transcriptional level, AaMYB4 overexpression is positively associated with elevated transcript levels of stress marker genes in the ABA signaling and ICE1-CBF-COR pathways. This study lays a theoretical foundation for exploring abiotic stress tolerance mechanisms and conducting stress-resistant molecular breeding in A. arguta. Full article

Plant lipid transfer proteins (LTPs) are key components in defense against biotic and abiotic stresses, yet their functional diversity in Panax ginseng remains unclear. This study aimed to characterize LTP and evaluate its role in stress tolerance. The gene was identified from ginseng transcriptome data and analyzed using bioinformatics tools to determine its structural and physicochemical properties. Panax ginseng lipid transfer protein (PgLTP) was then heterologously expressed in Arabidopsis thaliana (A. thaliana). Transgenic lines were evaluated under fungal infection, drought, and salt stress conditions. Physiological and molecular responses, including reactive oxygen species(ROS) accumulation, malondialdehyde (MDA) content, proline levels, electrolyte leakage, and stomatal behavior under abscisic acid (ABA) treatment, were assessed. Bioinformatic analysis indicated that PgLTP encodes a small protein of approximately 12 kDa containing ten conserved cysteine residues, four α-helices, a signal peptide, and a transmembrane region, suggesting structural divergence from typical LTPs. Functional assays showed that transgenic plants exhibited significantly reduced disease indices under Fusarium oxysporum (F. oxysporum) and Cylindrocarpon destructans (C. destructans) infection. Under drought and salinity stress, transgenic lines demonstrated higher germination and survival rates, enhanced proline accumulation, reduced oxidative damage, and lower electrolyte leakage compared with the wild type. Additionally, PgLTP exhibited enhanced ABA-responsive stomatal closure, which was associated with reduced water loss. These findings indicate that PgLTP contributes to plant tolerance against both biotic and abiotic stresses, which is associated with changes in redox status, osmotic adjustment capacity, and stomatal responses. Full article

Red-flowered strawberry possesses both ornamental and edible value, but its short single-flower lifespan severely limits its ornamental potential. In this study, petals of the red-flowered strawberry cultivar ‘140’ were collected at five developmental stages (large bud, half-bloom, full-bloom, initial withering, and withered) to systematically analyze the senescence process from morphological characteristics, physiological, and ethylene-related gene expression perspectives. The results showed that the epidermal cell breakage rate increased continuously during petal senescence, with lower epidermal cells consistently exhibiting higher breakage rates than the upper epidermal cells. Moisture content decreased progressively, while relative electrolyte leakage, malondialdehyde, hydrogen peroxide, and superoxide anion contents increased continuously. Superoxide dismutase, peroxidase, and catalase activities, as well as glutathione content, exhibited unimodal responses, peaking at different stages. Both ethylene and abscisic acid contents increased and then decreased, with ethylene showing greater amplitude and faster rate of change. The ethylene biosynthesis gene FaACO1 and signaling genes FaETR1, FaETR2, FaEIN2, FaEIN7, FaERF13, and FaERF118 were significantly upregulated at full-bloom or initial withering stages, with FaERF118 showing the highest and continuously increasing expression. These findings indicate that water loss, membrane lipid peroxidation, and reactive oxygen species accumulation synergistically drive petal senescence, with the ethylene signaling pathway playing a key regulatory role. Full article

The seeds of Polygonatum sibiricum exhibit dormancy, which poses a major challenge for its cultivation. To elucidate the regulatory mechanisms underlying dormancy release, we performed integrated transcriptomic and metabolomic analyses on seeds at 0, 5, 10, and 15 d after seed imbibition. Physiological assays revealed progressive declines in abscisic acid (ABA) and starch levels, alongside increases in gibberellin (GA) and soluble sugar contents, reflecting the metabolic changes accompanying the transition from dormancy to germination. Transcriptomic analysis identified 11,520 expressed genes, with 6753, 7775 and 9387 differentially expressed genes (DEGs) at T5, T10, and T15, respectively. KEGG enrichment highlighted starch and sucrose metabolism and plant hormone signal transduction as key pathways. Notably, the GA biosynthesis gene GA3ox was markedly upregulated, while the DELLA repressor (Isoform0012761) showed sustained downregulation, suggesting relieved GA signaling. In the ABA pathway, CYP707A catabolic genes exhibited biphasic expression, and ABA signaling components (PYL, PP2C, SnRK2) showed stage-specific remodeling. A total of 316, 412, and 479 differentially expressed transcription factors were identified across stages, with the GRAS family being the largest. Co-expression network analysis revealed 19 transcription factors integrating starch/sucrose metabolism with ABA and GA signaling, most of which were downregulated, except one C2H2 member showing sustained upregulation. These findings demonstrate that dormancy release in P. sibiricum is governed by coordinated hormonal reprogramming, metabolic mobilization, and transcription factor-mediated regulation, providing a theoretical foundation for improving seed germination in this medicinal plant. Full article

Splicing factors, as core determinants of splice-site selection and dynamic spliceosome assembly, play pivotal roles in stress responses. This review systematically categorizes splicing factors involved in plant abiotic stress responses according to their functions as major spliceosomal components, dividing them into small nuclear ribonucleoproteins (snRNPs) and associated components, spliceosome assembly and disassembly factors, splicing regulatory factors, and proteins related to non-canonical RNA splicing. On this basis, we summarize their regulatory mechanisms of these factors under salt, drought, abscisic acid (ABA) signaling, temperature, and oxidative stresses. Through analyses across multiple species—including Arabidopsis thaliana, rice, maize, soybean, and wheat—we reveal both the evolutionary conservation and species-specific divergence of splicing-factor-mediated regulation. Currently, a large amount of research is still mainly at the transcriptome analysis or single phenotype validation stages, lacking in-depth analysis of direct targets, splicing isomer functions, and molecular mechanisms. Furthermore, current research is heavily concentrated on Arabidopsis, with relatively insufficient functional validation and breeding applications in crops such as maize and wheat. Despite substantial progress, several bottlenecks remain for translational applications in breeding, such as functional redundancy among splicing factor family members, growth penalties associated with overexpression, and tissue-specific and developmental-stage-dependent effects. To address these challenges, we discuss promising strategies, including CRISPR/Cas9-mediated splice-site editing, the use of inducible or tissue-specific promoters, and targeted modulation of upstream kinases, although extensive field trials and rigorous evaluations remain necessary. Collectively, this review provides a theoretical framework for understanding the roles of splicing factors in RNA-level regulation of plant stress adaptation and highlights their potential for breeding improvement. Full article

Salt stress severely limits plant growth, particularly in woody species. In this study, a time-course transcriptomic analysis (0–24 h NaCl treatment) revealed a clear time-dependent transcriptional reprogramming pattern in Betula platyphylla, characterized by rapid early activation followed by gradual stabilization. The response can be divided into three phases: early stress perception and signaling (1–3 h), mid-stage metabolic and hormonal reprogramming (5–9 h), and late-stage homeostasis and physiological adaptation (12–24 h). Early responses are dominated by signal transduction, the middle phase by metabolic reorganization and enhanced translation, and the late phase by redox and cellular homeostasis. Compared to the limited role of the Dehydration-Responsive Element-Binding protein (DREB) pathway, Abscisic acid (ABA) and Jasmonic acid (JA) signaling appear to play more central regulatory roles. Further analyses revealed the coordinated temporal activation of Reactive oxygen species (ROS), Salt Overly Sensitive (SOS), and ABA pathways: ROS shows an early burst followed by antioxidant activation; the SOS pathway regulates ion homeostasis via the Calcineurin B-like protein (CBL)-CBL-interacting protein kinase (CIPK) module; and ABA signaling progresses from biosynthesis to downstream transcriptional regulation. Protein interaction network analysis further identifies ABA signaling as a central hub integrating Ca²⁺ signaling, ROS metabolism, and ion transport. Overall, B. platyphylla responds to salt stress through a temporally coordinated regulatory network, providing new molecular insights into salt tolerance mechanisms in woody plants. Full article

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

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. Full article