Plant Physiology最新文献

{"title":"Distinct root apoplastic barrier distribution and conserved peroxidase function in desert trees.","authors":"Jose Gonzalez Kise, Ting Ting Xiao, Xinjing Xu, Siarhei Laptenok, Luca Genchi, Xianrong Guo, Christian G Canlas, Carlo Liberale, Ikram Blilou","doi":"10.1093/plphys/kiag760","DOIUrl":"https://doi.org/10.1093/plphys/kiag760","url":null,"abstract":"<p><p>The formation of extracellular barriers in roots plays a critical role in maintaining water balance and nutrient homeostasis; however, their molecular composition and physiological roles in desert-adapted plants remain largely unexplored. Here, we examine apoplastic barrier formation in the roots of two arid-adapted, ecologically and economically important tree species: date palm (Phoenix dactylifera) and grey mangrove (Avicennia marina). In date palm, lignin and suberin showed complementary distribution patterns within the outer root layers. In mangrove roots, lignin accumulated in the epidermis and exodermis, whereas suberin was concentrated in the exodermis. Label-free Raman spectroscopy imaging confirmed these spatial patterns. Noninvasive Magnetic resonance imaging (MRI) revealed that water distribution mirrored barrier localization: date palms retained water in the vasculature and outer tissues, whereas mangroves concentrated water in the xylem. Transcriptome analysis identified a type III PEROXIDASE (PER) highly expressed in the exodermis of both species. The PER protein localized to Golgi-derived vesicles and the plasma membrane and interacted with a component of the Golgi apparatus. Expression of date palm and mangrove PER in Arabidopsis thaliana leads to ectopic lignin deposition in the root epidermis. Together, our findings suggest that type III PEROXIDASES are transported to the plasma membrane through the Golgi vesicles and promote lignin deposition. Overall, this study reveals distinct root barrier distribution and identifies a conserved molecular component underlying structural adaptations that enable plants to thrive in challenging environments.</p>","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":8.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149183739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"OsGSK2-OsBSK3 feedback loop controls rice BR signaling","authors":"Xiaojie Tian, Wei Zhang, Linli Fu, Xinchen Wang, Chunxiao Chen, Xin Jin, Qingyun Bu","doi":"10.1093/plphys/kiag767","DOIUrl":"https://doi.org/10.1093/plphys/kiag767","url":null,"abstract":"Brassinosteroids (BRs) are essential plant hormones that regulate growth and development, including leaf angle regulation and grain size determination. Maintaining appropriate BR signaling requires precise coordination between pathway activation and attenuation. BR signaling is initiated by OsBRI1 activation, which triggers a phosphorylation cascade that ultimately inhibits OsGSK2 kinase activity, releasing OsBZR1 from repression and activating downstream responses. However, whether additional regulatory mechanisms fine-tune BR signaling remains unclear. Here, we identify OsBSK3 as a direct substrate of OsGSK2 and uncover a phosphorylation-dependent feedback mechanism within the BR signaling pathway. OsGSK2-mediated phosphorylation enhances the interactions of OsBSK3 with OsBRI1, OsGSK2, and OsPPKL1 while attenuating the regulatory activity of OsBSK3. Genetic analyses revealed that overexpression of wild-type OsBSK3 or the phosphorylation-deficient variant OsBSK3SA enhances BR responses and fully rescues the leaf angle and grain size defects of the osbsk3 mutant, whereas the phosphomimetic variant OsBSK3SD fails to restore these phenotypes. Together, our findings establish a phosphorylation-dependent OsGSK2-OsBSK3 negative feedback mechanism that fine-tunes BR signaling homeostasis in rice.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"26 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149187914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification photosynthesis-related genes in peanut (Arachis hypogaea L.) by hyperspectral phenomics, GWAS and RNA-seq.","authors":"Jiangtao Tan, Shiyuan Liu, Huaiyuan Fu, Zhongfa Zhang, Baixiang Wang, Zhi Pan, Tingting Chen, Lei Zhang","doi":"10.1093/plphys/kiag753","DOIUrl":"https://doi.org/10.1093/plphys/kiag753","url":null,"abstract":"<p><p>Peanut (Arachis hypogaea L.) contributes importantly to the global food supply, and its yield potential is closely linked to leaf photosynthetic efficiency. However, conventional measurement of leaf net-photosynthetic-rate (Leaf Pn) is time- and labor-intensive, limiting its application to large breeding populations. We established a phenomics-driven framework integrating hyperspectral reflectance and genome-wide association studies for high-throughput evaluation and genetic dissection of Leaf Pn. Machine-learning models were trained on preprocessed spectral data from 1,200 leaf samples collected in four environments. Random forest performed best after Savitzky-Golay (S-G) smoothing and first-derivative transformation (R2 = 0.81, root mean square error [RMSE] = 1.50), outperforming the vegetation index-based model (R2 = 0.66). Applying this model to a panel of 173 peanut genotypes identified two quantitative trait loci, qPn5.1 and qPn13.1, encompassing seven candidate genes. Integrated analyses prioritized Arahy.K5L3ZW, which encodes protein kinase 2B. Silencing this gene increased Leaf Pn, whereas transient overexpression decreased it, indicating that Arahy.K5L3ZW negatively regulates Leaf Pn. This framework enables high-throughput genetic dissection of seedling photosynthetic capacity and identifies a candidate target for improving photosynthetic efficiency in peanut.</p>","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":8.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149183737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coordination of lignin and pectin remodeling by a NAC transcription factor regulates seed abscission in sesame (Sesamum indicum L.).","authors":"Eunsoo Lee, Jinsu Lee, Sungup Kim, Jeongeun Lee, Minsoo Han, Woo-Taek Jeon, Minsu Park, Myoung Hee Lee, Jungin Kim, Sangwoo Kim, Yeon Ju An, Eunyoung Oh, Min Young Kim, Jeongdong Lee, Chanseok Shin, Yuree Lee, Kwang-Soo Cho","doi":"10.1093/plphys/kiag762","DOIUrl":"https://doi.org/10.1093/plphys/kiag762","url":null,"abstract":"<p><p>Seed shattering, which facilitates seed dispersal, is essential for plant reproduction but causes substantial yield loss in sesame (Sesamum indicum L.). It occurs through capsule dehiscence and/or seed abscission from the placenta, either simultaneously or independently depending on the species. In this study, we investigated cell wall-associated factors underlying delayed seed abscission in the sesame cultivar Suwon195 (SW195) relative to the easy-shattering cultivar IT030100. Histological and transcriptome analyses indicated that cell wall remodeling, particularly involving pectin and lignin, contributes to the delayed abscission phenotype of SW195. SW195 showed higher pectin methylesterase activity and stronger accumulation of low-methyl-esterified homogalacturonan, together with lower polygalacturonase-associated pectin turnover, than IT030100. These changes are consistent with a pectin-remodeling state that favors wall stabilization in the SW195 abscission zone (AZ). AZ lignification was also weaker in SW195. Pharmacological inhibition of lignin biosynthesis altered pectin staining and reduced seed abscission in IT030100, whereas monolignol supplementation restored both phenotypes, supporting a functional association between lignification, pectin-related wall remodeling, and abscission. QTL mapping and whole-genome resequencing identified a major locus on chromosome 9 encompassing a NAC transcription factor (SiNAC; SIN_1025412) and a pectin methylesterase inhibitor (SiPMEI; SIN_1025380). Transient overexpression of SiNAC enhanced lignin biosynthesis in sesame. Together, these findings indicate that coordinated lignin deposition and pectin remodeling are associated with seed abscission in sesame and identify candidate genetic components for breeding reduced-shattering cultivars.</p>","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":8.2,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149183677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lysine biosynthesis integrates carbon availability and energy homeostasis under fluctuating CO2","authors":"Débora Gonçalves Gouveia, Samantha Flachbart, Wesley E B Barrios, Philipp Westhoff, Laia S Broncano, Auxiliadora O Martins, Florencia P Coronel, Elina Welchen, Daniel H Gonzalez, Alisdair R Fernie, Adriano Nunes-Nesi, Andreas P M Weber, Wagner L Araújo","doi":"10.1093/plphys/kiag765","DOIUrl":"https://doi.org/10.1093/plphys/kiag765","url":null,"abstract":"Lysine metabolism connects amino acid biosynthesis with mitochondrial respiration through coordinated synthesis and degradation pathways that interface with the tricarboxylic acid (TCA) cycle and the mitochondrial electron transport chain (mETC). The critical role of this pathway is underscored by the embryonic lethality of the Arabidopsis L,L-diaminopimelate aminotransferase mutant (dapat), which is defective in a key step of lysine biosynthesis. Hypomorphic dapat mutant plants exhibit profound metabolic reprogramming and a constitutive energy-limited phenotype under non-stress conditions, suggesting that lysine biosynthesis contributes to basal metabolic homeostasis. We therefore hypothesized that impaired lysine biosynthesis restricts metabolic flexibility, but that changes in CO2 availability may partially compensate through carbon and nitrogen remodeling. To test this, we performed comprehensive metabolite profiling of wild-type and dapat mutant plants under low-, ambient-, and elevated-CO2 conditions. Elevated CO2 (eCO2) induced broad reorganization of carbon and nitrogen metabolism in both genotypes, reducing photorespiratory and stress-associated amino acids and modulating key metabolic ratios, including glycine/serine and malate/aspartate, in a genotype- and time-dependent manner. Proteomics revealed DAPAT photosynthetic compensation under ambient CO2, with RuBisCO over-accumulation and suppressed TOR activity, as indicated by decreased RPS6 phosphorylation, which eCO2 restored in parallel with phenotypic rescue. These adjustments were associated with partial attenuation of the DAPAT metabolic imbalance. Our findings reveal functional connections among lysine biosynthesis, photorespiration, and CO2-responsive metabolic flexibility, demonstrating that lysine metabolism serves as a regulatory node linking amino acid homeostasis to carbon availability and respiratory adjustment. This provides mechanistic insight into how plants maintain energy balance under fluctuating CO2 environments.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"24 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149187915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcription factor ANAC087 coordinates symplastic Cd exclusion and apoplastic Cd sequestration to enhance cadmium resistance in Arabidopsis thaliana","authors":"Su Li, Ye Tao, Lu Zheng, Fang Wei Yu, Qiang Zhang, Chang Zhao Chen, Jing Huang, Shen Yun Wang, Ya Dong Zhang, Ming Qing Liu, Ren Fang Shen, Xiao Fang Zhu","doi":"10.1093/plphys/kiag763","DOIUrl":"https://doi.org/10.1093/plphys/kiag763","url":null,"abstract":"Cadmium (Cd) exclusion and sequestration are vital mechanisms for plant survival under heavy metal stress, yet the upstream regulatory networks governing these coordinated processes remain poorly understood. In this study, we identified the NAC transcription factor ANAC087 as a key positive regulator of Cd resistance in Arabidopsis thaliana. Loss-of-function anac087 mutants exhibited hypersensitivity to Cd stress and significantly higher Cd accumulation in both roots and shoots compared to the wild type (WT) Col-0. Mechanistically, we demonstrate that ANAC087 coordinates two complementary pathways involving symplastic Cd influx control and apoplastic sequestration. First, ANAC087 contributes to ABA homeostasis and directly binds to the promoter of ABSCISIC ACID-INSENSITIVE5 (ABI5) to activate its expression, which subsequently antagonizes the MYB49-bHLH38/101 regulatory module to suppress IRT1, thereby limiting Cd uptake. Exogenous ABA application partially alleviated the Cd-sensitive phenotype of anac087. Second, ANAC087 directly transactivates ANAC017 to promote XTH31-mediated xyloglucan accumulation, substantially enhancing the Cd binding capacity of the root cell wall. Genetic analyses confirmed that ectopic expression of ABI5 or ANAC017 partially rescued the Cd sensitive and high-Cd accumulation phenotypes of anac087, whereas XTH31 overexpression complemented the anac017 anac087 double mutant. Furthermore, Cd stress increases both ANAC087 transcript abundance and protein stability. Collectively, our findings support a regulatory framework in which ANAC087 coordinates processes that limit symplastic Cd accumulation and promote apoplastic Cd sequestration.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"37 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149187916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Franks & Farquhar (2007) and beyond: The influence of guard and subsidiary cell bio-mechanics on stomatal function.","authors":"Tracy Lawson, Michelle Facette, Scott A M McAdam, Tanja A Hofmann","doi":"10.1093/plphys/kiag724","DOIUrl":"https://doi.org/10.1093/plphys/kiag724","url":null,"abstract":"<p><p>Stomata are the gatekeepers to leaf gas exchange and as such are essential for CO2 uptake for photosynthesis, water loss for evaporative cooling and ultimately plant growth and productivity. Research has long focused on understanding the mechanisms that govern stomatal aperture adjustments, in particular how changes in turgor pressure in GCs are achieved and how these cause the reversible cell shape distortion that leads to pore opening and closing. Here we discuss the immense impact the paper by Franks and Farquar (2007) has had on this research field, both in the past and more recently, by stimulating new angles of exploration of stomatal mechanics. As new techniques have emerged, the impact of the mechanical advantage of epidermal/subsidiary cells and how this is overcome by GCs has inspired novel studies into the importance of subsidiary to stomatal function, the effect of different cell shapes (dumbbell vs kidney shaped) on stomatal kinetics, the significance of cell geometries and cell complexes, as well as the underlying biochemical cell wall composition responsible for GC deformation. Whilst many questions remain unanswered, we summarize the take-home messages from the key literature on stomatal biomechanics.</p>","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":8.2,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149147904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CsSSU I differentially modulates plastidial prenyltransferases linked to coloration and aroma in sweet orange (\u0000 Citrus sinensis\u0000 L.)","authors":"Zhehui Hu,Zhiyuan Wang,Guixiang Chen,Zhipeng Zhao,Huan Wen,Dongxuan Wu,Fang Lu,Kaijie Zhu,Xiaoyu Tian,Jiajing Chen,Xiuxin Deng,Guangkai Bian,Juan Xu","doi":"10.1093/plphys/kiag746","DOIUrl":"https://doi.org/10.1093/plphys/kiag746","url":null,"abstract":"Abstract Coloration (carotenoids) and aroma (volatile terpenoids) are major determinants of citrus fruit quality, but their coordinated improvement is challenging because carotenoid and volatile-terpenoid biosynthesis draw on a shared isoprenoid precursor network. Here, we used chimeric fruits of the sweet orange (Citrus sinensis L.) bud mutant “Zongcheng” to investigate this metabolic coordination. Metabolomic analyses revealed coordinated accumulation of carotenoids and volatile terpenoids in the brown peel sectors. We systematically characterized the sweet orange trans-prenyltransferase (TPT) family and identified CsGGPPS4, CsGGPPS6, and CsGGPPS8 as plastid-localized enzymes catalyze geranylgeranyl diphosphate (GGPP) biosynthesis. Comparative transcript profiling, biochemical assays, and in vivo functional analyses revealed distinct functions among these enzymes. Expression profiling and in vivo experiments demonstrated that CsGGPPS6 and CsGGPPS8 promote carotenoid accumulation, whereas CsGGPPS4 exerts only minor effects under the tested conditions. Notably, CsGGPPS6 exhibited substrate-ratio-dependent product specificity, producing predominantly farnesyl diphosphate (FPP) under equimolar substrate conditions but both FPP and GGPP when isopentenyl diphosphate (IPP) was enriched; its manipulation in vivo also altered sesquiterpenoids accumulation. CsSSU I directly interacted with CsGGPPS6 and CsGGPPS8 and differentially modulated their catalytic properties: association with CsGGPPS6 favored FPP formation and restricted further elongation to GGPP, whilst association with CsGGPPS8 enabled geranyl diphosphate (GPP) production and enhances GGPP production. Manipulation of CsSSU I in vivo coordinately affected monoterpenoids, sesquiterpenoids, and carotenoids accumulation. Collectively, these results establish that CsSSU I acts as a protein-binding modulator that remodels product output of plastid-localized TPT enzymes, and indicate that this regulatory network orchestrates terpenoid-derived pigmentation and aroma traits in citrus.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"167 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149150644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Whole-genome duplication reshapes gene–miRNA regulatory networks underlying improved salt stress tolerance in Medicago sativa","authors":"Danilo Fabrizio Santoro, Carmine Del Regno, Aaron W Anderson, Elisa Cappetta, Marisa Conte, Domenico Carputo, Alfredo Ambrosone, Daniele Rosellini","doi":"10.1093/plphys/kiag757","DOIUrl":"https://doi.org/10.1093/plphys/kiag757","url":null,"abstract":"Whole-genome duplication (WGD) is a recurrent feature of plant evolution and crop improvement, yet its direct contribution to abiotic stress tolerance remains difficult to disentangle from hybridization effects. Using full-sibling diploid (2x) and neotetraploid (4x) Medicago sativa genotypes generated through bilateral sexual polyploidization, we investigated how WGD alone reshapes physiological performance and gene–miRNA regulatory networks under salt stress. Neotetraploid plants displayed enhanced tolerance to salinity, maintaining higher chlorophyll content, stomatal conductance, and shoot integrity, alongside reduced visual damage compared with diploid siblings. Transcriptome profiling revealed that ploidy level, rather than salt treatment per se, was the dominant driver of gene expression variation. Indeed, WGD resulted in extensive and largely constitutive transcriptional reprogramming, with more than 2,000 differentially expressed genes (DEGs) distinguishing 4x from 2x plants under both control and saline conditions. By contrast, under salt stress, 705 DEGs specifically differentiated tetraploids from diploids and were enriched in receptor-like kinases, phosphorylation pathways, ubiquitin-mediated proteolysis, flavonoid biosynthesis, and WRKY- and MYB-centered regulatory modules. Co-expression network analysis identified salt-associated modules linking signaling and antioxidant pathways with stress-related physiological traits. Small RNA sequencing further showed that WGD reshapes post-transcriptional regulation, with limited salt-induced miRNA changes but the emergence of ploidy-dependent miRNA hubs, including miR2593e and a novel miRNA, targeting signaling and defense-related genes. We hypothesize that WGD establishes a stress-ready regulatory architecture in which coordinated transcriptional and post-transcriptional network rebalancing acts as a buffering system that improves alfalfa physiological performance under salinity, without strong induction of canonical salt-responsive genes.","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":"22 1","pages":""},"PeriodicalIF":7.4,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149152578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gibberellin-mediated PtrLBD39-PtrHDA6-PtrHCT epigenetic path regulates lignin biosynthesis during tension wood formation in Populus trichocarpa.","authors":"Xiufang Dai, Wen Zhang, Huiting Wang, Jiaman Liu, Jinfeng Zhao, Dekai Meng, Yanjie Chen, Rui Zhai, Jinghui Gao, Jing Yu, Xue Gao, Shuang Li, Xingguo Lan, Vincent L Chiang, Chenguang Zhou, Wei Li","doi":"10.1093/plphys/kiag759","DOIUrl":"https://doi.org/10.1093/plphys/kiag759","url":null,"abstract":"<p><p>Tension wood (TW) is a specialized xylem tissue formed in angiosperm trees to counteract mechanical stresses. Increased phytohormones, particularly gibberellins (GAs), and decreased lignin deposition are two well-established features of TW, yet the molecular mechanisms linking GA signaling to lignin repression remain largely unknown. Here we revealed that TW formation in Populus trichocarpa elevates GA accumulation, which activates the expression of PtrLBD39, the most strongly induced transcription factor and a repressor of lignin biosynthesis in TW development. Inhibition of GA biosynthesis attenuates PtrLBD39 induction and restores lignin deposition in TW development. Consistently, CRISPR PtrLBD39 knockout increased lignin content and endonuclease-deficient Cas9-mediated loci-specific PtrLBD39 activation reduced lignin in TW-forming stems. ChIP-seq analysis and EMSA experiments demonstrated that PtrLBD39 binds directly to the promoters of two monolignol biosynthetic genes, PtrHCT1 and PtrHCT6, via a novel TCACGB motif, thereby repressing their transcription. The PtrLBD39-DNA binding allowed PtrLBD39 to recruit two histone deacetylases, PtrHDA6-A and PtrHDA6-B, from 16 known P. trichocarpa HDACs screened and validated by Y2H, BiFC and in vitro pull-down assays, and the specific recruitments to PtrHCT1 and PtrHCT6 were confirmed during TW development by ChIP-qPCR. PtrLBD39-PtrHDA6-A or PtrLBD39-PtrHDA6-B dimers were functional for deacetylating H3K9ac and H3K14ac on PtrHCT1 and PtrHCT6 leading to transcriptional repression and lignin reduction, as demonstrated in PtrHDA6-A overexpression lines under TW development. Consistently, PtrLBD39 overexpression lines under TW development also affected PtrHCT deacetylation for lignin reduction. Thus, we suggest that mechanical stresses transduce a GA-mediated LBD39-HDA6s-HCTs epigenetic regulatory path for effective causative regulations for TW specialization.</p>","PeriodicalId":20101,"journal":{"name":"Plant Physiology","volume":" ","pages":""},"PeriodicalIF":8.2,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149137234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}