Tree physiology最新文献

{"title":"Provenance effect on the fine-root metabolome and structure of mature Scots pine revealed in a long-term common garden experiment.","authors":"Agnieszka Szuba, Pulak Maitra, Katarzyna Hrynkiewicz, Izabela Ratajczak, Daniel J Chmura, Joanna Mucha","doi":"10.1093/treephys/tpag126","DOIUrl":"10.1093/treephys/tpag126","url":null,"abstract":"<p><p>Rapid changes in temperature and precipitation present a major challenge for long-lived forest trees, as their long generation times limit the required rate of adaptive responses within populations. Common garden experiments provide valuable insights into local adaptation, but belowground responses remain understudied. We investigated fine root metabolomes, biochemistry and structure in 54-year-old Pinus sylvestris L. originating from two contrasting environments: a local lowland site and a colder high-elevation mountain region, both grown in a common garden. Untargeted gas chromatography-tandem mass spectrometry profiling identified 160 metabolites and revealed pronounced effects of both season and tree origin. In spring, roots from high-elevation trees exhibited a distinct metabolomic profile characterized by lower concentrations of nitrogen-containing compounds and elevated levels of lipid derivatives, including fatty acids and sterols. In contrast, autumn roots from both origins showed broadly similar metabolite abundances. According to biochemical analyses, seasonal shifts were also evident in carbohydrate dynamics, with higher concentrations of non-structural carbohydrates in spring and increased structural carbohydrates deposition in autumn. Nitrogen compounds, particularly amino acids, increased in autumn roots of both tree origins, most likely reflecting nutrient storage. Differences related to tree origin extended to root morphology, as roots from high-elevation trees had higher cell wall carbohydrate content and altered root branching patterns compared with those from lowland trees. Our findings suggest that tree origin leaves a clear imprint on the fine root metabolome and structure of mature Scots pine, with most pronounced differences occurring in early spring. These results highlight how inherited adaptation to origin climates interacts with seasonal soil processes. High-resolution metabolomics thus offers a powerful tool for detecting subtle belowground provenance-related belowground effects that may be overlooked by traditional trait-based approaches, providing new perspectives on possible tree adaptation under climate change.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13652640/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148907191","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":"Whole-plant hydraulic integration is linked to multiscale anatomical coordination in evergreen broad-leaved trees.","authors":"Yang-Lu Ou, Lian-Xia Huang, Qing Yang, Ya-Ming Ling, Han-Mei Huang, Shi-Dan Zhu, Xinyi Guan","doi":"10.1093/treephys/tpag129","DOIUrl":"10.1093/treephys/tpag129","url":null,"abstract":"<p><p>Whole-plant hydraulic strategies depend on coordinated hydraulic structure and function across organs. However, how hydraulic safety, efficiency and water storage are integrated across the whole plant and linked to multiscale xylem anatomy remains poorly understood. We quantified hydraulic traits in leaves, stems and coarse roots of 12 dominant tree species from a northern tropical evergreen broad-leaved forest. We also characterized their xylem anatomy at pit, vessel and tissue scales. Coarse roots were more vulnerable to embolism than stems and leaves but had higher theoretical hydraulic conductivity (Kth) and hydraulic capacitance (C). Leaves had the lowest Kth and C and the most negative turgor loss point. Stems had water potentials at 50% embolism formation (P50) comparable to those of leaves, whereas their C values were intermediate between leaves and coarse roots. Principal component analysis separated species along aboveground and belowground hydraulic axes, with the aboveground axis associated mainly with embolism resistance and water potential buffering, and the belowground axis associated with water acquisition and storage. Across organs, covariation between P50 and C suggested a trade-off between embolism resistance and water-storage capacity, consistent with contrasting drought-tolerance and drought-avoidance hydraulic strategies. Intervessel pit membrane surface area was associated with Kth and C, vessel grouping traits with P50 and tissue allocation indirectly with P50 through C. Together, these findings suggest that whole-plant hydraulic strategies in evergreen broad-leaved trees reflect organ specialization and multiscale anatomical coordination rather than variation along a single dominant hydraulic axis.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148913516","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":"Elevated CO2 buffers negative impacts of heat stress on short-term growth adjustments of 180-year-old Quercus robur.","authors":"Anna Gardner, Angus R MacKenzie, Muhammad S Amjad, Stefan Krause, Joshua Larsen, Susan Quick, Klaske van Wijngaarden, Alice Gauthey","doi":"10.1093/treephys/tpag114","DOIUrl":"10.1093/treephys/tpag114","url":null,"abstract":"<p><p>Rising atmospheric carbon dioxide (CO2) concentration are a primary driver of global warming and are expected to be associated with more frequent droughts, greater temperatures and increased vapour pressure deficit (VPD). These factors are all key drivers of tree mortality. Whilst elevated CO2 (eCO2) enhances photosynthesis (Anet) and intrinsic water-use efficiency (iWUE), its capacity to mitigate heat stress in mature trees under field conditions remains poorly understood. We investigated the effects of eCO2 on the physiological and growth responses of mature Quercus roburL. (~180 years old) at a forest Free Air Carbon Enrichment (FACE) experiment. We combined measurements of tree growth, canopy conductance and leaf gas exchange, together with leaf morphological traits, collected during a naturally occurring heat events (>32 °C), to assess whether eCO2 buffered the impacts of extreme heat events (>32 °C). The leaf-level measurements also enabled us to determine whether the physiological enhancements previously observed during the early years of Birmingham Institute of Forest Research FACE were maintained following prolonged exposure to CO2. After 8 years of CO2 enrichment (+150 p.p.m. above ambient), eCO2-grown trees showed increased iWUE (+33%), driven by increased Anet (+26.1%) and modest reductions in stomatal conductance (-11.1%), with no significant changes in stomatal anatomy. Elevated CO2 increased the sensitivity of canopy-level conductance to VPD during heat events, indicating stronger stomatal regulation under high atmospheric demand in eCO2 compared with ambient CO2-grown trees. Heat stress reduced tree growth in both conditions, but the reduction was less pronounced under eCO2, suggesting partial mitigation of heat stress effects. These findings indicate that eCO2 can confer partial physiological buffering against heat stress in mature Q. robur, enhancing resilience without compromising structure. Shifts in water use highlight the importance of integrating CO2-climate interactions when predicting forest responses to future climate extremes.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13669954/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798266","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":"Abscisic acid and nitric oxide confer poplar rust resistance through host defense activation and cross-kingdom regulation of effector genes.","authors":"Xinrong Zhang, Yi Zeng, Yi Yang, Linchao Xia, Yao Chen, Sheng Zhang","doi":"10.1093/treephys/tpag132","DOIUrl":"10.1093/treephys/tpag132","url":null,"abstract":"<p><p>Leaf rust disease caused by Melampsora larici-populina Klebahn severely impacts the photosynthesis and growth of Populus cathayana Rehder, causing substantial productivity losses in forest trees. Abscisic acid (ABA) and nitric oxide (NO) are known to play key roles in plant defense. However, their synergistic interplay in woody plant rust resistance remains unresolved. Here, we investigated the roles of ABA and NO in P. cathayana defense against the biotrophic rust fungus M. larici-populina using physiological, transcriptomic and transgenic approaches. Exogenous ABA and the NO donor sodium nitroprusside synergistically enhanced rust resistance by inducing stomatal closure, modulating reactive oxygen species homeostasis, promoting lignin deposition and increasing chitinase activity. Transcriptomic profiling revealed that ABA modulated phenylpropanoid and amino sugar/nucleotide sugar metabolism pathways, with differentially expressed genes in these pathways tightly correlating with lignin biosynthesis and chitinase activity. Among these, the chitinase gene PcCHIB1 was identified and functionally validated as a pivotal positive regulator of rust resistance, as its overexpression significantly reduced fungal biomass, whereas knockout compromised resistance. Notably, ABA exerted cross-kingdom regulatory effects on M. larici-populina, downregulating genes involved in the spliceosome pathway and two small secreted protein effector genes (MLP105684 and MLP124543) that are critical for fungal virulence. Collectively, these findings establish a bipartite defense paradigm in which ABA and NO synergistically reinforce host basal defense while ABA suppresses fungal virulence, providing a mechanistic foundation for engineering rust resistance in poplar.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148945633","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":"Linking chilling with forcing: ontogenetic competence in process-based tree phenology models.","authors":"Rui Zhang, Jianhong Lin, Zhijun Li, Jinbin Zheng, Guillaume Charrier, Heikki Hänninen, Jiasheng Wu","doi":"10.1093/treephys/tpag130","DOIUrl":"10.1093/treephys/tpag130","url":null,"abstract":"<p><p>Process-based models are widely used for predicting the timing of spring phenological events, such as vegetative bud burst or flowering, in extratropical trees. These models address both the effects of low (chilling) temperatures on rest break (endodormancy release) and those of high (forcing) temperatures on the microscopic ontogenetic development inside the buds which leads to the visible bud burst. In this Methods paper we discuss the use of the theoretical quantity ontogenetic competence, Co, in linking chilling with forcing in such process-based models. In the first part of the study, with the aid of a methodological comparison of two modelling approaches we show that Co provides a biologically more realistic option than the more frequently used empirical alternating model for linking chilling with forcing. This is because Co makes it possible to use an explicit state variable for the ontogenetic development leading to bud burst. The alternating model does not allow that, but its strength is simplicity and its straightforward relation to empirical data. In the second part of the study not related to the alternating model we revised the calculation of the empirical values of Co in our experimental method for the process-based spring phenology modelling. This revision was done to take variation of bud burst percentage in the experimental results into account in a biologically more realistic way. In general, the revision did not cause any consistent improvement in the accuracy of the model in predicting spring phenology, nor any major change in the predicted values of Co. The predicted timing of spring phenology under current climatic conditions and the acceleration rate of it under climatic warming, too, were only marginally affected by the revision. However, use of the revised experimental method is recommended because it further improves the biological realism of the models by allowing a more realistic addressing of the bud burst percentage observed in the experiments carried out for the modelling.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148913558","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":"The dark septate endophyte S16 enhances drought tolerance in sweet cherry by coordinating metabolic reprogramming and the transcription factor PaHB12.","authors":"Wenfei Li, Dehui Qu, Qingmei Pang, Jiaqi Zhou, Haoyuan Wang, Songlin Li, Minghui Lv, Lina Yang, Wei Tian, Fanlin Wu, Hongyan Su","doi":"10.1093/treephys/tpag131","DOIUrl":"10.1093/treephys/tpag131","url":null,"abstract":"<p><p>Drought severely limits the growth and productivity of sweet cherry (Prunus avium L.), a fruit crop highly sensitive to water deficit. Beneficial root-associated fungi, particularly dark septate endophytes (DSEs), have emerged as potential modulators of stress tolerance, yet their underlying mechanisms in perennial fruit trees remain poorly understood. In this study, we investigated the effects of the DSE fungus Helotiales sp. S16 on drought responses of sweet cherry rootstock Gisela 5 seedlings. Fungal symbiosis was established by homogenizing fungal suspension with sterile growth substrate, and drought stress treatment was implemented 4 weeks after inoculation. Under drought conditions, inoculated seedlings accumulated markedly higher soluble sugar contents, which coincided with upregulated expression of carbohydrate-metabolism-related genes. Lipidomic and transcriptomic data demonstrated that fungal inoculation activated fatty-acid biosynthetic pathways and reshaped overall fatty-acid profiles. Hormone profiling showed elevated abscisic acid, jasmonic acid and salicylic acid levels, accompanied by suppression of auxin (IAA), and cytokinins (6-BA), indicating a reprogramming of hormonal crosstalk. Co-expression network analysis further identified the transcription factor PaHB12 as a regulatory hub in the S16-mediated drought response. These findings demonstrate that DSE fungus S16 enhances drought tolerance through integrated reprogramming of carbon allocation, membrane lipid composition and hormone crosstalk, providing a mechanistic basis for its potential application in sustainable orchard management.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148945588","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":"Two alcohol dehydrogenases enhance Bursaphelenchus xylophilus resistance in Pinus massonniana via 3-hexenol biosynthesis accumulation.","authors":"Bin Liu, Shan Hu, Haiyu Zhou, Qingyang Chen, Kai Gao, Zhichun Zhou, Qinghua Liu","doi":"10.1093/treephys/tpag110","DOIUrl":"10.1093/treephys/tpag110","url":null,"abstract":"<p><p>Green leaf volatiles, oxygenated compounds released by plants under biotic and abiotic stresses, play essential roles as signaling molecules in plant immune responses. However, the defense mechanisms mediated by these volatiles remain poorly characterized in conifers, particularly regarding Pinus massoniana against the invasive pine wood nematode (PWN, Bursaphelenchus xylophilus). Here, we systematically integrated transcriptomic and metabolic profiles to compare the defense responses of resistant and susceptible P. massoniana following PWN inoculation. Our results revealed that alpha-linolenic acid metabolism showed a positive response to PWN infection in resistant P. massoniana. Notably, (Z)-3-hexenol and its ester derivatives, along with the key alcohol dehydrogenases (ADH ) genes in the linolenic acid pathway, were significantly activated in resistant P. massoniana at 7 days post-inoculation. Tissue-specific expression profiling of PmADH12 and PmADH13 demonstrated that they were crucial positive regulators in response to PWN challenge in resistant P. massoniana. Functional characterization confirmed that overexpression of PmADHs efficiently increases the production of (Z)-3-hexenol and its ester derivative in P. massoniana. In addition, these PmADHs encode enzymes capable of catalyzing (Z)-3-hexenal to produce (Z)-3-hexenol. Furthermore, in vitro bioassays revealed that (Z)-3-hexenol, the primary enzymatic product of PmADHs, effectively inhibited the PWN survival. Our findings provide mechanistic evidence that ADHs-mediated (Z)-3-hexenol biosynthesis constitutes a chemical defense strategy against PWN infestation in resistant P. massoniana.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148798147","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":"Conservative versus flexible physiological and metabolic acclimation of Norway spruce and European beech under elevated CO2, nitrogen supply and water availability.","authors":"Kojo Kwakye Ofori-Amanfo, Karel Klem, Petr Holub, Barbora Veselá, Michal Oravec, Kristýna Večeřová, Thomas Agyei, Roman Sándor, Stanislav Juráň, John Grace, Michal V Marek, Otmar Urban","doi":"10.1093/treephys/tpag125","DOIUrl":"10.1093/treephys/tpag125","url":null,"abstract":"<p><p>Elevated atmospheric carbon dioxide (CO2) (EC) can enhance photosynthesis, biomass accumulation and water-use efficiency (WUE), but responses depend on water and nutrient availability and differ among tree species. Multifactorial studies addressing these interactions remain scarce. We examined interactive effects of EC (~700 μmol mol-1), nitrogen supply (nitrogen addition, N+; no nitrogen addition, N-) and water availability (well-watered, WW; drought-stressed, DS) on physiological and metabolic responses of more anisohydric European beech (Fagus sylvatica L.), which maintains stomatal opening longer during drought, and more isohydric Norway spruce (Picea abies (L.) Karst.), which closes stomata earlier to stabilize leaf water status. Across both species, EC produced the largest shifts in gas exchange and metabolite profiles, while water and nitrogen availability strongly modified these responses. Elevated CO2 generally increased net CO2 assimilation and WUE and reduced stomatal conductance, although responses differed between species and treatments; WUE was highest under EC × DS × N+. Species divergence was most evident in biochemical acclimation. In beech, EC markedly reduced photosynthetic capacity, reflected in lower Rubisco carboxylation capacity (VCmax) and electron transport rate (Jmax) across water and nitrogen treatments. This response was accompanied by lower succinate and foliar nitrogen and by resource-dependent shifts in amino acids, phenolic and stress-related metabolites, consistent with greater metabolic reorganization and photosynthetic downregulation. In contrast, spruce maintained comparatively stable VCmax and Jmax under EC, including under DS and N- conditions, together with comparatively stable primary metabolism and sustained phenolic-based defence. Overall, beech showed greater physiological and metabolic flexibility but stronger downregulation of photosynthetic capacity under EC, whereas spruce maintained a more conservative physiological strategy and greater biochemical stability. These contrasting responses highlight species-specific acclimation to CO2 enrichment and its modulation by water and nitrogen availability.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13652638/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148913578","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":"Sympatric European white oaks species display contrasting epigenetic response to soil water availability.","authors":"Bernadette Rubio, Grégoire Le Provost, Benjamin Brachi, Théo Gerardin, Oliver Brendel, Jorg Tost, Christian Daviaud, Philippe Gallusci","doi":"10.1093/treephys/tpag134","DOIUrl":"10.1093/treephys/tpag134","url":null,"abstract":"<p><p>In the context of climate change plants have to cope with adverse conditions, among which water scarcity is a major threat to their survival. They have developed diverse regulatory processes to face drought that differ depending on their ecological niche. The two sympatric oaks species (Quercus robur L. and Quercus petraea (Matt.) Liebl) have different levels of drought tolerance. We investigated their strategies for facing drought stress by analysing the transcriptome, small-RNAome and methylome dynamics of young plants grown under control and drought stress conditions. Data indicate that cell wall remodeling is most likely involved in the better tolerance Q. petraea than of Q. robur. Furthermore, major methylation differences were identified between both oak species that were in part associated to their difference in drought stress responses. Integration of the three datasets revealed genomic co-locations of potential importance for forest tree adaptation to drought stress. Our data are consistent with species-specific molecular responses of oak to drought stress related to their ecological niches.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148956808","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":"Parent-of-origin effects on allelic expression bias in interspecific poplar hybrids.","authors":"Xiang Liu, Si-Dan Hong, Wen-Xiang Cai, Ze-Yu Wu, Ying Guo, Scott A Harding, Chung-Jui Tsai, Liang-Jiao Xue","doi":"10.1093/treephys/tpag128","DOIUrl":"10.1093/treephys/tpag128","url":null,"abstract":"<p><p>In hybrid plants, phenotypic outcomes are governed by interactions between the two parental genomes. However, the mechanisms underlying the interplay of divergent regulatory networks from these genomes remain poorly understood. In this study, we compared gene-level and allele-specific expression patterns, as well as differentially enriched pathways between F₁ and complex backcross lines derived from a natural interspecific hybrid population of Populus fremontii S. Watson (Pf) and Populus angustifolia E. James (Pa). Metabolic differences between Pf and Pa, which exhibit low and high levels respectively of phenylpropanoid-derived condensed tannins, were leveraged. Using individualized transcriptome references, differential expression and clustering analyses revealed CBC-biased and F₁-biased expression for genes involved in phenylpropanoid metabolism and photosynthesis, respectively. Biased expression of these genes at the allele level was also observed in F1. At the whole-transcriptome level, Pa-biased genes predominated in F₁ hybrids, and Pa alleles displayed more conserved expression patterns than Pf alleles across examined samples. Further analyses indicated that allelic expression bias was significantly associated with parental origin, which could be driven by sequence variations in cis-regulatory elements and differences in Cytosine-phosphate-Guanine (CpG) island length. Our findings demonstrate strong parent-of-origin effects on divergent regulatory networks governing gene expression in poplar hybrids and provide clues for strategic parental selection tailored to specific metabolic pathways of interest.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148907110","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}