Tree physiology最新文献

{"title":"New insights into the regulatory effects of galloylated catechin on male reproduction in Camellia oleifera.","authors":"Honggang Xu, Jin Feng, Xiaoying Li, Xinmiao Guo, Linke Huang, Zhengzheng Guo, Yihong Chang, Wenfang Gong","doi":"10.1093/treephys/tpag118","DOIUrl":"10.1093/treephys/tpag118","url":null,"abstract":"<p><p>Flavonoids, particularly galloylated catechins, are known to regulate pollen tube growth, but their mode of action in woody plants remains poorly characterized. Here, we investigated the effects of epigallocatechin gallate (EGCG)-a major galloylated catechin-on Camellia oleifera pollen tubes using combined cytological and transcriptomic approaches. In vitro treatment with 100 μg mL-1 EGCG significantly reduced pollen germination and tube elongation. Confocal and fluorescence microscopy revealed that EGCG rapidly disrupted the apical Ca2+ gradient within 10 min, accompanied by disorganized actin filaments and altered distribution of methyl-esterified pectin at the tube apex. Transcriptome profiling and antisense oligonucleotide (AS-ODN)-mediated knockdown identified a Rho GTPase-activating protein (ROPGAP6)-centered regulatory network associated with growth inhibition. Weighted gene co-expression network analysis and subsequent AS-ODN knockdown experiments further revealed transcriptional coordination among Decapping protein 1 (Dcp1), small heat shock factor (sHSF) and ROPGAP6 in response to EGCG treatment. Collectively, our findings offer a multilevel framework for understanding how galloylated catechins regulate pollen tube growth in C. oleifera, providing insights into their roles in male reproduction of trees.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nutrient-mediated tree growth responses are governed by internal resource allocation: intra-organ water-carbon trade-offs and inter-organ carbon concentration gradient.","authors":"Hui Shao, Huimin Wang, Frederick C Meinzer, Xiaoqin Dai, Shengwang Meng, Liang Kou, Decai Gao, Fusheng Chen, Xiaoli Fu","doi":"10.1093/treephys/tpag109","DOIUrl":"10.1093/treephys/tpag109","url":null,"abstract":"<p><p>Nutrient deposition is reshaping forest productivity, yet the physiological mechanisms linking nitrogen (N) and phosphorus (P) enhancement to tree growth remain incompletely resolved. We propose that internal resource allocation strategies-specifically intra-organ trade-offs between water and carbohydrate resources and inter-organ carbohydrate concentration gradient-mediate nutrient-driven tree growth responses. Using a long-term fertilization experiment in subtropical Cunninghamia lanceolata (Lamb.) Hook. plantations, we measured relative water content (RWC) and traditional resource concentrations [soluble sugar (SS) concentration; starch (ST) concentration] during drought season. We rank-transformed RWC, SS and ST within each organ type across all samples. Intra-organ water-carbon trade-offs were quantified as two normalized ratios: ln(RWCrank/SSrank) for RWC:SS and ln(RWCrank/STrank) for RWC:ST, where higher values indicate greater solute dependence for turgor maintenance or greater ST storage volume fraction, respectively. The inter-organ carbon concentration gradient was quantified as differences in SS or ST between leaves and twigs (SSleaf-twig, STleaf-twig); and between absorptive roots and transport roots. We demonstrated three key nutrient-specific responses: (i) N addition promoted transport root ln(RWCrank/SSrank) while enhancing leaf ln(RWCrank/STrank), amplifying STleaf-twig; (ii) P addition reduced leaf and twig ln(RWCrank/SSrank) and (iii) combined N+P addition reduced twig ln(RWCrank/SSrank), while increasing leaf and twig ln(RWCrank/STrank). These reorganization patterns had direct growth consequences: while traditional resource concentrations explained 26.0% of growth variation, incorporating derived attributes increased explanatory power by 43.5% (to 37.3% total variance explained). Notably, the twig ln(RWCrank/STrank) emerged as the single strongest growth predictor, where N+P induced ST dominance correlated with enhanced growth rate. Nitrogen enrichment enhanced SS dominance in transport roots, a pattern that may occur at the expense of stem growth. Our results establish an internal resource allocation framework that mechanistically links nutrient-mediated carbon management patterns to forest productivity under global change, revealing how N+P co-enrichment synergistically optimizes carbon resource storage and utilization beyond single-nutrient effects.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13565153/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148697982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increased pine root exudation of phenolic acids and amino acids under drought.","authors":"Sophie Obersteiner, Yaara Oppenheimer-Shaanan, Tamir Klein","doi":"10.1093/treephys/tpag116","DOIUrl":"10.1093/treephys/tpag116","url":null,"abstract":"<p><p>Belowground carbon (C) allocation by trees, particularly through root exudation, is a key pathway influencing long-term C storage in forest soils. Future climate change scenarios, such as drought and elevated CO2 (eCO2) strongly affect trees' physiology and influence belowground C allocation. However, how the rate and chemical composition of root exudation change, especially under the combined effect of drought and eCO2, remains poorly understood. We conducted an experiment to examine the single and combined effects of drought and eCO2 on the belowground C allocation of Pinus brutia Ten saplings. Root exudates were collected, quantified and metabolically profiled. Our results revealed that under eCO2, C assimilation increased up to 2.2-fold, increasing plant biomass, while the root exudation rate and composition remained unchanged under eCO2 compared with ambient CO2 (aCO2). Additionally, when trees were exposed to drought stress, the root exudation rate increased 4.3-fold under aCO2 and up to 10.4-fold when combined with eCO2; however, overall, eCO2 had no effect on root exudation. Root starch reserves decreased under drought, whereas soluble sugars increased, with the largest increase under combined drought and eCO2. Further, drought altered exudate composition, increasing several metabolites, mainly phenolic acids (e.g., gallic acid and caffeic acid), amino acids and key osmoprotectants such as trehalose, proline and betaine. Overall, these observations show that pines strongly increased their root exudation under drought and that exudate metabolites shifted towards more specialized metabolites linked to stress metabolism.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13601639/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trichoderma-induced increase in rhizosphere soil bacterial diversity contributed to wolfberry growth promotion in saline land.","authors":"Mingye Zhu, Xin Chen, Xiao Liu, Jiangshan Hu, Ziyu Wang, Mengyu Li, Wentong Wang, Kun Yan","doi":"10.1093/treephys/tpag115","DOIUrl":"10.1093/treephys/tpag115","url":null,"abstract":"<p><p>Trichoderma has be proven to enhance plant growth under saline stress. However, there is limited research on Trichoderma-induced alterations of rhizosphere microbial communities in woody plants, and the subsequent effect on their yield is poorly understood. This study was carried out to investigate the growth-promoting mechanism of Trichoderma asperellum on wolfberry (Lycium chinense) in coastal saline land from bacterial community and diversity aspects through a field trial with Trichoderma agent application. Trichoderma agent application significantly increased fruit yield, plant dry weight and nitrogen accumulation, demonstrating that Trichoderma enhanced the salt tolerance of wolfberry. Despite no obvious influence on the structure of bacterial community, Trichoderma agent application significantly increased rhizosphere soil bacterial diversity, with beneficial bacterial genera including Shinella and Flaviaesturariibacter showing increased relative abundances. In addition, Trichoderma agent application enhanced the stability of the soil bacterial co-occurrence network, as evidenced by higher counts of nodes and edges in the network. Furthermore, Trichoderma agent application reduced the abundance of the complete nitrifier Candidatus Nitrospira nitrificans, inhibited soil nitrification and significantly increased soil ammonium nitrogen content, contributing to the improvement of plant nitrogen nutrition. According to random forest analysis, the most significant predictive importance for wolfberry yield was the Shannon index, followed by the relative abundances of beneficial bacteria and soil nitrate nitrogen content, highlighting that the growth-promoting role of Trichoderma could be realized by elevating rhizosphere soil bacterial diversity. Moreover, structural equation modeling indicates that in contrast to the pathway of nitrogen accumulation, the increased yield was primarily achieved by enhancing rhizosphere soil bacterial diversity with Trichoderma agent application. Therefore, Trichoderma promotes wolfberry growth and yield in saline land mainly by elevating rhizosphere bacterial diversity, with improved nitrogen nutrition providing an additional contribution. This study deepens our understanding of the mechanisms by which Trichoderma promotes plant growth, and provides a promising biostimulant for wolfberry cultivation in saline land.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of poplar and spruce GDP-mannose pyrophosphorylases involved in mannan and ascorbic acid biosynthesis.","authors":"Sydne Guevara-Rozo, Shawn D Mansfield","doi":"10.1093/treephys/tpag105","DOIUrl":"10.1093/treephys/tpag105","url":null,"abstract":"<p><p>Mannans are hemicellulosic polysaccharides integral to plant growth and development, yet their functions in trees and the regulation of their synthesis remain poorly understood. Here, we investigated the biosynthesis of guanosine diphosphate (GDP)-mannose, the primary sugar donor required for mannan synthesis. Using phylogenetic analyses, protein domain characterization, and RNA sequencing-based expression profiling, putative GDP-mannose pyrophosphorylase (GMP) candidates were identified in poplar and spruce. Functional validation of candidate genes was performed by complementation of the Arabidopsis vtc1-1 mutant, and by generating CRISPR/Cas9 knockout and ectopic overexpression lines in poplar. Our results showed that poplar PtaGMP1 and spruce PgGMP1 successfully complemented the vtc1-1 mutant, restoring mannan content to wild-type levels. In poplar, CRISPR/Cas9 knockouts of PtaGMP1 reduced mannan by 20% and ascorbic acid by 47%, whereas ectopic overexpression of PgGMP1 increased mannan by 14% without significantly affecting ascorbic acid content. In both cases, these changes did not significantly affect tree growth. Overall, our study provides new insights into the regulation of mannan biosynthesis in trees and the contribution of GMPs to both mannan and ascorbic acid production in poplar.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13544439/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148607921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal dynamics and sun/shade heterogeneity of leaf gas exchange and VOC emissions inside a tall temperate forest canopy.","authors":"Stefanie Dumberger, Yasmina Frey, Clara Stock, Sophie Wehlings-Schmitz, Delon Wagner, Kathrin Kühnhammer, Lea Dedden, Markus Weiler, Markus Sulzer, Andreas Christen, Jürgen Kreuzwieser, Ulrike Wallrabe, Christiane Werner, Simon Haberstroh","doi":"10.1093/treephys/tpag111","DOIUrl":"10.1093/treephys/tpag111","url":null,"abstract":"<p><p>Leaf gas exchange is the key driver of forest carbon uptake and directly determines forest carbon sink activity. Additionally, plants release a variety of biogenic volatile organic compounds (VOCs) acting as stress signals of trees. However, continuous hourly resolved measurements of leaf gas exchange and VOC emissions in tall tree canopies are challenging and remain scarce. To this end, we developed a complex in-situ leaf gas exchange measurement system with 24 cuvettes deployed on mature Fagus sylvatica L. (n = 3) and Pseudotsuga menziesii (MIRBEL) FRANCO (n = 3) individuals in a mixed temperate forest. We additionally measured sap flux density (Js), radial growth and tree water deficit (TWD) to gain a holistic picture of seasonal leaf and stem water and carbon flux dynamics during the summer of 2024. During midsummer, we found a gradual reduction of stomatal conductance (gs) and VOC emissions of sun but not shade branchlets of P. menziesii in response to moderate atmospheric and edaphic drying. Decreased gs led to a downregulation of transpiration, Js and carbon isotope discrimination accompanied by an increase in TWD and intrinsic water-use efficiency. Leaf gas exchange of shade branchlets remained unaffected due to microclimatic buffering effects. Contrarily, sun leaves of F. sylvatica profited from sunny midsummer conditions and increased leaf gas exchange, whereas shade leaves benefitted from more diffuse light during early summer exhibiting similar carbon assimilation, transpiration and VOC emissions as sun leaves. For both species, we found a clear time lag of 4-5 h between maximum leaf and stem water fluxes and a delay of up to 20 h for the recovery of TWD, highlighting the role of stem water reserves. Pronounced seasonal and diurnal differences of leaf gas exchange, stem water fluxes and VOC emissions showed that continuous data are essential to better understand the variability of ecosystem flux dynamics.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increased pod shattering of Caragana species adapted to arid environments.","authors":"Rui-Yun He, Di Yang, Deng Yang, Shun-Ping Han, Shi-Qing Yuan, Yu-Hang Zhang, Jiang-Hang Wu, Yan-Ling Nong, Xiang-Wen Fang","doi":"10.1093/treephys/tpag113","DOIUrl":"10.1093/treephys/tpag113","url":null,"abstract":"<p><p>Pod shattering, in which mature pods split along their dorsal and ventral sutures, has been widely reported in legume crops due to yield losses. However, the pod-shattering behavior of native legumes that have adapted to decreasing precipitation remains poorly understood. In this study, pod-shattering rates, histology, pod wall components, hydrolase activity and transcriptome of the pod ventral sutures were measured in six Caragana species adapted to a wide range of mean annual precipitation (MAP) conditions and growing in a common garden. Species from low-MAP environments presented higher pod-shattering rates, which were associated with a more pronounced abscission zone (AZ), more pod wall torsion laps, lower contents of cellulose and pectin, and increased activities and gene expression levels of polygalacturonase (PG) and cellulase (CE). In contrast, species from high-MAP environments presented lower pod-shattering rates, which were associated with the absence of an AZ, lower pod wall torsion laps, higher cellulose and pectin contents, and reduced activities and gene expression levels of PG and CE. This study hypothesizes that pod-shattering synchronizes seed release to match rainfall patterns, offering a new perspective for understanding the natural distribution of legumes adapted to arid environments.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low ambient temperature induces flowering of Osmanthus fragrans via SOC1A/SOC1B protein complex-mediated activation of FT.","authors":"Yangang Lan, Ziyi Li, Xue Huang, Xiaoyan Zhou, Danni Yaosha, Yiguang Wang, Jinping Deng, Xuening Liu, Hongbo Zhao","doi":"10.1093/treephys/tpag120","DOIUrl":"10.1093/treephys/tpag120","url":null,"abstract":"<p><p>Temperature critically influences flowering time, yet the molecular mechanisms governing this process in perennial woody species remain largely elusive. Based on flowering characteristics, Osmanthus fragrans Lour. can be divided into two major groups: once-flowering types and continuous-flowering types (the Asiaticus group). Among these, the floral transition of continuous-flowering types is precisely regulated by ambient temperature. Here, using O. fragrans 'Sijigui' (a cultivar of the Asiaticus group) as experimental material, we combined phenotypic observation with paraffin sectioning analysis under different ambient temperature treatments. The results showed that relatively low ambient temperature induced floral transition, whereas relatively high ambient temperature suppressed this process. By conducting transcriptome sequencing and weighted gene co-expression network analysis, we found that SOC1A and SOC1B, members of the MADS-box family, play key roles in ambient temperature-induced flowering of O. fragrans. SOC1A/1B are localized in the nucleus and cytoplasm, and their expression and promoter activity are significantly induced by low ambient temperature. Overexpression of SOC1A/1B significantly activates the expression of flowering-related genes and promotes flowering in transgenic plants. Yeast one-hybrid, electrophoretic mobility shift assay and dual-luciferase reporter assays verified that both SOC1A and SOC1B directly target and activate the downstream flowering gene FT. Intriguingly, GST pull-down, split-luciferase complementation (Split-LUC) and bimolecular fluorescence complementation assays confirmed that SOC1A physically interacts with SOC1B both in vitro and in vivo to form a protein complex. Furthermore, their protein interaction enhances the transcriptional activation of FT, thereby synergistically modulating low ambient temperature-induced flowering in O. fragrans. In conclusion, our study initially identified the key genes involved in low ambient temperature-induced flowering of O. fragrans, laying a foundation for revealing the molecular mechanism of ambient temperature regulating flowering in perennial woody plants.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-omics analysis reveals the mechanisms of biochar-mediated cadmium transport in Salix: insights into rhizosphere phosphorus-iron coupling and transporter expression.","authors":"Dongliu Di, Shaokun Wang, Wenmin Qiu, Xu Gai, Jiang Xiao, Shufeng Wang, Renying Zhuo, Guangcai Chen","doi":"10.1093/treephys/tpag104","DOIUrl":"10.1093/treephys/tpag104","url":null,"abstract":"<p><p>Biochar addition promotes cadmium (Cd) phytoremediation of woody plants, especially phosphorus (P)-modified biochar. However, the underlying mechanism of the uptake and transport of Cd transport mediated by biochar remains unclear. Here, we integrated physiological, metagenomics, transcriptomics and in situ laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging analysis to investigate how bamboo biochar (BBC) and phytic acid-modified biochar (PABC) impact Cd accumulation and transport in Salix J1010 through root-soil interface. Our results showed that PABC significantly increased Cd translocation from roots to aboveground by 77.9% and total Cd accumulation in plants by 203%, respectively. Iron plaque emerged as a key factor, with PABC-mediated inhibition of iron plaque (-44.6%) accelerating Cd uptake. This iron plaque decrease is closely accompanied by the decreased soil redox potential (Eh), enriched resin-P and inorganic P fractions, and potential coupling of P mineralization and Fe(III)-reducing processes in the rhizosphere soil. Transcriptomics analysis further revealed that PABC influenced root metal transporters expression, downregulating vacuolar sequestration-related ABC, CAX, metal tolerance protein gene families, while upregulating most ZIP, HMA and YSL genes families involved in xylem loading. LA-ICP-MS imaging corroborated the enhanced Cd transport in xylem tissue. PABC enhanced leaf cell-wall Cd binding and antioxidant defenses, thereby promoting Cd detoxification and accumulation. Collectively, the enhanced phytoremediation capacity of willow was driven by coordinating trade-offs across multiple levels, including the rhizosphere, subcellular scales and whole plant. These results provide a mechanistic basis for biochar-assisted phytoremediation strategies in Cd-contaminated soils.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148607953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanisms underlying the heartwood color difference between Catalpa bungei and Catalpa lutea and their correlation with wood properties.","authors":"Xiaochi Yu, Fei Yi, Jiangtao Zhang, Bingshan Zeng, Junchen Wang, Mei Yuan, Peng Zhang, Wenjun Ma, Junhui Wang","doi":"10.1093/treephys/tpag112","DOIUrl":"10.1093/treephys/tpag112","url":null,"abstract":"<p><p>Catalpa bungei C. A. Mey is a precious timber species endemic to China, and its congeneric species Catalpa lutea J.H.Wang, W.J.Ma & Z.Y.Li possesses higher economic value due to its distinctive golden-yellow heartwood. To elucidate the metabolic and molecular mechanisms underlying the heartwood color difference between C. lutea and C. bungei, as well as the potential associations between heartwood color and wood properties, we conducted metabolomic and transcriptomic analyses on the sapwood, transition zone and heartwood of 21-year-old C. bungei and C. lutea trees, and systematically evaluated their wood anatomical structure, physical and mechanical properties, and decay resistance. The results showed that compared with C. bungei, 17 chromogenic metabolites (10 quinones, 7 flavonoids) were significantly accumulated in the heartwood of C. lutea, among which α-lapachone derivatives (especially 9-hydroxy-α-lapachone and 4,9-dihydroxy-α-lapachone) accounted for 69.99% of the total chromogenic substances, representing the major color-contributing compounds in C. lutea heartwood. Through Gene Ontology enrichment analysis and expression profiling, five CbuCYP450 genes with hydroxylation functions, namely CbuCYP86A1 (evm.TU.group330.7), CbuCYP82A3A (evm.TU.group3.584), CbuCYP82A3B (evm.TU.group3.585), CbuCYPH3 (evm.TU.group11.1088) and CbuCYP71D95 (evm.TU.group11.1150) were identified as highly expressed in the transition zone of C. lutea, potentially involved in the hydroxylation steps of α-lapachone-derivative biosynthesis. Wood-property measurements revealed that, compared with C. bungei, C. lutea possessed significantly higher double wall thickness and wall-to-lumen ratio in fiber cells, as well as significantly superior wood density, hardness, compressive and tensile strengths, and natural decay resistance. The biosynthesis of the identified chromogenic metabolites, particularly α-lapachone and its derivatives, may be associated with the high expression of CbuCYP71D95 and other CbuCYP450 genes. Furthermore, the anatomical structure characterized by thick-walled and narrow-lumened cells, together with the abundant secondary metabolites, jointly endow C. lutea with excellent mechanical properties and decay resistance. This study provides a theoretical foundation for the color-targeted breeding of C. bungei and C. lutea and for the high-value genetic improvement of precious timber species.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}