Search Results (2,636)

Salt stress poses a major environmental challenge that leads to ecological imbalance and reduced agricultural productivity globally. Sapium sebiferum, a highly valued ornamental and perennial woody oil species, shows promise for saline land utilization due to its natural salt stress adaptability. However, the underlying mechanisms remain largely unexplored. This study investigated the responses of S. sebiferum to salt stress by integrating RNA sequencing and Non-invasive Micro-test Technology (NMT). Comparative transcriptome analysis identified 693, 1061, and 1851 differentially expressed genes at 1 h, 3 h and 6 h after salt treatment, respectively. Functional analysis of DEGs revealed that genes related to ion binding, transmembrane transport, and signal transduction were significantly enriched. Notably, genes involved in calcium (Ca²⁺) and phytohormone signaling were altered, activating stress-response pathways. Furthermore, the dynamic effects of salt stress on nitrate (NO₃⁻) and ammonium (NH₄⁺) uptake were assessed. After salinity stress (150 mM NaCl), an increase in the net influx of NO₃⁻ was observed under the conditions of the assay, while the net flux of NH₄⁺ did not show a significant change. The differential expression of NRT genes suggests that NO₃⁻ may play a multifaceted role in salinity tolerance, potentially contributing to nutrition, ion homeostasis, and signaling pathways. The coordinated signaling network likely allows S. sebiferum to effectively cope with salinity stress and sustain physiological functions under challenging conditions. These findings provide valuable insights into the molecular basis of salt tolerance in S. sebiferum, thereby supporting sustainable practices in saline environments. Full article

Acibenzolar-S-methyl (ASM), a salicylic acid (SA) analog, and jasmonic acid (JA) are chemical inducers of plant defenses, yet crosstalk between SA- and JA-associated pathways may result in antagonistic outcomes. Here, we assessed how ASM and JA, applied alone or in combination, are associated with rice blast severity and defense-related responses in an upland rice cultivar. Plants of rice (Oryza sativa L., cv. Primavera) were treated with JA, ASM or JA + ASM and subsequently challenged with Magnaporthe oryzae. ASM treatment was associated with reduced leaf blast severity (LBS), whereas JA treatment was associated with increased LBS. Antagonistic outcomes were observed in the combined treatment: LBS in JA + ASM plants was higher than in ASM-treated plants but lower than in JA-treated plants. Lipoxygenase (LOX) activity was induced by JA and positively correlated with LBS, indicating that higher LOX activity aligned with greater susceptibility under the tested conditions. In contrast, ASM-treated plants showed higher peroxidase (POX) activity, which was associated with lower LBS. Disease outcomes were also linked to secondary defense metabolism and phenylpropanoid-related components, including phenylalanine ammonia-lyase (PAL), salicylic acid (SA) and phenolic compounds (PC). Overall, these results provide an integrated biochemical profile of how ASM, JA and their combination are associated with contrasting blast outcomes in upland rice, consistent with antagonistic interactions between JA- and SA-associated defense responses. These findings may inform the use of defense inducers and the interpretation of defense markers in upland rice systems where blast management is a major constraint. Full article

Municipal wastewater represents an underutilized secondary biomass resource rich in organic carbon and nutrients that can be valorized through biotechnological conversion. In this study, we developed an integrated multi-microbial biorefinery platform to transform municipal wastewater into value-added biofuel via sequential bacterial treatment, microalgal biomass generation, and fungal-assisted harvesting. Wastewater was first pretreated with Bacillus subtilis to enzymatically hydrolyze complex organic substrates and enrich the medium with bioactive metabolites, including auxins and gibberellins. The conditioned wastewater was subsequently used to cultivate Chlorella vulgaris, followed by biomass recovery using Trichoderma viride pellets as a sustainable bioflocculant. The integrated consortium significantly enhanced nutrient removal efficiency and promoted algal biomass accumulation, lipid enrichment, and biodiesel productivity compared to monoculture controls. Elevated hydrolytic enzyme activities (cellulase, protease, and amylases) facilitated organic matter conversion into bioavailable substrates, while increased phytohormone levels stimulated algal growth and lipid biosynthesis. Additionally, fungal bioflocculation substantially improved biomass recovery efficiency, reducing the need for energy-intensive harvesting technologies. This work highlights the potential of a biotechnology-driven approach for integrating wastewater remediation with biofuel production. By integrating microbial metabolism, enzymatic transformation, and sustainable separation processes, the proposed biorefinery system suggests a potentially low-carbon approach for simultaneous environmental remediation and biomass valorization, although further life cycle and energy balance analyses are required to validate this aspect. Full article

Plant metabolism is essential for coordinating growth, development, and defense under changing environmental conditions. Plants continuously adjust their metabolic pathways to balance resource allocation between growth and immune responses. Under stress, metabolic reprogramming redirects energy and resources toward the production of defense compounds and activation of immune signaling pathways. These changes involve complex interactions among primary metabolism, specialised metabolites, and regulatory networks, including calcium signaling, reactive oxygen species, and phytohormones. Advances in metabolomics and multi-omics technologies have improved understanding of the metabolic control of plant immunity; however, knowledge remains fragmented, and an integrated framework linking metabolism, development, and defense is still emerging. This review examines plant immunometabolism by highlighting the dynamic relationships between metabolic networks and immune functions during development and stress. It discusses pathways that influence growth, stress-induced metabolic shifts linked to defense, and how signaling interacts with metabolism. Progress in metabolomics, transcriptomics, proteomics, and computational modeling that supports systems-level analysis of plant metabolism is also summarized. In addition, potential applications in agriculture and biotechnology, including metabolic engineering, genome editing, and metabolomics-based breeding, are considered in relation to crop resilience. By integrating metabolism, signaling, and systems biology, this review provides a broad perspective on how metabolic reprogramming shapes the growth–defense trade-off in plants and outlines future directions for developing climate-resilient crops. Full article

Background: Tartary buckwheat (Fagopyrum tataricum) serves as an excellent model for studying plant water adaptation mechanisms due to its exceptional drought tolerance. While aquaporins (AQPs) mediate the transmembrane transport of water and solutes in plants, their fine-tuned regulatory networks underlying stress resilience in Tartary buckwheat remain largely elusive. Methods: Here, we combined bioinformatics and transcriptomics to systematically identify 30 highly conserved FtAQP genes at the genome-wide level. Results: Cross-validated by qRT-PCR, our analysis revealed their distinct expression patterns across different organs. Based on our transcriptomic data, we hypothesize that FtAQP family members potentially participate in a coordinated whole-plant water management network through differential spatiotemporal expression. Specifically, the robust transcription of FtAQP8, FtAQP12, and FtAQP28 in roots is associated with the initial water uptake process. As water undergoes long-distance transport, the synergistic upregulation of FtAQP13, FtAQP17, FtAQP20, and FtAQP29 in the stem suggests a potential role in facilitating critical lateral water flow. Furthermore, during reproductive development, FtAQP27 exhibits extreme tissue specificity in floral organs, implying its possible involvement in maintaining local osmotic homeostasis. Furthermore, the promoter regions of FtAQPs are highly enriched with cis-acting elements responsive to light, abscisic acid (ABA), and cold stress, suggesting they are intimately regulated by a coupling of endogenous phytohormones and environmental cues. Conclusions: Ultimately, this study provides valuable insights into the potential molecular basis of multidimensional water regulation in Tartary buckwheat, and identifies candidate genetic targets for improving water use efficiency in dryland agriculture through the precise manipulation of aquaporins. Collectively, while these observational findings provide valuable predictive models, future in vivo experimental validations are required to confirm their exact biological functions. Full article

Hydroponic cultivation is expanding rapidly as a resource-efficient alternative to soil-based farming, but challenges related to nutrient management, abiotic or biotic stresses, and organic production still limit the system’s performance and efficiency. Biostimulants are increasingly being explored as a promising strategy to support productivity and sustainability in soilless systems. This review summarizes the current evidence on the use of plant biostimulants to support crop performance in hydroponic systems. Microbial biostimulants, such as plant growth promoting rhizobacteria, Arbuscular Mycorrhizal Fungi, and Trichoderma spp., have been reported to promote root growth by synthesizing phytohormones, enhance nutrient uptake, and reduce the impacts of salt and heat stress, with reported improvements in biomass and nutrient use efficiency. Seaweed extracts and protein hydrolysates modulate plant hormonal balance, improve antioxidant defense, and have been associated with improvements in yield and quality. Humic and fulvic acids increase micronutrient bioavailability through chelation and stimulate root activity through auxin-like effects. In organic hydroponics, biostimulants may help address the nutrient gap by accelerating organic matter mineralization. Existing key challenges include the lack of hydroponic-specific dosage guidelines and high commercialization costs. Future efforts should further evaluate system-specific strategies, including emerging tools such as artificial intelligence-optimized strategies and the use of clustered regularly interspaced short palindromic repeats-edited microbes to support the long-term sustainability of controlled environment agriculture. Full article

Abscisic acid (ABA) regulates diverse aspects of plant growth and secondary metabolism, yet its concentration-dependent effects on rhizomatous spice crops remain poorly understood at the systems level. Here, we investigated the phenotypic, physiological, hormonal, and multi-omics responses of ginger (Zingiber officinale) to foliar-applied ABA across a concentration gradient. Exogenous ABA modulated ginger growth in a distinctly non-linear manner. Low-to-moderate concentrations (5–15 mg/L) significantly enhanced aboveground branching and belowground rhizome yield, whereas high concentration (35 mg/L) inhibited branching while promoting structural carbohydrate accumulation, revealing a concentration-dependent trade-off between growth and secondary wall deposition. Hormone profiling uncovered global reprogramming of the endogenous hormonal network, with optimal ABA (15 mg/L) coordinately elevating growth-promoting hormones and defense-related signals, while high concentrations suppressed multiple hormone pathways and triggered negative feedback inhibition of endogenous ABA biosynthesis. Integrated metabolomic and transcriptomic analyses identified convergent enrichment on phenylpropanoid biosynthesis, gingerol biosynthesis, and plant hormone signal transduction. Co-expression network analysis revealed a highly interconnected module of 583 genes linking hormone signaling to secondary metabolism, with coordinated up-regulation of key enzymes from phenylalanine ammonia-lyase (PAL) to polyketide synthase under 15 mg/L ABA explaining the 64% increase in 6-gingerol content. This study establishes a mechanistic chain from ABA perception to improved ginger yield and quality, mediated by hormonal crosstalk and transcriptional activation of the phenylpropanoid-gingerol network. We propose an “ABA optimization window” of 5–15 mg/L for precision cultivation of high-quality ginger, providing a systems-level framework for understanding hormone-mediated regulation of secondary metabolism in medicinal and spice crops. Full article

The sucrose synthase (SUS) gene family plays a pivotal role in plant carbon metabolism, growth, and development. In this study, we identified 65 SUS genes across six Brassica species (B. rapa, B. nigra, B. oleracea, B. juncea, B. napus, and B. carinata), and systematically analyzed their structural characteristics, evolutionary history, and expression profiles. Phylogenetic analysis classified these genes into three subfamilies (SUSI, SUSII, and SUSIII). SUS4 orthologs (from SUSI subfamily) are completely lost in Brassica, and total SUS gene numbers are just 6–7 in Brassica diploid species, though the SUSIII subfamily exhibits significant expansion in Brassica polyploid species. Selection pressure analysis (Ka/Ks) revealed that the Brassica SUS family has primarily undergone purifying selection, although certain members show evidence of adaptive evolution. Comprehensive expression profiling and qRT-PCR validation demonstrated the functional diversification of BnSUS genes in tissue specificity and responses to hormonal and abiotic stimuli. SUSI genes BnSUS1-1/2/3/4 are predominantly expressed in vegetative tissues and flowers; SUSII genes BnSUS2-1/2 and BnSUS3-1/2 are reproductive-organ-specific, while SUSIII genes BnSUS5-1/2 and BnSUS6-1/2/3/4 show young-plant-specific weak expression. BnSUS family genes are generally upregulated by ABA, TZ and GA but downregulated by IAA, ACC, BL and JA. Salt, drought, freezing and cold mainly upregulate the BnSUS family, heat downregulates it, and osmotic stress exerts both effects. Correspondingly, Brassica SUS promoters are enriched with light-responsive (G-box, Box-4), hormone-responsive (ABRE, CGTCA-motif) and anaerobic-induction (ARE) elements. Functional characterization demonstrated that the ABA-responsive gene BnSUS3-2 significantly improved tolerance to osmotic and ionic stresses by promoting root growth in transgenic A. thaliana seedlings. These findings underscore the essential roles of BnSUS genes in maintaining cellular homeostasis and provide a theoretical foundation for the genetic improvement of carbon metabolism and stress resilience in Brassica crops. Full article

Abscisic acid (ABA) is a major phytohormone regulating plant growth and stress responses. Subclass III SnRK2 kinases and clade A type 2C protein phosphatases (PP2Cs) are core components of ABA signaling. Despite advances from phosphoproteomics, major gaps remain, particularly in mapping PP2C dephosphorylation targets and SnRK2-dependent phosphorylation dynamics under non-stress conditions. Here, we performed large-scale LC–MS/MS phosphoproteomic analyses using the subclass III SnRK2 triple mutant srk2dei and the constitutively active PP2C mutant abi1–1C, with and without ABA treatment in Arabidopsis thaliana. We identified 2757 and 2886 differentially regulated phosphopeptides in srk2dei and abi1–1C, respectively. Beyond known ABA signaling components, these datasets revealed numerous previously uncharacterized candidate proteins involved in metabolism, membrane transport, transcription, and cytoskeletal regulation. Integrative analysis uncovered a core set of candidate proteins oppositely regulated by SnRK2-mediated phosphorylation and ABI1-mediated dephosphorylation, defining a coordinated hierarchical network. These results indicate that the SnRK2–PP2C module functions not only in stress-induced ABA responses but also as a central regulator of phosphorylation homeostasis under basal conditions. This study provides a systematic framework for the global SnRK2–PP2C phosphorylation network and reframes ABA signaling as a dynamic homeostatic system. Full article

The homeodomain-leucine zipper (HD-Zip) transcription factor family is conserved in land plants and is critical for regulating growth, development, and stress responses. Flax (Linum usitatissimum L.) is an economically valuable dual-purpose crop valued for its high nutrition and notable drought tolerance; however, its HD-Zip gene family has not been systematically characterized. In this study, a comprehensive genome-wide analysis was performed to identify and characterize the HD-Zip family in flax. A total of 34 LuHD-Zip genes were identified, which were unevenly distributed across 15 chromosomes and exhibited substantial variation in physicochemical properties. The encoded proteins ranged from 200 to 372 amino acids in length, with molecular weights of 22.7–40.3 kDa and theoretical isoelectric points (pI) of 4.49–9.46. All LuHD-Zip proteins were predicted to be hydrophilic and localized to the nucleus. Phylogenetic analysis divided these proteins into two major subfamilies (Group 1 and Group 2), a classification strongly supported by conserved gene structures and motif compositions, implying potential functional redundancy within each group. Gene duplication analysis revealed that segmental duplication events (29 pairs) were the primary drivers of family expansion. Comparative syntenic analysis further indicated that the LuHD-Zip gene family has remained relatively conserved throughout evolution. Promoter cis-element analysis identified multiple regulatory elements associated with hormone signaling and abiotic stress responses, suggesting complex transcriptional control in response to environmental stimuli. Expression profiling via quantitative real-time PCR (qRT-PCR) demonstrated that LuHD-Zip genes exhibit tissue-specific expression patterns and are differentially regulated by various phytohormone treatments and abiotic stresses. This study provides the first genome-wide characterization of the HD-Zip gene family in flax, offering valuable insights into its evolution and potential functions. These findings establish a solid foundation for future functional investigations of the LuHD-Zip gene family. Full article

Background/Objectives: Ludisia discolor, an endangered medicinal orchid, is a vital source of bioactive flavonoids which requires in vitro tissue culture for propagation and metabolite production. While light quality influences metabolic processes, the mechanisms connecting light conditions, phytohormone signaling, and flavonoid biosynthesis remain unclear. This study investigates how specific light qualities trigger secondary metabolism to improve tissue culture and conservation strategies. Methods: L. discolor was cultivated under strictly regulated LED environments (blue, red, yellow, and green). An integrated multi-omics approach, combining transcriptomic sequencing and targeted metabolomic profiling, was employed to analyze leaves, correlating plant hormone changes with flavonoid metabolite levels. Results: LED light qualities significantly altered flavonoid and phytohormone profiles, yielding 80 unique flavonoids. Blue and red light effectively promoted flavonoid accumulation, whereas yellow light suppressed it. Transcriptomics, validated by qRT-PCR, revealed distinct expression patterns in key structural genes (e.g., 4CL, PAL, CYP73A, FLS, CCoAOMT, C12RT1). Ten transcription factors (including MYB93, bZIP36, bHLH4, and bZIP44) with hormone-responsive cis-elements were co-expressed with 16 structural genes. Notably, blue light induced reactive oxygen species (ROS) signaling, activating phytohormone production (IAA, GA, ABA). These hormones subsequently stimulated transcription factors, increasing the biosynthesis of compounds like neohesperidin and hesperetin. Conclusions: We propose a novel regulatory model where light-induced ROS and phytohormone cascades activate specific transcription factors, enhancing structural gene expression in the flavonoid pathway. These findings elucidate the molecular mechanisms of light-driven secondary metabolism, providing valuable insights for the sustainable agriculture and ex situ conservation of endangered medicinal orchids. Full article

Larix olgensis, a keystone timber species in Northeast China, is increasingly threatened by Neofusicoccum laricinum-induced shoot blight, a devastating disease that compromises forest health and necessitates sustainable management strategies. Here, we demonstrate that the endophytic bacterium Bacillus amyloliquefaciens JL54 elicits multifaceted defense responses in L. olgensis, enhancing resistance to pathogen infection. Greenhouse assays revealed that JL54 pretreatment reduced disease incidence by 12.5% and achieved 43.75% control efficacy while maintaining host vigor. Histochemical analyses identified JL54-induced rapid hydrogen peroxide (H₂O₂) accumulation, extensive lignin deposition, and localized programmed cell death (PCD), indicative of a primed immune response. Transcriptomic analyses uncovered distinct temporal defense patterns: early-stage responses (0 h post-inoculation) were characterized by upregulation of cutin, suberin, and wax biosynthesis pathways, reinforcing physical barriers, whereas late-stage responses (12 h post-inoculation) were dominated by ribosome- and proteostasis-related pathways (e.g., heat shock proteins [HSPs], glutathione S-transferases [GSTs]) to mitigate cellular damage. Biochemical assays corroborated these findings, with JL54 colonization reducing membrane lipid peroxidation (27.2% decrease in malondialdehyde content) and significantly elevating the activity of key defense enzymes, including peroxidase (POD), phenylalanine ammonia-lyase (PAL), and GST. Phytohormone profiling implicated jasmonic acid (JA) as the central mediator of induced systemic resistance (ISR), with JL54-potentiated JA signaling preceding pathogen containment. Collectively, these results demonstrate that JL54 contributes to a coordinated defense strategy in L. olgensis, integrating structural reinforcement (cuticle/lignin), oxidative stress management, and JA-mediated immune priming. These insights advance the understanding of endophyte-conferred resistance in conifers and highlight JL54’s potential as a biocontrol agent for sustainable forestry. Full article

Salicylic acid (SA) is a key endogenous regulator involved in plant defense responses to biotic and abiotic stresses. The increasing resistance of pathogens to chemical plant protection products and growing environmental restrictions have intensified the search for alternative strategies to enhance plant health and stress tolerance. Among these strategies, the induction of natural defense mechanisms, in which SA plays a central signaling role, has gained particular attention. This review summarizes current knowledge on the role of SA in shaping plant resistance to environmental factors. The fundamental mechanisms of plant defense, including innate immunity, induced systemic resistance (ISR), and systemic acquired resistance (SAR), are discussed, with emphasis on the signaling function of SA and its interaction with other phytohormones, especially jasmonic acid and ethylene. The role of SA in regulating physiological processes associated with stress tolerance, such as antioxidant system activity, photosynthesis, plant growth, and senescence, is highlighted. The review of research results indicates that appropriately selected doses and timing of SA treatments can enhance resistance to selected pathogens and improve plant tolerance to adverse environmental conditions. However, treatment effectiveness depends on multiple factors, particularly SA concentration and plant–pathogen interactions. Salicylic acid is a promising component of integrated and sustainable plant protection strategies. Further research, especially under field conditions, is necessary to optimize its practical use and fully determine its potential in modern agriculture. Full article

NAC (NAM, ATAF1/2 and CUC2) transcription factors constitute one of the largest plant-specific transcription factor families and play pivotal roles in plant growth, development, and responses to environmental stresses. Systematic characterization of NAC genes is essential for understanding regulatory networks underlying key agronomic and adaptive traits. As a conservation-priority woody species with distinctive biological and horticultural value, Sinojackia xylocarpa Hu lacks comprehensive knowledge of its NAC repertoire, and elucidating its NAC family will facilitate functional studies related to development and environmental adaptation. Based on whole-genome data of S. xylocarpa, we conducted a systematic survey and characterization of the NAC transcription factor family. In total, 115 SxyNAC genes encoding the conserved NAC domain were identified, and their loci were unevenly distributed across 12 chromosomes. Analyses of gene-duplication modes and collinearity indicated that whole-genome/segmental duplication events were the major driving force for the expansion of this family. Phylogenetic relationships, gene structures, and conserved motifs classified the SxyNAC members into 15 subfamilies, revealing a highly conserved N-terminal NAC domain and a markedly diversified C-terminal regulatory region with pronounced member- and lineage-specific differences. Promoter cis-element prediction showed extensive enrichment of light-responsive, phytohormone-responsive, and stress-related elements, suggesting that SxyNAC genes may participate in coordinated regulation of multiple environmental cues and endogenous hormone pathways. Transcriptome data from six fruit developmental stages, together with qRT-PCR validation of ten representative genes, demonstrated diverse temporal and tissue-specific expression patterns during fruit development and close associations with fruit growth regulation. Overall, our findings establish a framework for exploring the evolutionary trajectories and functional diversification of NAC genes in S. xylocarpa, and they offer a valuable resource for NAC-family research and conservation-focused functional genomics in other rare or threatened plant species. Full article

Hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase, a key acyltransferase in the phenylpropanoid pathway and a canonical member of the BAHD acyltransferase family (BAHD), catalyzes the formation of pivotal intermediates in the biosynthesis of secondary metabolites such as lignin, chlorogenic acid, and flavonoids. These compounds serve indispensable protective functions in terrestrial plants, underpinning their adaptive responses to abiotic stresses such as drought, ultraviolet (UV) radiation, and oxidative damage. Although the role of HCT/HQT in the core phenylpropanoid pathway has been extensively characterized, its precise functional contributions to the flavonoid biosynthetic branch—particularly with respect to substrate selectivity, kinetic regulation, and metabolic channeling—remain incompletely understood. This review systematically analyzes the structural features, spatial conformation, catalytic mechanism, and substrate promiscuity of HCT/HQT to clarify its molecular determinants of activity and specificity. Furthermore, it highlights regulatory factors influencing HCT/HQT gene expression, such as transcription factors (MYB, bHLH, WRKY), phytohormones (GA₃, Eth, MeJA, 6-BA, MT), and abiotic/biotic stressors (temperature, blue light, nitric oxide, nano-selenium). Collectively, these insights illuminate how plants dynamically fine-tune phenylpropanoid metabolism in coordination with developmental programs and environmental challenges. This work provides a foundation for further research on HCT/HQT and supports efforts to develop improved crop varieties through targeted regulation of this central metabolic node. Full article