Search Results (123)

Since the first plant gene essential for arbuscular mycorrhizal (AM) symbiosis was identified, more than 170 such genes have been discovered. However, these findings remain scattered across species, and a systematic synthesis is urgently needed to guide future functional studies and breeding applications. This review provides a systematic classification and contextual overview of the currently reported plant genes essential for AM symbiosis, covering leguminous species (e.g., Medicago truncatula, Lotus japonicus) and non-leguminous species (e.g., Oryza sativa, Solanum lycopersicum). We classify these genes into functional modules corresponding to key stages of AM symbiosis: SL-mediated pre-symbiotic signaling, chitin signal perception, activation of the common symbiosis signaling pathway (CSSP), calcium (Ca²⁺) oscillation generation, arbuscule development and maintenance, and nutrient exchange. Beyond classification, we highlight conserved genetic modules across plant lineages and discuss their implications for engineering AM symbiosis in non-host or poorly symbiotic crops. This synthesis establishes a foundational genetic resource for molecular breeding aimed at enhancing nutrient-use efficiency and sustainable crop production. Full article

Plants are constantly exposed to diverse abiotic stresses, including drought, salinity, and extreme temperatures, which severely limit growth, development, and crop productivity. These stresses disrupt physiological, biochemical, and molecular processes, leading to reduced photosynthesis, altered water and ion homeostasis, and accumulation of reactive oxygen species (ROS). Plants have evolved sophisticated sensing and signaling mechanisms to perceive these stresses, with phytohormones playing central roles in mediating adaptive responses. Key hormones, including abscisic acid (ABA), salicylic acid (SA), jasmonates (JAs), gibberellins (GAs), auxin (IAA), ethylene (ET), melatonin, and strigolactones (SLs), regulate stress tolerance by controlling stomatal behavior, root architecture, antioxidant systems, osmolyte accumulation, and stress-responsive gene expression. Importantly, these hormones operate within an intricate network of crosstalk, integrating multiple signaling pathways to balance growth and stress adaptation. Interactions among ABA, GA, JA, SA, auxin, ET, SLs, and melatonin enable plants to coordinate transcriptional regulation, protein phosphorylation, and ROS signaling, optimizing survival under fluctuating environmental conditions. Understanding the molecular mechanisms underlying hormonal crosstalk and their roles in abiotic stress tolerance provides valuable insights for developing resilient crops in the face of climate change. Full article

SMXL proteins serve as central regulators of strigolactone (SL) and karrikin (KAR) signaling pathways, orchestrating key developmental processes including shoot branching, floral transition, photomorphogenesis and stress responses. However, the SMXL gene family has not been systematically characterized in Lavandula angustifolia. We identified 37 LaSMXL genes in the lavender genome. Phylogenetic and synteny analyses classified these proteins into four subgroups (Groups I–IV) and indicated that family expansion in lavender was mainly driven by whole-genome and segmental duplications, with most duplicated pairs evolving under strong purifying selection. Gene structure and motif analyses revealed high conservation within each subgroup. Promoter cis-element analysis suggested that LaSMXL genes are integrated into light-, hormone- and stress-responsive regulatory networks. RNA-seq profiling showed that most LaSMXL genes are weakly expressed, but a small subset displays pronounced tissue specificity and clear transcriptional responses to low temperature. Protein–protein interaction predictions and co-expression network analysis further placed highly expressed LaSMXLs within conserved SL/KAR and chloroplast/light-associated modules, alongside D14, KAI2, MAX2, CCD7/CCD8, and CYP711A. Together, these findings provide the first comprehensive overview of the SMXL gene family in lavender and identify candidate LaSMXL genes for future functional studies aimed at optimizing plant architecture and inflorescence-derived essential oil biosynthesis. Full article

Plant hormones and their synthetic analogueues offer sustainable alternatives for crop protection, yet the direct antifungal activity of strigolactone (SL) and its analogues against necrotrophic pathogens remain largely unexplored. Here, we screened eight phytohormones and related analogues for treatments of Botrytis cinerea and identified the SL analogue rac-GR24 (racemic GR24) as a concentration-dependent growth inhibitor active at low micromolar concentrations. Given the stereochemical complexity of SLs and their analogues, we evaluated multiple enantiopure isomers and found that ent-5DS and GR24^ent-5DS, which differ in configuration from natural SLs, exhibited the strongest inhibitory activity. This stereospecific response was further validated using another filamentous fungus, Sclerotinia sclerotiorum, which displayed an identical susceptibility profile. Combinatorial treatments with enantiopure isomers and double-concentration rac-GR24 revealed that the antifungal effect of the racemate is primarily attributable to the GR24^ent-5DS enantiomer, whereas the opposite enantiomer GR24^5DS is almost inactive. Collectively, our findings uncover a stereospecific response in fungal pathogens, demonstrating that B. cinerea and S. sclerotiorum respond to exogenous SL analogues in a chirally selective manner. This work establishes a stereochemically defined framework for developing enantioselective fungicidal agents with potential applications in sustainable agriculture. Full article

Adventitious root (AR) formation is essential for the vegetative propagation of woody plants, yet recalcitrant species within Castanea spp. exhibit strong genotype-dependent differences in rooting ability. Strigolactones (SLs) and auxins are key phytohormones regulating AR development, but their dynamic interplay remains poorly understood. We analysed three Castanea genotypes with contrasting rooting capacities—two hybrids, Castanea crenata × Castanea sativa (‘Maraval’ and ‘Marsol’), and one native accession, Castanea sativa (‘Kozjak’)—to investigate temporal changes in auxin and SL content following severance. Cuttings were sampled at multiple time points from 0 min to 3 weeks prior to visible root formation, and again at 12 weeks, when rooting outcomes were assessed. Individual tissues were analysed for active auxins, conjugated and oxidised auxin metabolites, and strigolactones. From these data, total auxin content (TAC), total auxin-related compounds (TCC), total strigolactone content (TSC), and the ratios TAC:TCC and TAC:TSC were calculated. Rooting success differed markedly among genotypes: ‘Maraval’ and ‘Marsol’ rooted successfully (75–79%), whereas ‘Kozjak’ failed to produce roots and instead formed extensive callus. Hormonal profiling indicated that rooting competence depends not only on auxin levels but also on the dynamic balance between active auxins, inactive metabolites, and strigolactones. ‘Kozjak’ showed an early predominance of free IAA and elevated SL levels, correlating with inhibited AR initiation, whereas the hybrid genotypes maintained more stable hormonal ratios, which supported successful rooting. These results highlight the importance of coordinated hormonal balance rather than absolute hormone concentrations in regulating AR formation. Our study provides new insights into hormone dynamics underlying rooting recalcitrance in chestnut and suggests potential strategies to improve clonal propagation of woody species. 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

Miscanthus lutarioriparius exhibits strong potential for cadmium (Cd) accumulation, making it a promising candidate for the phytoremediation of Cd-contaminated soils. However, its full remediation potential remains underexploited, highlighting the need for targeted genetic improvement This study presents a comprehensive genome-wide identification and systematic characterization of 20 Ml4CL (4-coumarate: CoA ligase genes) in the M. lutarioriparius. Results indicate that the Ml4CL gene family has undergone substantial evolutionary divergence and expansion. Phylogenetic classification is highly consistent with gene structures ad conserved motifs suggesting potential functional diversification. Promoter analysis revealed a complex cis-regulatory landscape enriched in n ABA- and light-responsive elements, frequently co-occuring with hormone-responsive elements associated with jasmonic acid (JA), gibberellins (GAs), salicylic acid (SA), and strigolactones (SLs) signaling. This pattern suggests that the Ml4CL family may function as an integrative regulatory node linking multiple stress and hormonal signaling pathways. Importantly, under Cd stress, Ml4CL genes exhibited diverse expression dynamics, including gene-specific repression and dose-dependent biphasic responses. Notably, Ml4CL4 showed strong repression, while other members displayed “induction-then-repression” or “repression-then-induction” patterns, suggesting a staged or hierarichical transcriptional response. These findings further suggest that Cd-responsive signaling networks may involve non-linear or threshold-dependent mechanismsthat activate distinct transcriptional programs depending on stress levels. Collectively, this study highlights the regulatory role of the Ml4CL family in plant adaptation to complex environments and identifies candidate dose-resonsive regulatory elements and key allelic variations. These findings provide valuable targets for molecular breeding and synthetic biology aimed at improving crop stress resilience. Full article

Perennial ryegrass is a widely cultivated cool-season forage and turf grass species whose growth and development are limited by drought and high temperature. MAX2 is an F-box leucine-rich repeat (LRR) protein, which serves as a central component of strigolactone (SL) and karrikin (KAR) signaling pathways, involved in multiple growth and developmental processes as well as stress response. Here, we identified LpMAX2, a perennial ryegrass (Lolium perenne L.) homolog of Arabidopsis MAX2 (AtMAX2) and rice D3. LpMAX2 can interact with AtD14 and LpD14 in an SL-dependent manner, implying functional conservation with AtMAX2. Overexpression of LpMAX2 in the Arabidopsis max2-3 mutant partially rescued leaf morphology, hypocotyl elongation, and branching phenotypes, while fully restoring drought tolerance, highlighting the evolutionarily conserved roles of MAX2 in plant growth and drought resistance. In conclusion, LpMAX2 is evolutionarily conserved in SL/KAR signaling pathways, highlighting its potential function in drought adaptation. In addition to elucidating the biological function of LpMAX2, this study identifies a promising genetic target for enhancing stress resilience in forage grasses through biotechnological approaches. Full article

Texture is a critical quality attribute of strawberry fruit, and phytohormones play a pivotal role in fruit softening, which mainly results from cell wall metabolism, which is governed by genes and enzymes. To gain further insights into strawberry (Fragaria × ananassa, Duch. cv.  Akihime ) softening, our study investigated changes across five stages in fruits in their firmness, soluble solids content (SSC), cell microstructure, cell wall materials, activities of cell wall-modifying enzymes, gene expression, endogenous phytohormone levels, and their correlation. During strawberry ripening, firmness decreased, while SSC, intercellular space, and separation of the cell wall from the plasma membrane increased. Meanwhile, the contents of ionic pectin (ISP) and cellulose (CE), pectin methylesterase (PME) activity, FaPME expression, and the levels of zeatin (Z) and strigolactone (SL) decreased, showing a positive correlation with firmness. In contrast, the activities of pectate lyase (PL) and cellulase (Cx), the expression of FaPL and FaCx, and the contents of gibberellin A₄ (GA₄), GA₉, and abscisic acid (ABA) increased during ripening, and these were negatively correlated with firmness. These results suggest that Z and SL are associated with the maintenance of cell wall integrity and firmness, whereas increases in GA₄, GA_9, and ABA are linked to enhanced cell wall disassembly and fruit softening. Full article

Piriformospora indica, a broad-spectrum plant growth-promoting fungus, has been successfully applied in blueberry (Vaccinium corymbosum L.). In this study, through an integrated transcriptomic and biochemical analyses, we investigated the effects of P. indica colonization on blueberry root growth under long-term tap water (EC ≈ 1500 μs/cm) irrigation. Comparative transcriptomic analysis revealed that P. indica colonization greatly influenced the expression of genes involved in RNA biosynthesis, solute transport, response to external stimuli, phytohormone action, carbohydrate metabolism, cell wall organization, and secondary metabolism pathways. Consistently, the fungal colonization significantly improved the nutrient absorption ability, and increased the contents of sucrose, starch, trehalose, total phenolic, total flavonoids, and indole-3-acetic acid (IAA), while suppressing the accumulations of jasmonic acid (JA), abscisic acid (ABA), 1-aminocyclopropane-1-carboxylic acid (ACC), and strigolactone (SL) in blueberry roots. Quantitative real-time PCR verification also confirmed the fungal influences on genes associated with these pathways/parameters, such as auxin homoeostasis-associated WAT1, cell wall metabolism-related EXP, phenylpropanoid biosynthesis-related PAL and CHS, carotenoid degradation-related CCD8, transportation-related CNGC, trehalose metabolism-related TPP, and so on. Our study demonstrated that P. indica improved blueberry adaptability to mild salt stress by synergistically regulating cell wall metabolism, secondary metabolism, stress responses, hormone homeostasis, sugar and mineral element transportation, and so on. Full article

The coordinated development of stems and branches, together with optimal strip spacing, is crucial for improving soybean yield in the soybean–maize relay strip intercropping system. Shading during the seedling stage often causes excessive stem elongation and reduced branching; however, the physiological mechanisms underlying stem–branch responses to changing light environments remain unclear. This study aimed to clarify how early-stage shading and subsequent light recovery regulate stem and branch development through changes in canopy light environment, phytohormones, and the expression of related genes. Shade-tolerant Nandou12 and shade-sensitive Nannong99-6 were used as experimental soybean cultivars. Six treatments were implemented: a non-shaded control with uniform strip spacing (T0: 40 cm); seedling shading (40% PAR-transmission nets for 35 days after emergence) combined with variable strip spacing (T1: 40 cm; T2: 70 cm; T3: 100 cm; T4: 130 cm; T5: 160 cm). Canopy light environment, main stem and branch traits, photosynthetic characteristics, phytohormones, related gene expression, and yield components were measured. The results indicated that shade at the seedling stage significantly upregulated auxin (IAA) biosynthesis gene GmYUCC and downregulated phytochrome gene GmPhyB in the main stem tips, corresponding to increased IAA and cytokinins (CKs). In branch tips, shading significantly downregulated GmYUCC and GmPhyB while upregulated GmMAX3B, which is consistent with reduced levels of IAA, CKs, and brassinosteroid (BR), and increased strigolactones (SLs). After light recovery, GmPhyB and GmYUCC were upregulated whereas GmMAX3B was downregulated, accompanied by higher IAA, GA, CKs, and BRs, lower SLs, and improved chlorophyll content, Rubisco content, photosynthesis, and the accumulation of soluble sugar and starch in branches. Nandou12 achieved up to 10% higher yield under shading, and a 100 cm strip spacing maintained 74–111% yield of the non-shaded soybean. These findings demonstrate that cultivars with strong shade tolerance and high branching potential, combined with a 100-cm strip spacing, effectively sustain yield in relay-intercropped soybean by enabling favorable physiological responses to early shading and subsequent light recovery. Full article

Jasmonates (JAs) are crucial phytohormones governing plant growth and defense against stresses. This review synthesizes the intricate molecular mechanisms underlying JA crosstalk with key hormones: auxin (AU), gibberellin (GA), abscisic acid (ABA), ethylene (ET), brassinosteroids (BRs), strigolactones (SLs), and salicylic acid (SA). We focus on interactions during development and stress adaptation, highlighting how these range from synergistic (e.g., JA-ABA/ET in defense, JA-AU in root growth) to antagonistic (e.g., JA-SA in pathogen response, JA-GA/BRs in growth processes). Central to this crosstalk are key regulatory nodes like the MYC2 transcription factor and JAZ repressor proteins, which integrate signals through transcription factor networks, targeted protein degradation, and post-translational modifications. By elucidating these molecular pathways, our review establishes a framework for understanding the complex regulatory logic of hormone interactions. Furthermore, it offers insights for the strategic engineering of hormone signaling (e.g., modulating JAZ stability or MYC2 activity) to enhance crop resilience to environmental challenges. Full article

Abiotic stresses, such as heat, cold, drought, and salt, pose severe challenges to global agriculture, with climate change exacerbating these threats and intensifying risks to crop productivity and food security. Strigolactones (SLs), a class of phytohormones, play pivotal roles in mediating plant development and enhancing stress resilience. This review highlights the multifaceted mechanisms through which SLs regulate plant responses to abiotic stresses, integrating molecular, physiological, biochemical, and morphological dimensions. Molecularly, SLs regulate the expression of stress-responsive genes, such as those encoding antioxidant enzymes and mitogen-activated protein kinase (MAPK), to enhance plant acclimation and survival under abiotic stress conditions. Moreover, genes involved in SL biosynthesis and signaling pathways are indispensable in these processes. Physiologically and biochemically, SLs improve resilience by modulating photosynthesis, stomatal closure, reactive oxygen species (ROS) metabolism, and osmotic adjustment. Morphologically, SLs modulate leaf morphology, shoot development, and root architecture, enhancing plant stress tolerance. Collectively, SLs emerge as key regulators of plant tolerance to abiotic stresses, offering promising strategies for advancing crop improvement and securing agricultural sustainability in the face of climate change. Full article

Bisphenol A (BPA) is a widely used chemical to produce raw materials in plastic production, which has led to its ubiquity in the natural environment and toxicity to both plants and humans. In this study, we evaluated the phytotoxic effects of BPA on the growth and physiology of pepper (Capsicum annuum L.), a globally cultivated horticultural plant. Our high-performance liquid chromatography (HPLC) result revealed that 0.5 mg/kg of BPA treatment did not lead to the accumulation of BPA in the leaves and fruits of pepper plants. The exogenous application of 5 mg/kg of BPA prominently inhibited pepper growth, while 0.5 mg/kg of BPA had no obvious effects on pepper growth. Additionally, our transcriptomic assay revealed that BPA-regulated gene expression is associated with photosynthesis and reactive oxygen species (ROS) signaling. Physiological and qRT-PCR assays further demonstrated that BPA reduced chlorophyll content and increased ROS levels by regulating the expression of genes related to chlorophyll synthesis and ROS production. Our transcriptomic data also elucidated the potential role of plant hormones, including brassinolides (BR), salicylic acid (SA), jasmonic acid (JA), and strigolactone (SL) in mediating BPA-induced phytotoxicity. Furthermore, BPA activated the N⁶-methyladenosine (m⁶A) modification to exert its toxicity. Collectively, our findings offer additional insights into the mechanisms through which BPA attenuates pepper plant growth, which might contribute new knowledge toward a better scientific assessment of BPA exposure risks in horticultural species. Full article

The root parasitic weed Phelipanche aegyptiaca (Pers.) Pomel poses a serious threat to solanaceous crops, leading to yield losses of up to 80% in tomato (Solanum lycopersicum L.). Strigolactones (SLs), derived from the carotenoid metabolic pathway, serve as key host-recognition signals for root-parasitic plants. This study investigated the molecular mechanisms of host resistance, focusing on the suppression of SL biosynthesis through altered carotenoid metabolism in the high-pigment tomato mutants hp-1 and og^c. Both pot experiment and in vitro seed germination assays demonstrated that the mutants exhibited reduced susceptibility to P. aegyptiaca and triggered lower germination rates in broomrape seeds compared to the wild-type cultivar AC. Quantitative RT-PCR analysis revealed a significant downregulation of SL biosynthesis genes (SlD27, SlCCD7, SlCCD8, SlMAX1, SlP450, SlDI4) in hp-1 at various parasitic stages post-inoculation, with a more pronounced suppression observed in hp-1 than in og^c. Notably, the extent of downregulation correlated with the enhanced resistance phenotype in hp-1. These findings highlight a synergistic resistance mechanism involving the coordinated regulation of carotenoid metabolism and SL biosynthesis, providing new insights into the molecular defense network underlying tomato-broomrape interactions. Full article