Search Results (2,028)

Fusarium ear rot (FER), caused by Fusarium verticillioides, is a devastating disease that substantially reduces maize yield and compromises kernel quality. To investigate the genetic and molecular basis of resistance, an F₂ population derived from a cross between the resistant inbred line 3IBZ2 and the susceptible inbred line KW5G321 was analysed. By integrating bulked segregant analysis sequencing (BSA-Seq) with RNA sequencing (RNA-Seq), a major quantitative trait locus (QTL), designated qFER4, was identified on chromosome 4. Genetic analysis further demonstrated that qFER4 confers resistance through partial dominance. Transcriptome profiling of the resistant line revealed 7684 and 7906 differentially expressed genes (DEGs) at 36 and 72 h post inoculation (hpi), respectively. These DEGs were significantly enriched in defence-related biological processes and pathways, including phenylpropanoid biosynthesis, jasmonic acid signalling, MAPK cascades, and plant-pathogen interactions. By combining QTL mapping with transcriptome analyses, four candidate genes within the qFER4 interval were screened. Sequence analysis identified extensive structural variations in the promoter and coding regions of Zm00001d053393, including a premature stop codon predicted to lead to a gain-of-function mutation. In contrast, the other three genes exhibited only minor promoter polymorphisms with identical coding sequences between the parental lines. Overall, this study identifies a novel major-effect QTL and candidate gene associated with FER resistance, providing a foundation for gene function and a valuable genetic resource for breeding FER-resistant maize varieties. Full article

Methyl jasmonate (MeJA) is a defence-related phytohormone that triggers metabolic reprogramming in grapevines and modulates pathways associated with stress responses and secondary metabolism. However, the temporal organisation of leaf metabolic responses following MeJA elicitation remains insufficiently characterised. In this study, an untargeted metabolomic approach based on UPLC-QTOF-MS was applied to investigate the time-resolved metabolic response of Vitis vinifera L. cv. Tempranillo leaves following foliar application of 10 mM MeJA under controlled greenhouse conditions. Leaf samples were collected at 0, 3, 6, 18, 24, and 48 h post-treatment. After quality filtering, 2552 metabolite features were detected, of which 40 discriminant features met stringent statistical criteria (maximum fold change ≥ 2 and p ≤ 0.05). Putative annotation according to Metabolomics Standards Initiative guidelines (MSI levels 2–3) revealed modulation of several metabolite classes, including carbohydrate-derived conjugates, terpenoid-related metabolites, hydroxycinnamic acid derivatives, and flavonoid-associated compounds. Temporal profiling revealed structured and non-monotonic metabolic responses characterised by rapid early changes between 3 and 6 h, followed by delayed accumulation patterns peaking around 24 h. Early phases were mainly associated with carbohydrate-related metabolites, suggesting rapid redistribution of carbon resources after elicitor perception. These results indicate that MeJA-induced metabolic adjustment in Tempranillo leaves occurs through temporally differentiated response phases rather than a uniform metabolic shift, providing a time-resolved metabolomic framework for interpreting elicitor-driven defence responses in grapevine. Full article

The market value of fragrant rice is largely defined by the presence and intensity of its aroma, which is primarily attributed to volatile compound 2-acetyl-1-pyrroline (2-AP). The biosynthesis of 2-AP is chiefly governed by recessive alleles of the badh2 gene. Nevertheless, 2-AP accumulation is also profoundly shaped by environmental factors and agronomic management. Field practices—such as balanced nitrogen and potassium fertilization, supplementation with trace elements, and application of plant growth regulators like methyl jasmonate—promote 2-AP synthesis by increasing precursor availability and enhancing the activity of key enzymes. Additionally, tillage systems, alternate wetting and drying irrigation, optimal planting density, and harvest timing significantly affect aroma quality. Abiotic stresses, including moderate drought, salinity, optimal temperatures around 25 °C, and low light during grain filling, can also stimulate 2-AP accumulation, often through shifts in proline metabolism and activation of stress-responsive pathways involving GABA and methylglyoxal. Despite the promise of these strategies, several challenges persist, such as the common trade-off between yield and aroma intensity, complex genotype-by-environment interactions, and incomplete elucidation of the molecular mechanisms involved. Moving forward, integrating multi-omics analyses with smart agriculture technologies will be essential to unravel the regulatory networks underlying aroma formation and to advance the breeding of high-yielding fragrant rice varieties with stable aroma traits under changing climate scenarios. Full article

Jasmonic acid (JA) and its derivative, methyl jasmonate (MeJa), are naturally occurring plant hormones involved in alleviating abiotic stresses, such as exposure to extreme temperatures (cold or heat), flooding and drought. JA content increased following MeJa applications at pre- or postharvest, regulating several physiological and biochemical processes during fruit growth and ripening. As a preharvest treatment, MeJa increased crop yield and improved the organoleptic quality of the fruit. Regarding postharvest applications, MeJa reduced the chilling injury symptoms in sensitive fruits when they were stored at cold temperatures. In addition, there is some evidence of crosstalk between JA and other plant hormones. In this review, we highlight the mechanisms by which jasmonates contribute to plant stress resistance, regulating the biosynthesis and metabolism of abiotic stress and improving fruit quality. Full article

Drought stress during germination impairs seed germination and seedling development in wheat. Seed germination depends on embryo lipid mobilization for energy supply; however, the molecular mechanisms underlying lipid mobilization in drought stress germination remain unclear. Two wheat cultivars with significant differences in drought resistance, Shannong 28 (SN28) and Xinmai 296 (XM296), were subjected to integrated transcriptomic, metabolomic, and lipidomic analyses to reveal molecular response differences. SN28 exhibited increased root length (RL), while XM296 showed significant decreases in germination energy (GE), vigor index (VI), and single seedling dry weight (SSDW). Multi-omics integration revealed that SN28 maintained efficient lipid mobilization under drought through a distinctive regulatory strategy: suppressing jasmonic acid synthesis to prevent excessive growth inhibition, activating α-DOX1 signaling to maintain defense function, and coordinating these with low expression of ABA signaling factors MYB96 and ABI4 to relieve lipid mobilization suppression. Upregulated lipase and nsLTP genes (TaLTPIe.1, TaLTPIg.1) promoted lipid mobilization, while coordinated activation of arginine–proline metabolism, zeatin biosynthesis, and antioxidant defense pathways provided metabolic support. In contrast, XM296’s extensive inhibition of lipoxygenase enzymes and insufficient lipid mobilization capacity directly underlies its drought susceptibility. These findings indicate that cultivar-specific lipid metabolism patterns are key determinants of germination-stage drought resistance, providing candidate genes for wheat breeding. Full article

PYL proteins are core components of the abscisic acid (ABA) signaling pathway and are involved in plant responses to biotic and abiotic stresses. In this study, a total of 19, four, and eight PYL genes were identified in Saccharum spontaneum, the Saccharum spp. hybrid R570, and Sorghum bicolor, respectively. Phylogenetic analysis classified these PYL genes into three distinct groups. Cis-acting element analysis, Gene Ontology annotation, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment and gene expression profile indicated that members of the PYL gene family are mainly associated with hormone signaling and stress-related biological processes. The ScPYL8 gene (GenBank accession number: OR838856) was isolated from sugarcane cultivar QT3. Expression of the ScPYL8 gene was induced under stresses of cold, PEG, SA, MeJA, ABA, and brown stripe disease (Bipolaris setariae). The gene was expressed in roots, stems and leaves, with the highest expression level in leaves. Subcellular localization analysis showed that the ScPYL8 protein localized to the cytoplasm and nucleus. ScPYL8 overexpression in tobacco activated the reactive oxygen species defense system and regulated the ABA and jasmonic acid signaling pathways, enhancing its resistance against Fusarium solani var. coeruleum. These findings provide insights into the expression, function, and evolutionary characteristics of the PYL gene family in sugarcane, offering valuable genetic resources for future molecular breeding. Full article

Background: The Calcineurin B-like (CBL) and CBL-interacting protein kinase (CIPK) system constitute critical signaling modules mediating plant responses to abiotic stress. Although these families have been studied across various species, their evolutionary dynamics across grasses and the functional plasticity of specific isoforms remain elusive. Methods: A genome-wide analysis of CBL and CIPK families was conducted across five major Poaceae species (Oryza sativa, Triticum aestivum, Zea mays, Sorghum bicolor, and Saccharum spontaneum). Phylogenetic and synteny analyses were analyzed to family expansion and evolution. Cis-regulatory elements analysis in gene promoter regions were examined to predict potential stress-responsive features. Expression profiles of OsCBL and OsCIPK gene families were examined by qRT-PCR under conditions involving PEG-induced osmotic stress, pathogen strain P6 inoculation, and exogenous application of the phytohormones abscisic acid (ABA) and methyl jasmonate (MeJA). Protein–protein interactions between selected CBL (OsCBL4) and CIPK pairs were assessed via Yeast Two-Hybrid (Y2H) and Luciferase Complementation Imaging assays (LCI). Results: Phylogenetic and synteny analyses indicated that segmental duplications have contributed substantially to the expansion of these gene families. Promoter analysis revealed that the majority of CBL and CIPK family members, exemplified by OsCBL4, traditionally characterized as a salt sensor, possesses a cis-element architecture (rich in ABREs and MBS) heavily biased towards dehydration responsiveness. Expression profiling showed that OsCBL4 is significantly hyper-induced by direct osmotic stress (PEG) but exhibits almost no response to exogenous ABA. A subset of kinases genes (e.g., OsCIPK2, 9, 18) displayed PEG-induced expression patterns resembling those of OsCBL4, whereas OsCIPK30 remained transcriptionally unresponsive under the same conditions. Protein interaction assays demonstrated that OsCBL4 physically interacts exclusively with PEG-responsive transcriptionally activated kinases such as OsCIPK9, but failed to interact with the non-responsive OsCIPK30. Conclusions: Our study provides a genomic characterization of CBL and CIPK families across five major Poaceae species. The combined expression and interaction data reveal that OsCBL4-assembles with specific CIPKs into signaling modules during osmotic stress responses in rice, pointing to roles that go beyond salt stress responses. The findings establish a foundation for further functional dissection of CBL-CIPK pathway diversification in abiotic stress adaptation. Full article

Loquat (Eriobotrya japonica Lindl.) is a subtropical evergreen fruit tree that accumulates abundant bioactive triterpene compounds with diverse pharmaceutical activities. Its leaves have been used in traditional Chinese medicine for over 1000 years. Methyl jasmonate (MeJA) is a conserved elicitor that stimulates plant secondary metabolism. However, the regulatory mechanisms of terpenoid biosynthesis after MeJA treatment in loquat callus remain largely unknown. In this study, we employed an integrated targeted metabolomic and transcriptomic approach to investigate the effect of exogenous MeJA on terpenoid biosynthesis in loquat callus. In total, 131 terpenoid compounds were detected, including 112 triterpenes, six triterpene saponins, seven diterpenoids, three sesquiterpenoids and three monoterpenoids. After MeJA treatment, a total of 55 and 33 differential metabolites (DEMs) were identified at 24 h and 48 h, respectively. Most DEMs were triterpene compounds, displaying increased accumulation. Among them, ursolic acid showed the highest accumulation at 24 h, and betulinic acid was most abundant at 48 h. Meanwhile, transcriptome analysis showed significant upregulation of terpenoid biosynthesis genes, including EjFPSs, EjSQEs, EjOSC2 and EjCYP716A2, as well as genes related to jasmonic acid (JA)-mediated signaling and JA-responsive genes in loquat callus treated with MeJA. Overall, these results provide a deeper understanding of the mechanism of terpenoid accumulation in loquat callus induced by MeJA and establish a theoretical basis for utilizing plant cell culture techniques to achieve production of the valuable terpenoid metabolites that are applied in the functional food and pharmacological industries. Full article

Osmanthus fragrans, a fragrant plant native to China, is extensively utilized in the food and cosmetics industries. However, its optimal harvest period spans only 2–3 days, restricting industrial utilization. Long non-coding RNAs (lncRNAs) have emerged as key regulators of plant growth, yet their roles in O. fragrans petal opening and senescence remain unexplored. Here, we performed high-throughput sequencing of O. fragrans petals across six developmental stages, generating a valuable transcriptomic resource. We identified 57,860 mRNAs and 2414 lncRNAs, including 6499 differentially expressed mRNAs (DEMs) and 494 differentially expressed lncRNAs (DELs). Co-expression and WGCNA analyses revealed key modules associated with petal opening (Turquoise module) and senescence (Blue module). The Blue module, significantly correlated with the S6 senescence stage, contained hub lncRNAs novel_00098659 and novel_00077227 co-expressed with multiple transcription factors and hormone signaling components, including 10 ERFs, OfEIN3, OfJAZ, and OfMYC2. Transient overexpression of novel_00077227 in tobacco accelerated leaf senescence in a hormone-dependent manner, with significant increases in electrolyte leakage and MDA content, and reductions in chlorophyll content and antioxidant enzyme activities. qRT-PCR analysis confirmed that novel_00077227 alters the expression of tobacco homologs of predicted target genes involved in ethylene, auxin, jasmonate, and ABA signaling pathways. This study provides a valuable transcriptomic resource of senescence-associated lncRNAs in O. fragrans and offers evidence for the potential involvement of a key candidate, novel_00077227, in hormone-associated senescence regulation. These findings provide a foundation for future functional studies and potential applications in extending flower longevity. Full article

Bacterial fruit blotch (BFB), caused by Acidovorax citrulli (Aac), is a devastating bacterial disease to the melon industry. The scarcity of resistant germplasms has hindered in-depth research into its resistance mechanisms. In this study, we combined comparative transcriptomics, physiological assays, and hormonal profiling to explore the defense mechanisms of resistant (ZT145) and susceptible (ZT146) melon germplasms. The results indicated that resistant plants rapidly initiated a coordinated defense mechanism within 12 h after inoculation. This was characterized by an induced increase in salicylic acid (SA), activation of core immune pathways (plant–pathogen interaction, MAPK signaling pathway, etc.), and upregulation of phenylpropanoids and other biosynthetic processes. In contrast, susceptible plants exhibited a delayed and less coordinated response, characterized by SA inhibition, a surge in jasmonic acid (JA), and the broad but non-coordinated activation of multiple pathways, ultimately leading to physiological dysregulation. Through comparative analysis, we identified nine key genes that were early responders to pathogen challenge, as well as 21 genes that might be responsible for maintaining resistance. Our findings suggest that the resistance of melon to BFB is determined not by the abundance of defense-related genes but rather by the plant’s ability to rapidly activate a coordinated, SA-dominated defense network during early infection. This study provides an integrative theoretical framework for deciphering the molecular and physiological mechanisms against bacterial diseases in melon. 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

Mulberry (Morus alba) is an economically important forest tree species, yet cutting propagation is constrained by low adventitious rooting efficiency. Although ABT, a composite rooting promoter, can improve cutting survival, its molecular basis remains unclear. Here, cuttings of the cultivar Qiangsang 1 were treated with ABT, NAA, or IAA (200–1000 mg/L) and subjected to transcriptome profiling to elucidate how ABT enhances rooting. Hormone-related analyses showed that ABT upregulated GH3 (auxin-amido synthetase) at days 0 and 20, implicating auxin homeostasis. ERF1/2 (ethylene response factors) exhibited a temporal oscillation, with induction at day 10 followed by repression from days 20 to 30, consistent with a shift from developmental programs to defense-related processes. In parallel, JAZ (jasmonate ZIM-domain) genes were downregulated at day 0 and subsequently upregulated; together with CYP94C1, these changes may attenuate jasmonate-associated defense signaling. For cell remodeling and defense coordination, ABT reduced the expression of genes associated with cell-wall rigidity while inducing EXPA11 (expansin) at day 20, potentially facilitating root primordium emergence. Meanwhile, PR-1 (pathogenesis-related protein 1) was transiently upregulated at days 0, 20, and 30, and the concomitant modulation of WRKY transcription factors and RPM1 suggests enhanced defense readiness. Integrative network analysis further indicated that a GH3–ERF1/2–PR-1 module links hormonal and defense cues and may activate BAT1 (energy metabolism) and RBOHB (ROS production) to support adventitious root elongation. Collectively, these results suggest that ABT improves rooting efficiency by reshaping hormonal homeostasis and coordinating cell-wall reconstruction with a pre-activated defense state, thereby providing a conceptual framework for balancing root induction and defense responses during vegetative propagation in forest trees. Full article

Mediator is a central transcriptional coactivator that connects sequence-specific transcription factors with RNA polymerase II to control inducible gene expression in plants. MED16 is a Mediator tail module subunit that functions as a context-dependent integrator, helping coordinate developmental programs with environmental adaptation. This review summarizes current evidence for MED16 function from structural and evolutionary perspectives to physiological outputs, with emphasis on how MED16 interacts with transcription factors and other Mediator subunits to shape RNA polymerase II engagement at target loci. In terms of development, MED16 contributes to organ growth and root system architecture, and comparative studies have revealed that it plays conserved roles in lineage-specific wiring. Under abiotic stress, MED16 supports the efficient activation of stress-inducible transcription, including cold acclimation and nutrient stress responses such as phosphate starvation-dependent root remodeling. In immunity, MED16 modulates salicylic acid- and jasmonate/ethylene-associated defence outputs and can be targeted by plant viruses, which is consistent with its role in antiviral transcriptional responses. Mechanistically, MED16 participates in cooperative and competitive interactions within the Mediator complex that tune hormone-responsive outputs, exemplified by MED25-related competition in abscisic acid signalling. We highlight key limitations and future directions, including the need for mechanistic validation beyond Arabidopsis, clearer models of dosage control in crops, improved understanding of context-dependent tail configurations, and high-resolution mapping of MED16 interaction interfaces. Full article

Cherry blossom trees are iconic ornamental plants of the spring known for their vibrant colors and elegant forms. However, their short flowering period limits their ornamental value. Prunus subhirtella ‘Autumnalis’ is notable for its ability to flower a second time in autumn. Study of the secondary flowering of this variety may offer insights into the development of cherry blossoms. Here, we studied the secondary flowering of Prunus subhirtella ‘Autumnalis’ by collecting three types of flower buds: the terminal buds of long branches in autumn (LB), the basal buds of short branches in autumn (SB), and flower buds in spring (FB). Transcriptomic and metabolomic analyses were then conducted on autumn flower buds to identify key metabolic pathways associated with secondary flowering. These pathways were primarily involved in nutrient accumulation and plant hormone biosynthesis. We then quantified changes in indole-3-acetic acid (IAA), abscisic acid (ABA), jasmonic acid (JA), and gibberellic acid (GA₃), as well as levels of soluble protein, soluble sugar, and starch in flower buds. Correlation analysis indicated that IAA was necessary for flower bud development; ABA was weakly correlated with secondary flowering; and JA was significantly negatively correlated with secondary flowering. The GA₃ content was higher in LB than in SB and was significantly positively correlated with secondary flowering. Additionally, nutrient levels were higher in LB than in SB, suggesting that the accumulation of sufficient nutrients supports the second bloom. Correlation analysis revealed that ABA and GA₃ levels were positively correlated in flower buds, but GA₃ was negatively correlated with JA levels. This study provides a theoretical basis for understanding the molecular and physiological mechanisms underlying the secondary flowering phenomenon in Prunus subhirtella ‘Autumnalis’ and offers valuable insights for extending the ornamental period of cherry blossom trees. Full article

Jasmonic acid (JA) signaling plays a pivotal role in plant stress response, with Jasmonate ZIM-domain (JAZ) proteins acting as key transcriptional repressors. Quinoa (Chenopodium quinoa Willd.) is highly stress-tolerant, but its JAZ gene family remains poorly characterized. In this study, we identified 11 CqJAZ genes in the quinoa genome and systematically analyzed their phylogenetic relationships, gene structures, conserved motifs, and cis-acting elements in their promoters. Expression profiling revealed distinct response patterns of CqJAZ genes to salt, drought, and saline-alkali stresses, among which CqJAZ1 was significantly down-regulated under all three conditions. Subcellular localization analysis indicated that CqJAZ1 is localized to the nucleus. Ectopic overexpression of CqJAZ1 in Arabidopsis thaliana inhibited root growth and reduced survival rates under salt, saline-alkali, and osmotic stresses. Physiologically, CqJAZ1-overexpressing lines had elevated malondialdehyde (MDA), decreased superoxide dismutase (SOD) and peroxidase (POD) activities, and reduced endogenous JA accumulation under stress conditions. Furthermore, they showed reduced methyl jasmonate (MeJA) sensitivity. Collectively, CqJAZ1 negatively regulates quinoa stress tolerance by modulating JA homeostasis and compromising antioxidant defense capacity, shedding light on quinoa’s JA signaling and stress-resistance mechanisms. Full article