Search Results (915)

Auxin (IAA), a key natural signaling molecule, plays a pivotal role in regulating plant growth, development, and stress responses. Understanding its signal transduction mechanisms is crucial for improving crop yields. In this study, we conducted a comparative transcriptome analysis of wheat leaf and root tissues treated with different concentrations of IAA (0, 1, and 50 μM). Functional enrichment analysis revealed that differentially expressed genes (DEGs) exhibited tissue-specific regulatory patterns in response to auxin. Weighted Gene Co-expression Network Analysis (WGCNA) identified receptor-like kinase genes within the MEgreen module as highly correlated with auxin response, suggesting their involvement in both root and leaf regulation. Among them, TaPBL7-2B, a receptor-like kinase gene significantly upregulated under 50 μM IAA treatment, was selected for functional validation. Ectopic overexpression of TaPBL7-2B in Arabidopsis thaliana (Col-0) enhanced auxin sensitivity and inhibited plant growth by suppressing root development and leaf expansion. In contrast, knockout of the Arabidopsis homolog AtPBL7 reduced auxin sensitivity and promoted both root and leaf growth. Transcriptome analysis of Col-0, the TaPBL7-2B overexpression line, and the pbl7 mutant indicated that TaPBL7-2B primarily functions through the MAPK signaling pathway and plant hormone signal transduction pathway. Furthermore, qRT-PCR analysis of wheat varieties with differing auxin sensitivities confirmed a positive correlation between TaPBL7-2B expression and auxin response. In conclusion, TaPBL7-2B acts as a negative regulator of plant growth, affecting root development and leaf expansion in both Arabidopsis and wheat. These findings enhance our understanding of auxin signaling and provide new insights for optimizing crop architecture and productivity. Full article

Abiotic stress can reprogram the gametophytic pathway; the mechanisms by which floral bud pre-treatment influences microspore embryogenesis initiation remain unclear. In this study, we use bisulfite sequencing, sRNA-seq, and RNA-seq to analyze the dynamic changes in rice microspores under different cold treatment durations. Our results showed that a 10-day cold treatment is essential for CXJ microspore embryogenesis initiation. DNA methylation levels showed a slight change at CG, CHG, and CHH sites under cold treatment. The number of both hyper- and hypomethylated DMRs increased over cold treatment, with more hypermethylated DMRs at 5 and 10 dpt. Hypermethylated DMRs were more frequently in the TSS region compared to hypomethylated DMRs. The proportion of 24 nt sRNAs increased upon cold stress, with more downregulated than upregulated sRNAs at 10 dpt. The number of DMR target DEGs increased from 5 to 10 dpt. Promoter hypomethylation at the CHH site was more frequently associated with DEGs. These outcomes suggested that the RdDM pathway participates in the initiation of rice ME. GO analysis indicated that DMR target DEGs at 10 dpt were enriched in responses to chemical stimuli, biological processes, and stress responses. An auxin-related gene, OsHOX28, was further identified. Its upregulation, potentially mediated by the RdDM pathway, may play a crucial role in the initiation of rice ME. This study provides more information on epigenetic mechanisms during rice ME. Full article

Anthocyanins are important phenolic compounds in grape skins, affecting the color, oxidation resistance, and aging ability of red wine. In recent years, global warming has had a negative effect on anthocyanin biosynthesis in grape berries. Ethylene serves as a crucial phytohormone regulating the development and ripening processes of fruit; however, the specific molecular mechanism and the regulatory network between ethylene signaling and the anthocyanin biosynthesis pathway remain incompletely understood. In this study, 400 mg/L ethephon (ETH) solution was sprayed onto the surface of grape berries at the lag phase (EL-34), and the changes in anthocyanin-related genes and metabolites were explored through transcriptomic and metabolomic analysis. The results showed that ETH treatment increased Brix and pH in mature berries. In total, 35 individual anthocyanins were detected, in which 21 individual anthocyanins were enhanced by ETH treatment. However, the anthocyanin profile was not affected by exogenous ethylene. Transcriptomics analysis showed that there were a total of 825 and 1399 differentially expressed genes (DEGs) 12 h and 24 h after treatment. Moreover, key structural genes in the anthocyanin synthesis pathway were strongly induced, including VvPAL, VvCHS, VvF3H, VvF3′5′H, VvDFR and VvUFGT. At the maturity stage (EL-38), the expression levels of these genes were still higher in EHT-treated berries than in the control. ETH treatment also influenced the expression of genes related to hormone biosynthesis and signal transduction. The ethylene biosynthesis gene (VvACO), ethylene receptor genes (VvETR2, VvERS1 and VvEIN4), ABA biosynthesis gene (VvNCED2), and ABA receptor gene (VvPYL4) were up-regulated by ETH treatment, while the auxin biosynthesis gene (VvTAA3) and seven genes of the auxin-responsive protein were inhibited by exogenous ethylene. Meanwhile, ETH treatment promoted the expression of the sugar transporter gene (VvEDL16) and two sucrose synthase genes (VvSUS2 and VvSUS6). In EHT-treated berries, 19 MYB and 23 ERF genes were expressed differently compared with the control (p < 0.05). This study provides the theoretical foundation and technical support for the regulation of anthocyanin synthesis in non-climacteric fruit. Full article

As an auxin-responsive gene, Gretchen Hagen 3 (GH3) maintains hormonal homeostasis by conjugating excess auxin with amino acids in plant stress-related signaling pathways. GH3 genes have been characterized in many plant species, but the characteristics of pepper (Capsicum annuum L.) GH3 (CaGH3) gene family members in response to multiple stimulants are largely unknown. In this study, we systematically identified the CaGH3 gene family at the genome level and identified eight members on four chromosomes in pepper. CaGH3s were divided into two groups (I and III) and shared conserved motifs, domains, and gene structures. Moreover, CaGH3s had close evolutionary relationships with tomato (Solanum lycopersicum L.), and the promoters of most CaGH3 genes contained hormone and abiotic stress response elements. A protein interaction prediction analysis demonstrated that the CaGH3-3/3-6/3-7/3-8 proteins were possibly core members of the CaGH3 family interaction. In addition, qRT-PCR results showed that CaGH3 genes were differentially expressed in pepper tissues and could be induced by phytohormones (IAA, ABA, and MeJA) and abiotic stresses (salt, low temperature, and drought) with different patterns. In addition, CaGH3-5 and CaGH3-7 were cloned, and the sequences showed a high degree of conservation. Moreover, the results of subcellular localization indicated that they were located in the membrane and chloroplast. Notably, after overexpressing CaGH3-7 in tomato, RNA-seq was performed on wild-type and transgenic lines, and the differentially expressed genes were mainly enriched in response to external stimuli. This study not only lays the foundation for a comprehensive understanding of the function of the CaGH3 gene family during plant growth and stress responses but also provides potential genetic resources for pepper resistance breeding. Full article

The response of plants to elevated atmospheric [CO₂] is highly dynamic and influenced by developmental stage, yet its role in photosynthetic acclimation remains underexplored. This study examines the physiological and molecular responses of wheat (Triticum durum, var. Amilcar) to elevated [CO₂] (700 ppm vs. 400 ppm) at two distinct developmental stages: the vegetative stage at the end of the elongation stage and the reproductive stage at the beginning of ear emergence (Z39 and Z51, respectively). Wheat plants at the developmental stage Z39, cultivated under elevated [CO₂], maintained photosynthetic rates despite a carbohydrate build-up. However, at Z51, photosynthetic acclimation became more evident as the decline in Rubisco carboxylation capacity (Vc_max) persisted, but also stomatal conductance and diffusion were decreased. This was accompanied by the up-regulation of the CA1 and CA2 genes, likely as a compensatory mechanism to maintain CO₂ supply. Additionally, hormonal adjustments under elevated [CO₂], including increased auxin and bioactive cytokinins (zeatin and isopentenyl adenine), may have contributed to delayed senescence and nitrogen remobilization, sustaining carbon assimilation despite biochemical constraints. These findings highlight the developmental regulation of photosynthetic acclimation, emphasizing the need for the stage-specific assessments of crop responses to future atmospheric conditions. Full article

Konjac glucomannan (KGM), derived from Amorphophallus konjac, is increasingly utilized in food and pharmaceutical applications. However, inconsistent KGM production across cultivars jeopardizes its quality and market viability. Lanthanum (La) has been shown to promote KGM levels, but the underlying mechanism remains unclear. In this study, 20~80 mg L⁻¹ La significantly stimulated KGM accumulation compared with the control group. We performed a transcriptome analysis and found 21,047 differentially expressed genes (DEGs), predominantly enriched in carbohydrate and glycan metabolism pathways. A total of 48 DEGs were linked to KGM biosynthesis, with 20 genes (SuSy, INV1/3/5/6, HK1/2, FPK2, GPI3, PGM3, UGP2, GMPP1/4, CslA3~7, CslH2, and MSR1.2) showing significant positive correlations with KGM content. Interestingly, three key terminal pathway genes (UGP1, UGP3, and CslD3) exhibited strong upregulation (log2 fold change > 3). Seven DEGs were validated with qRT-PCR, aligning with the transcriptomic results. Furthermore, 12 hormone-responsive DEGs, including 4 ethylene-related genes (CTR1, EBF1/2, EIN3, and MPK6), 6 auxin-related genes (AUX/IAA1-3, SAUR1-2, and TIR1), and 2 gibberellin-related genes (DELLA1-2), were closely linked to KGM levels. Additionally, the transcription factors bHLH and AP2/ERF showed to be closely related to the biosynthesis of KGM. These results lay the foundation for a model wherein La (Ш) modulates KGM accumulation by coordinately regulating biosynthetic and hormonal pathways via specific transcription factors. Full article

Salt stress is a major constraint to seed germination and early seedling growth in rice, affecting crop establishment and productivity. To understand the mechanisms underlying salt tolerance, we investigated two rice varieties with contrasting responses as follows: salt-tolerant sea rice 86 (SR86) and salt-sensitive P559. Germination assays under increasing NaCl concentrations (50–300 mM) revealed that 100 mM NaCl induced clear phenotypic divergence. SR86 maintained bud growth and showed enhanced root elongation under moderate salinity, while P559 exhibited significant growth inhibition. Transcriptomic profiling of buds and roots under 100 mM NaCl identified over 3724 differentially expressed genes (DEGs), with SR86 showing greater transcriptional plasticity, particularly in roots. Gene ontology enrichment revealed tissue- and genotype-specific responses. Buds showed enrichment in photosynthesis-related and redox-regulating pathways, while roots emphasized ion transport, hormonal signaling, and oxidative stress regulation. SR86 specifically activated genes related to photosystem function, DNA repair, and transmembrane ion transport, while P559 showed activation of oxidative stress-related and abscisic acid (ABA)-regulated pathways. Hormonal profiling supported transcriptomic findings as follows: both varieties showed increased gibberellin 3 (GA3) and gibberellin 4 (GA4) levels under salt stress. SR86 showed elevated auxin (IAA) and reduced jasmonic acid (JA), whereas P559 maintained stable IAA and JA levels. Ethylene precursor and salicylic acid levels declined in both varieties. ABA levels rose slightly but not significantly. These findings suggest that SR86’s superior salt tolerance results from rapid growth, robust transcriptional reprogramming, and coordinated hormonal responses. This study offers key insights into early-stage salt stress adaptation and identifies molecular targets for improving stress resilience in rice. Full article

Plant-parasitic nematodes represent a significant threat to agriculture, causing substantial economic losses worldwide. Among the biological alternatives for their control, the genus Trichoderma has emerged as a promising solution for suppressing various nematode species. This article reviews key studies on the interaction between Trichoderma spp. and plant-parasitic nematodes, highlighting the most studied species such as Trichoderma harzianum, Trichoderma longibrachiatum, Trichoderma virens, and Trichoderma viride, mainly against the genera Meloidogyne, Pratylenchus, Globodera, and Heterodera. Trichoderma spp. act through mechanisms such as mycoparasitism, antibiosis, competition for space in the rhizosphere, production of lytic enzymes, and modulation of plant defense responses. They also produce metabolites that affect nematode mobility, reproduction, and survival, such as gliotoxin, viridin and cyclosporine A. In addition, they secrete enzymes such as chitinases, proteases, lipases, and glucanases, which degrade the cuticle of nematodes and their eggs. Furthermore, Trichoderma spp. induce systemic resistance in plants through modulation of phytohormones such as jasmonic acid, ethylene, salicylic acid and auxins. The use of Trichoderma in integrated nematode management enables its application in combination with crop rotation, organic amendments, plant extracts, and resistant varieties, thereby reducing the reliance on synthetic nematicides and promoting more sustainable and climate-resilient agriculture. Full article

Fruit shape diversity in melon is governed by complex genetic networks, with ethylene biosynthesis playing a pivotal yet poorly characterized role. In this study, we identified a rare CmACS7^{A57V/frameshift} double mutant through fine mapping of the fsq2 locus. Ethylene-mediated ovary growth regulation has been completely lost in the CmACS7^{A57V/frameshift} double mutant, driving a transition from elongated to spherical fruit. Transcriptome analysis was performed to clarify the core role of CmACS7 in the ethylene signaling pathway. The loss of CmACS7 function regulates key genes in the ethylene responsive factor, cytokinin signaling pathway, and auxin-related genes, resulting in an imbalance in hormone levels. This imbalance directly affects the coordination of cell proliferation and expansion and ultimately determines the fruit morphology. A genetic diversity analysis of public melon germplasm resources indicated that while the CmACS7^{A57V/frameshift} mutation accounts for only 0.5% of the germplasm, it is strongly correlated with the round fruit phenotype and is important for breeding in Xinjiang. The results of this study suggest that CmACS7^{A57V/frameshift} could be used as a molecular marker to accelerate the breeding of melon varieties with excellent fruit morphology and, at the same time, reveal the coevolutionary significance of this gene in the domestication of Cucurbitaceae crops. Full article

AT-hook motif nuclear-localized (AHL) genes play critical roles in chromatin remodeling and gene transcription regulation, profoundly influencing plant growth, development, and stress responses. While AHL genes have been extensively characterized in multiple plant species, their biological functions in pepper (Capsicum annuum L.) remain largely uncharacterized. In this study, we identified 45 CaAHL genes in the pepper genome through bioinformatics approaches. Comprehensive analyses were conducted to examine their chromosomal distribution, phylogenetic relationships, and the structural and functional features of their encoded proteins. Phylogenetic clustering classified the CaAHL proteins into six distinct subgroups. Transcriptome profiling revealed widespread expression of CaAHL genes across diverse tissues—including roots, stems, leaves, flowers, seeds, pericarp, placenta, and fruits—at various developmental stages. Quantitative real-time PCR further demonstrated that CaAHL1, CaAHL33, and CaAHL23 exhibited consistently high expression throughout flower bud development, whereas CaAHL36 showed preferential upregulation at early bud development stages. Expression profiling under hormone treatments and abiotic stresses indicated that CaAHL36 and CaAHL23 are auxin-inducible but are repressed by ABA, cold, heat, salt, and drought stress. Subcellular localization assays in Nicotiana benthamiana leaf epidermal cells showed that both CaAHL36 and CaAHL23 were predominantly localized in the nucleus, with faint expression also detected in the cytoplasm. Collectively, this study provides foundational insights into the CaAHL gene family, laying the groundwork for future functional investigations of these genes in pepper. Full article

NF-Y transcriptional regulators play crucial roles in diverse biological processes in plants, primarily through the formation of NF-Y complexes that bind to specific DNA motifs. These complexes modulate the expression of downstream genes, which influence plant development and growth. In our research, the function of the NF-Y family C subunit member SlNF-YC9 gene in tomato was investigated with the CRISPR/Cas9 method. In contrast to the WT (wild type), the mutant CR-SlNF-YC9 exhibited a prominent protrusion at the fruit tip. The quantitative PCR analysis displayed that the transcription levels of genes associated with auxin transport (PIN4, PIN5, and PIN9) as well as auxin response genes (ARF7 and LAX3) were enhanced in the CR-SlNF-YC9 fruits than in the WT. Analysis of dual-luciferase reporter and EMSA assays showed that the SlNF-YC9-YB13b-YA7a trimer specifically binds the FUL2 promoter and represses its expression. In conclusion, our results suggest that SlNF-YC9 is crucial in influencing tomato fruit shape by the formation of NF-Y heterotrimeric complexes. Full article

Ascorbic acid (ASC) is a furan-based lactone derived from 2-ketogluconic acid that functions as a major antioxidant and redox buffer in mature plant tissues, although its content is lower in meristematic cells. ASC is commonly considered a reactive oxygen species (ROS) scavenger; however, its role in the regulation of plant development remains unclear. Additionally, the chemical behavior of ascorbate warrants special attention during ASC supplementation in in vitro plant culture. In this study, I investigated in detail the behavior of ascorbate in plant tissue culture medium and its uptake by plants. As a secondary objective, the role of ascorbate in root growth regulation was evaluated. The effects of low ASC levels on root architecture and its interaction with auxin signaling were studied using the vtc1 and vtc2 mutants of Arabidopsis thaliana, as well as through external ascorbate supplementation. Several marker lines for auxin response/distribution were used, along with direct ascorbate measurement via HPLC. Reducing ascorbate content through mutations had no significant effect on root development or auxin signaling, whereas high-concentration ASC supplementation inhibited both auxin signaling and root development, as demonstrated using auxin response and transport markers. At the organ level, ASC supplementation significantly downregulated auxin response-mediated cell cycle activation during lateral root induction. Based on the data presented, exogenous ascorbate may regulate root development through its interaction with auxin signaling pathways. Full article

As key endogenous signal molecules regulating plant growth processes, plant hormones have significant applications in forage breeding. The experiment used ‘Elymus sibiricus Qingmu No. 2’ as the test material, and the effects of foliar applied phytohormones of gibberellin (GA₃: 50, 100, 200, and 300 mg/L), cytokinin (6-BA: 1, 10, 100, and 150 mg/L), epibrassinolide (EBR: 0.01, 0.1, 1, and 10 mg/L), zeatin (ZT: 1, 10, 20, and 100 mg/L), and auxin (IAA: 10, 50, 100, and 150 mg/L) on growth and physiological responses in Elymus sibiricus were investigated. The results indicated that GA₃ at 200 mg/L significantly enhanced biomass by 38.19%, plant height by 75.11%, and leaf area by 40.58% compared to controls. IAA (150 mg/L) specifically increased stem diameter by 38.25%, while 6-BA (100 mg/L) elevated chlorophyll content and antioxidant enzyme activities, indicating dual photoprotective and stress-mitigating roles. EBR (1 mg/L) and ZT (20 mg/L) moderately enhanced growth metrics. All treatments universally boosted stress tolerance via soluble sugar/protein accumulation and antioxidant system activation. Through comprehensive analysis, we recommend GA₃ (200 mg/L) for effective grassland improvement, propose synergistic combinations of 6-BA and IAA to overcome morphological limitations, and highlight ultra-low EBR (0.01–0.1 mg/L) as a priority for future research. Full article

Root zone restriction (RZR) technology optimizes plant growth and quality. However, the fleshy root system of Paeonia ostii exhibits sensitivity to spatial constraints, and research on the plasticity of its root architecture and adaptation mechanisms remains inadequate. This study provides a functional analysis of biomass allocation and root architectural responses to the root-zone restriction (RZR) in P. ostii, comparing three container volumes (8.5, 17, and 34 L). While the total biomass increased with root zone volume (e.g., shoot biomass rose from 9.30 g to 59.94 g), RZR induced a 44.8% increase in root-to-shoot ratio, indicating carbon reallocation to enhance belowground resource acquisition. The principal component analysis identified root biomass, volume, and surface area as key plasticity drivers. Optimal root efficiency occurred at 26.09–28.23 L, where root length and tip/fork numbers peaked. Mechanistically, RZR elevated superoxide dismutase (SOD) activity by 49.74% but reduced catalase (CAT) by 74.24%, disrupting H₂O₂ homeostasis. Concurrently, auxin transporter genes (PIN1, AUX1) were upregulated, promoting root elongation and lateral branching through auxin redistribution. We hypothesize that ROS–auxin crosstalk mediates architectural reconfiguration to mitigate spatial stress, with thickened roots enhancing structural stability in restricted environments. The study underscores the need to optimize root zone volume in woody species cultivation, providing thresholds (e.g., >28 L for mature plants) to balance biomass yield and physiological costs in horticultural management. Full article

Global climate change has led to an increased frequency of extreme weather events, with flooding caused by heavy rainfall posing a significant threat to plant growth and survival. Styrax japonicus, a species of ecological and economic importance, exhibits stronger flooding tolerance compared to its congener Styrax tonkinensis. Endogenous hormonal systems in plants are indispensable for integrating growth dynamics, developmental transitions, and ecological stress perception-transduction pathways. To investigate the response of S. japonicus to flooding stress at both hormonal and molecular levels, this study utilized annual seedlings of S. japonicus as experimental material. Two levels of flooding stress, waterlogging and submergence, were applied to examine the variations in endogenous hormone levels in S. japonicus roots under different stress conditions and durations. Combined with transcriptome sequencing, critical genes associated with hormone-mediated signaling and biosynthetic processes were identified. The results showed that the content of the ethylene precursor ACC exhibited a trend of “increase–decrease–increase”, with an earlier decline under submergence compared to waterlogging stress by approximately 10 days. Abscisic acid content sharply decreased at 5 d, followed by an initial increase and subsequent decrease, with higher ABA levels observed under waterlogging stress than under submergence. GA content significantly decreased after 10 d in both stress conditions. KEGG enrichment analysis revealed that the most prominently enriched pathway for DEGs was plant hormone signal transduction under both waterlogging and submergence stress, with 314 and 370 DEGs identified, respectively. Analysis of common genes indicated their association with ethylene, ABA, auxin, and BRs. After further investigation of DEGs in the ethylene and ABA biosynthesis process, we identified key enzyme genes encoding ACS, ACO, and NCED, which are critical for their biosynthesis. Full article