Search Results (986)

Phytohormones, or plant hormones, are intrinsic organic compounds within plants. These compounds have a significant impact as essential plant growth and development regulators, influencing processes from seed germination to fruit ripening. The exogenous application of these phytohormones, such as gibberellic acid (GA₃), indole-3-acetic acid (IAA), and brassinosteroids, has been shown to significantly enhance horticultural productivity, with reported increases in germination, growth, and yield ranging from 10–40%. These signaling molecules are also vital for micro and macroalgae development and functioning. Recognizing their presence within algae presents a fresh perspective for horticultural researchers and cultivators, offering opportunities to enhance the quality and application of horticultural crops. Nevertheless, the challenge arises from the presence of phytohormones in trace amounts, complicating their extraction and identification. This paper will offer a comprehensive overview of phytohormone classification and detection methods and highlight their presence in algae, which may serve as an alternative for promoting plant growth in agriculture. 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

In recent years, plant stress biology has moved beyond single-pathway descriptions toward an integrated framework in which stress perception, hormonal control, and gene regulation are tightly interconnected. Early events such as membrane-associated sensing, calcium influx, reactive oxygen species (ROS) generation, and kinase activation converge with phytohormonal networks to shape context-dependent responses. Within this framework, abscisic acid, salicylic acid, jasmonates, ethylene, auxin, cytokinins, gibberellins, brassinosteroids, and strigolactones function not as isolated regulators but as components of a dynamic signaling matrix that balances survival, defense, growth restraint, and recovery. These hormonal signals are ultimately translated into adaptive outcomes through extensive transcriptional and post-transcriptional reprogramming mediated by transcription factors, RNA-based regulators, chromatin remodeling, and stress memory mechanisms. This review synthesizes current understanding of how plants integrate stress perception, phytohormonal crosstalk, and transcriptional regulation to establish stress tolerance. We first examine the molecular basis of stress sensing and early signaling. We then discuss the central functions of major phytohormones and the logic of hormone–hormone interaction networks in coordinating stress adaptation. Next, we analyze transcriptional, post-transcriptional, and epigenetic mechanisms that determine response specificity, intensity, and persistence. We further highlight points of convergence between abiotic and biotic stress responses and discuss how combined stresses challenge traditional single-stress models. Finally, we consider the roles of omics, systems biology, and translational technologies in decoding and engineering stress-resilient phenotypes. By integrating these perspectives, this review presents plant stress tolerance as a multilevel systems property and outlines key priorities for future research aimed at developing climate-resilient crops. Full article

Banana productivity is severely limited by drought, yet the molecular basis of drought adaptation and endophyte-mediated stress alleviation remains poorly understood. Here, we performed a genome-wide analysis of the SQUAMOSA promoter-binding protein-like (SPL) transcription factor family in Musa acuminata and examined their transcriptional responses to drought stress and Serendipita indica inoculation. We identified 38 MaSPL genes, all encoding proteins with the conserved SBP domain and predicted nuclear localization. Phylogenetic, motif, gene structure, and collinearity analyses indicated that MaSPL genes are evolutionarily conserved, unevenly distributed across chromosomes, and expanded primarily through segmental duplication under purifying selection. Promoter analysis showed several cis-acting elements and transcription factor binding sites related to light, phytohormone, and stress signaling. Ten MaSPL genes were predicted as putative targets of miR156. qRT-PCR analysis showed that drought stress markedly downregulated the tested MaSPL genes, whereas miR156a expression increased, supporting an inverse regulatory relationship. Under drought, S. indica inoculation enhanced expression of most tested MaSPLs, restoring transcript accumulation while reducing miR156a to near-basal levels. Notable responses were observed in members of the MaSPL2, MaSPL9, and MaSPL13, respectively. S. indica improves drought tolerance by enhancing antioxidant defenses, reducing oxidative stress, and preserving photosynthetic and osmotic stability. Taken together, our results demonstrate that S. indica confers drought resilience in banana by counteracting drought-induced repression of MaSPL genes via the miR156–SPL module and by strengthening key physiological defense mechanisms. Full article

Jacalin-related lectins play crucial roles in plant adaptation to abiotic and biotic stresses. The rice genome encodes four putative jacalin-related lectin kinase genes (OsJacLKs), but their functions toward environmental stresses remain largely uncharacterized. This study demonstrates that a putative jacalin-related lectin kinase, OsJacLK1, conferred resistance to the rice blast fungus Magnaporthe oryzae rather than salt stress. OsJacLK1 protein exhibited agglutination activities and affinity toward chitin, fungal cell wall, and mannose. OsJacLK1 was transcriptionally activated by stress-related phytohormones salicylic acid (SA), methyl jasmonate (MeJA), abscisic acid (ABA), and indoleacetic acid (IAA), as well as salinity, chitin, and M. oryzae inoculation, suggesting its involvement in broad stress-responsive signaling pathways. Overexpression of OsJacLK1 in rice led to reduced susceptibility to rice blast disease, whereas loss-of-function osjaclk1 lines showed no significant phenotypic difference from wild-type plants upon infection. Enhanced resistance in OsJacLK1-overexpressing lines was associated with a stronger reactive oxygen species (ROS) burst and elevated hydrogen peroxide accumulation, accompanied by the up-regulation of defense-related genes (OsRac1, OsSGT1, OsMAPK6, OsPAL1, OsNAC4, OsPBZ1, OsAOS2, and OsJAZ8). Collectively, our findings establish that OsJacLK1 acts as a positive regulator of rice immunity against M. oryzae, modulating the cellular redox state, highlighting its potential as a candidate for genetic improvement of disease resistance in rice. Full article

Autophagy is a conserved degradation pathway essential for cellular homeostasis in plants. Selective autophagy confers cargo specificity through receptors, among which NEIGHBOR OF BRCA1 GENE1 (NBR1) is one of the best-characterized. NBR1 mediates the selective turnover of ubiquitinated or stress-damaged cargoes, including protein aggregates and damaged organelles, by linking them to ATG8-decorated autophagosomes via its AIM and UBA domains. This process supports proteostasis, plant development, and adaptation to abiotic stresses, including heat, drought, chilling, salinity, and heavy metals, as well as biotic stresses from bacteria, fungi, viruses, and oomycetes. In this review, we summarize current advances in understanding NBR1 structure, evolutionary conservation, and cargo recognition mechanisms, and highlight its interplay with phytohormone signaling and the ubiquitin–proteasome system (UPS) in shaping plant growth and stress resilience. Full article

Cotton, as a globally significant economic crop, is intricately regulated in its growth and development by the key genes for SA (Salicylic acid) biosynthesis. In the present study, a systematic analysis of genes related to SA biosynthesis was conducted across four cotton species, leading to the identification of 70 genes. Specifically, the tetraploid species Gossypium hirsutum and G. barbadense were found to harbor 22 and 23 genes, respectively, representing a substantial expansion compared to the 12 and 13 genes identified in the diploid progenitors G. arboreum and G. raimondii. Comprehensive characterization of chromosomal localization, phylogeny, domain architecture, and promoter cis-elements revealed a uniform distribution of key genes involved in SA biosynthesis across A/D sub-genomes of tetraploids with extensive interspecific collinearity; whole-genome and segmental duplication act as the dominant drivers for the expansion of this gene family, while partial gene loss following polyploidization results in non-doubled gene copy numbers in tetraploids relative to diploids, which reflects the evolutionary selection for genomic dosage balance. The key genes for SA biosynthesis demonstrate a high degree of conservation in protein sequences, protein structures, and conserved motifs, which constitute the structural basis for the stable maintenance of their core functions in the SA biosynthesis pathway during plant evolution. This is closely related to their core function in the salicylic acid (SA) synthesis pathway and serves as the structural basis for the stable maintenance of gene functions during evolution. Analysis of cis-elements revealed that the expression of key genes involved in SA biosynthesis is governed by a complex interplay of phytohormones, stress signals, and transcription factors. Yeast one-hybrid (Y1H) assays confirmed the interaction between the GhPAL and GhICS gene and predicted candidate transcription factors, specifically the binding of GhWRKY21 to GhICS2-1 promoter and GhMYB12 to GhPAL1-2 promoter, thus elucidating their stage-specific regulatory mechanisms in cotton fiber development and reflecting their evolution. This study provides a fundamental basis for investigating the role of the SA signaling pathway in cotton development and offers support for cotton molecular breeding. Full article

Nitrogen is a critical macronutrient for plants, playing a central role in the synthesis of proteins, amino acids, and nucleic acids. To enhance nitrogen use efficiency (NUE) and ensure sustainable agricultural production, identification of nitrogen-efficient genes and application of molecular breeding techniques are crucial for developing high-NUE rice germplasm. The nitrogen signaling pathway exhibits close crosstalk with phytohormones, including auxins (IAA), gibberellins (GAs), abscisic acid (ABA), cytokinins (CTKs), brassinosteroids (BRs), and strigolactones (SLs). This review systematically summarizes the molecular mechanisms underlying crosstalk between nitrogen and phytohormones, focusing on the physiological and molecular basis underlying their synergistic regulation of root development and NUE in rice, and outlines challenges for the complicated research field and prospective directions in future. Full article

Plants in agricultural systems rarely face single stressors; instead, they encounter concurrent biotic (pathogen, pests) and abiotic (drought, salinity, heavy metals) stresses that causes severely reduce crop yields and endanger food security. The traditional methods of breeding, genetic engineering, and agrochemicals tend to target individual stresses and still do not suffice in the complex field conditions. Compared to these approaches, nanotechnology offers distinct advantages: nanoparticles (NPs) can be applied as foliar sprays or seed treatments without lengthy breeding cycles or regulatory hurdles associated with genetically modified organisms. However, nanotechnology is not inherently “better” but rather complementary to crop engineering; each approach has specific strengths. Breeding and genetic engineering provide heritable, long-term solutions, while nanotechnology offers immediate, season-specific, and reversible interventions. Cross-tolerance, the phenomenon whereby exposure to one stress enhances tolerance to another, offers a promising alternative. This review critically examines how NPs act as stress-priming agents that induce cross-tolerance by activating overlapping defense networks, including antioxidant systems (SOD, CAT, APX), phytohormonal crosstalk (ABA, SA, JA), osmolyte homeostasis, and stress-responsive gene expression. We synthesize current evidence on NP uptake, translocation, and cellular interactions, and evaluate their dual role in directly suppressing pathogens while simultaneously enhancing plant immune responses and physiological resilience. However, efficacy is highly dose-dependent: low, subtoxic doses prime defense through hermetic ROS signaling, whereas supraoptimal doses cause phytotoxicity. The current challenges in nano-mediated stress alleviation include: (i) a persistent laboratory-to-field translation gap, with field outcomes averaging only 60–70% of greenhouse efficacy; (ii) dose-dependent phytotoxicity; (iii) poor reproducibility across studies; (iv) scalability and formulation stability issues; and (v) insufficient understanding of long-term environmental fate, including soil accumulation, non-target organism effects, and food chain safety. Future research should consider field-validated formulations (e.g., SiNPs, ZnONPs, Fe₃O₄NPs) across major staple crops); integrating nanotechnology with precision agriculture through nanosensors, remote sensing, and artificial intelligence for site-specific, dose-optimized applications;developing smart, biodegradable nanoparticles with stimuli-responsive release; and establishing harmonized regulatory frameworks for nano-agrochemical approval. When deployed responsibly, nanoparticle-induced cross-tolerance represents a sustainable approach to improve crop resistance against multifactorial stress, with significant implications for climate-resilient agriculture and global food security. Full article

Pathogenesis-related protein 1 (PR1) plays important roles in plant responses to both biotic and abiotic stresses; however, its role in mediating defense against pine wood nematode in Pinus massoniana remains unclear. In this study, a total of 63 PR1 family members were identified in P. massoniana using bioinformatics approaches and were named PmPR1-1 to PmPR1-63 based on their phylogenetic relationships. Phylogenetic analysis showed that these members were distributed among four of the six subfamilies. Most of the encoded proteins were hydrophilic, with lengths ranging from 131 to 406 amino acids. Their promoter regions contained multiple cis-acting elements associated with phytohormone signaling and stress responses, and some members formed gene clusters on chromosomes 2, 5, and 9. qRT-PCR (quantitative reverse transcription polymerase chain reaction) analysis showed that the clustered genes PmPR1-46, PmPR1-55, PmPR1-56, and PmPR1-61 were significantly upregulated in the early stage of pine wood nematode inoculation in both resistant and susceptible P. massoniana plants, with higher expression levels in resistant plants. Transient overexpression of PmPR1-61 increased SOD and PPO activities as well as proline content while decreasing CAT activity. These results suggest that the PmPR1 family may be involved in the defense response of P. massoniana against pine wood nematode. Among them, PmPR1-55, PmPR1-56, and PmPR1-61 represent candidate resistance genes worthy of further investigation and provide valuable gene resources for elucidating resistance mechanisms and supporting molecular breeding in P. massoniana. Full article

Seed germination is a critical initial stage of the plant life cycle, regulated by signaling pathways such as phytohormones and reactive oxygen species (ROS). However, the low germination rate of immature grains is a key bottleneck limiting wheat speed breeding. This study used immature grains of the winter wheat cultivar Kenong 199 (KN199) collected 18 days post anthesis to establish an efficient germination protocol. By screening individual and combined treatments of hydrogen peroxide (H₂O₂, 1%), gibberellin (GA₃, 20 μM), and varying concentrations of abscisic acid (ABA) synthesis inhibitor sodium tungstate (Na₂WO₄), alongside transcriptome analysis, we identified the optimal reagent combination and gained preliminary insight into its molecular basis. The triple reagent combination of 0.5 mM Na₂WO₄ + 20 μM GA₃ + 1% H₂O₂ exhibited the highest germination rate of 80%, approximately sevenfold higher than single reagent treatments, with germination rate peaking after 4 days. Transcriptome profiling revealed that this combination modulated the expression of key genes related to dormancy release and germination, including upregulation of GA biosynthesis gene GA3ox2 and ABA catabolism gene TaCYP707A2, and downregulation of ABA biosynthesis and signaling genes (ABI5, TaNCED1, etc.). Additionally, genes associated with energy metabolism and transport pathways were enhanced. This optimized reagent combination significantly improves immature grain germination, shortens the breeding cycle, and provides a practical tool for achieving “five generations per year” speed breeding in winter wheat. Our findings contribute to seed biology by offering a chemical strategy to overcome dormancy in immature cereal grains. Full article

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

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

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