Tree physiology最新文献

{"title":"Arbuscular mycorrhizal fungi alleviate manganese toxicity in trifoliate orange through dual mechanisms of external barrier and internal detoxification.","authors":"Cheng-Zhuo Li, Lu-Lu Meng, Fu-Qi Xu, Ying-Ning Zou, Qiang-Sheng Wu, Ren-Hua Huang, Abeer Hashem, Elsayed Fathi Abd Allah","doi":"10.1093/treephys/tpag085","DOIUrl":"10.1093/treephys/tpag085","url":null,"abstract":"<p><p>Manganese (Mn) toxicity, exacerbated by soil acidification and anthropogenic pollution, poses a significant threat to plant growth and ecosystem health, particularly in economically important citrus plants. This study tried to uncover the mechanisms by which the arbuscular mycorrhizal fungus Funneliformis mosseae (T.H. Nicolson & Gerd.) C. Walker & A. Schüßler enhances Mn tolerance in trifoliate orange (Poncirus trifoliata) seedlings under excess Mn stress (20 mmol L-1 MnSO4). Although Mn stress inhibited root colonization by F. mosseae, inoculation with F. mosseae significantly alleviated the Mn-induced suppression of plant growth, root system architecture, photosynthetic efficiency and photochemical activity of photosystem II. Crucially, arbuscular mycorrhizal fungi colonization reduced Mn accumulation in leaves, stems and roots, alongside decreased the Mn bioconcentration and translocation factors. Mechanistically, F. mosseae enhanced Mn tolerance in trifoliate orange through two complementary strategies: external exclusion and internal detoxification. Externally, F. mosseae increased levels of difficultly extractable glomalin-related soil protein to sequestrate Mn in the rhizosphere, and significantly upregulated fungal suppressor of mitochondrial fission genes (FmSMF1 and FmSMF2) to enhance hyphal sequestration, thereby blocking Mn entry into roots. Internally, F. mosseae modulated the subcellular distribution and chemical forms of Mn in trifoliate orange: they promoted Mn compartmentalization into the cell wall and soluble (vacuolar) fractions, while reducing its accumulation and proportion in sensitive organelles such as chloroplasts and mitochondria. Furthermore, Mn was transformed from highly active, toxic forms (ethanol- and water-extractable) into more stable, inert forms (e.g. pectate- and phosphate-bound). Consistent with the reduced Mn uptake and toxicity, the expression of host metal tolerance protein (PtMTP8 and PtMTP11) and superoxide dismutase (PtMnSOD) genes was significantly downregulated in mycorrhizal roots under Mn toxicity. In conclusion, F. mosseae enhances Mn tolerance in trifoliate orange through a synergistic dual mechanism, establishing an external barrier via fungal-mediated immobilization and building an internal defense line by reprogramming host Mn compartmentalization and detoxification pathways, thereby minimizing Mn phytotoxicity.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148278837","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":"From microscopic movements to forest-scale insights: the Nordic Dendrometer Meeting and the emergence of the Global Dendrometer Network.","authors":"Danielle Creek, Christina A Hackmann, Tommaso Jucker, Mukund P Rao, Yann Salmon, Mianzhi Wang, Yuwen Zhang, Daniela Nemetschek","doi":"10.1093/treephys/tpag082","DOIUrl":"10.1093/treephys/tpag082","url":null,"abstract":"","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13358874/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148377136","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":"Absorptive root traits shape phosphorus acquisition strategies defined by trade-offs between phosphorus uptake and utilization under soil nutrient limitation and drought stress.","authors":"Miao Yu, Liuduan Wei, Tianxin Dong, Zhihui Yang, Xinna Zhang, Bingqian Ma, Ülo Niinemets, Chengyang Xu","doi":"10.1093/treephys/tpag083","DOIUrl":"10.1093/treephys/tpag083","url":null,"abstract":"<p><p>Nutrient limitation and drought stress often co-occur and jointly influence tree phosphorus (P) acquisition and variation in absorptive root traits. However, it remains unclear whether interspecific variation in P acquisition strategies under combined stress reflects a trade-off between P uptake rate (PUR) and P utilization efficiency (PUE), and how this variation is associated with absorptive root morphology and P uptake kinetic characteristics. Seedlings of four broad-leaved deciduous tree species, Quercus variabilis Blume, Prunus davidiana (Carrière) Franch., Acer truncatum Bunge, and Koelreuteria paniculata Laxm., were grown for 8 weeks in a 3 × 3 factorial experiment with three nutrient limitation levels and three drought severity levels. We then measured total biomass, PUR, PUE, P uptake kinetic characteristics (Vmax, Km and α) and absorptive root morphological traits (root order ≤ 3), including specific root length (SRL), specific root surface area (SRA), root diameter (RD) and root tissue density (RTD). Species exhibited distinct P acquisition strategies under nutrient limitation and drought stress. Acer truncatum and K. paniculata showed a more acquisitive strategy, with higher PUR, greater SRL and SRA, and lower RD and RTD. In contrast, Q. variabilis and P. davidiana showed a more conservative strategy, with higher PUE and denser absorptive roots. Among P uptake kinetic characteristics, α showed the clearest association with these interspecific strategies. We identified a trade-off between PUR and PUE under combined nutrient limitation and drought stress, with tree species differing in the extent to which they relied on uptake versus utilization. These contrasting acquisitive and conservative strategies were associated with variation in absorptive root morphology, with α providing the clearest kinetic link, consistent with a root economic framework for P acquisition under stress.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148273133","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":"Effect of long-term heat stress on structure and function of epidermal tissues in needles of treeline conifer seedlings.","authors":"Giuseppe Tiloca, Othmar Buchner, Notburga Gierlinger, Gilbert Neuner","doi":"10.1093/treephys/tpag080","DOIUrl":"10.1093/treephys/tpag080","url":null,"abstract":"<p><p>Tree seedlings at the treeline face various environmental extremes; in particular, their needles can heat up close to thermal limits. Unlike mature-tree needles, treeline conifer seedlings resist heat-induced water loss better, even though their cuticle lacks an outer layer. To determine whether these differences are due to ontogenetic factors or acclimative responses to higher heat loads, conifer seedlings were exposed to a controlled in situ long-term heat treatment. By comparing the rate of water loss through the cuticle (minimum diffusive conductance, gmin), cuticle thickness and chemical micro-composition of control versus heated seedlings of deciduous Larix decidua Mill. and evergreen Picea abies (L.), we intended to assess the acclimative plasticity of these traits. We also aimed to identify specific heat-induced changes in cuticle structure and function. The controlled, in situ, long-term heat treatment lasted for 6 weeks with air temperature set 10-15 K above the ambient air (controls) with a set maximum leaf temperature of 42 °C. This heat treatment significantly reduced gmin in L. decidua but it was not significant in P. abies. In both species, exposure to heat induced an increase in cuticle thickness, as well as provoking species-specific microchemical responses. Lignification of the middle lamella in L. decidua revealed a heat-acclimative potential that likely contributed to reduced cuticular water loss. In P. abies, despite an obvious increase in cuticle thickness, no significant acclimative change was seen in gmin. Flavonoids (kaempferol) were detected throughout the cuticle and outer cell wall of both species, but their contribution to reduced gmin is still unresolved. Our results demonstrate that cuticle and cell wall changes in conifer seedlings are species-specific and trait-dependent, and they highlight the role of epidermal chemistry in shaping resilience to climate warming at the alpine treeline.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13358877/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148220012","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":"Good neighbours: current-year needles in Nordmann fir rely on their 1-year-old neighbouring needles for adequate nutrient supply.","authors":"Sylwia Głazowska, Helle J Martens, Bjarke Veierskov, Daniel P Persson","doi":"10.1093/treephys/tpag064","DOIUrl":"10.1093/treephys/tpag064","url":null,"abstract":"<p><p>The annual transport patterns of mineral nutrients in conifers remain poorly understood. Calcium (Ca) and magnesium (Mg) deficiencies often occur in planted conifer stands and cannot be easily remedied by simply adding these nutrients to soil. This study examined translocation and remobilization of Ca and Mg in young Nordmann fir (Abies nordmanniana) trees. Our data revealed that Ca and Mg absorbed by the roots do not reach the needles during the current growth season, indicating that internal nutrient remobilization is crucial for the growth of new needles, particularly shortly after the budbreak. Monitoring 1-year-old needles over a full annual cycle revealed steep declines in Ca and Mg around budbreak, coinciding with their increase in the emerging needles on the same branch. This strongly suggests that older needles supply Ca and Mg to new needles. Trees with low Mg concentration in 1-year-old needles in the spring developed visual Mg deficiency symptoms during the summer. For Ca, which is immobile in the phloem, we recorded a substantial increase in the apoplast of older needles just before budbreak. Simultaneously, the immunolocalization of cell wall homogalacturonan in these needles declined, suggesting pectin modification that facilitates Ca release from cell walls, enabling its translocation to the neighbouring, current-year needles. Our findings reveal a previously unknown process that advances understanding of mineral nutrient remobilization in conifer trees.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13358879/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148340329","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":"Physiological and molecular responses of poplar to drought stress and functional analysis of the key factor PagJAZ12B in JA signal transduction to drought tolerance.","authors":"Li Huijiao, Qi Siyue, Su Riqin, Yao Tongtong, Bi Chenxu, Yang Meijian, Zhang Yingyue, Ao Hong, Ding Changjun, Zhang Huihui","doi":"10.1093/treephys/tpag076","DOIUrl":"10.1093/treephys/tpag076","url":null,"abstract":"<p><p>Identifying key genes involved in drought tolerance and clarifying their molecular mechanisms are crucial for breeding drought-tolerant poplar varieties. In this study, Populus alba × Populus glandulosa `84 K' was used as the experimental material to analyze its physiological and molecular responses to different levels of drought stress. Key drought-responsive genes were identified by weighted gene co-expression network analysis, and their functional roles were further validated. The results showed that drought significantly inhibited poplar growth, and both photosynthetic damage and oxidative damage in leaves increased with the severity of stress. RNA-seq analysis revealed that the differentially expressed genes in poplar leaves under drought stress were not only significantly enriched in photosynthesis and antioxidant-related pathways, but also enriched in plant hormone signal transduction and α-linolenic acid metabolism pathways, suggesting that jasmonic acid (JA) signaling plays a role in regulating the drought response of poplar. Based on the combined analysis of RNA-seq and weighted gene co-expression network analysis, PagJAZ12B was identified as a key gene. The overexpression lines of PagJAZ12B showed higher sensitivity to drought, as indicated by stronger inhibition of photosynthesis and more severe oxidative damage. In conclusion, the repressor gene PagJAZ12B in the JA signaling pathway negatively regulates drought tolerance in poplar, indicating that activation of the JA signaling pathway plays a positive role in the drought response of poplar. These findings provide important gene targets and a theoretical basis for improving drought tolerance in poplar through molecular breeding and for developing stress-resistant forestry varieties.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148139076","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":"Foliar structural and physiological responses of young Picea abies trees to elevated environmental humidity.","authors":"Arne Sellin, Katrin Heinsoo, Taavi Reinthal, Eele Õunapuu-Pikas","doi":"10.1093/treephys/tpag087","DOIUrl":"10.1093/treephys/tpag087","url":null,"abstract":"<p><p>Climate change affects the physiology and growth of trees, as well as the functioning, health and productivity of forest ecosystems. This also concerns forests dominated by Norway spruce (Picea abies (L.) Karst.), one of the most important tree species in Europe, in both economic and ecological aspects. In the southern part of its range, the growth of spruce trees will be primarily constrained by limited soil water and high atmospheric vapor pressure deficit in the future. However, there is little information on how the trees will respond to increasing precipitation and the concomitant rise in environmental humidity, predicted for high latitudes. In this article, we evaluated the effects of increasing environmental humidity (soil vs atmospheric humidity) on needle morphology, water status and gas exchange in trees in a northern climate, aiming to understand the reasons for the growth decline in response to elevated air humidity revealed in our previous studies. A 15% increase in summer precipitation and the associated change in soil moisture do not considerably affect trees' performance in northern mesic conditions. Growing in increased air humidity (relative humidity elevated by ~5%) did not influence photosynthetic capacity, but it increased the light compensation point of photosynthesis (19.7 → 31.4 μmol m-2 s-1) and dark respiration rate (-0.216 → -0.297 μmol m-2 s-1) of the spruce trees. In light of climate change, both responses reduce photosynthetic output, increasing respiratory losses and reducing the growth potential of trees.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148303125","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":"Mind the vessel-revisited: integrating xylogenesis, wood anatomy and tree physiology in a changing climate.","authors":"Daniel M Johnson, Jean-Christophe Domec","doi":"10.1093/treephys/tpag081","DOIUrl":"10.1093/treephys/tpag081","url":null,"abstract":"","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148240419","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":"Stem dehydration, more than hydraulic failure, drives drought mortality in conifer seedlings with contrasting hydraulic vulnerability.","authors":"Hisanori Harayama, Kenichi Yazaki, Mitsutoshi Kitao","doi":"10.1093/treephys/tpag079","DOIUrl":"10.1093/treephys/tpag079","url":null,"abstract":"<p><p>Climate change is intensifying drought frequency and severity, threatening forest regeneration and survival in many parts of the world. To elucidate the mechanisms underlying drought-induced mortality in conifer seedlings, we compared Japanese larch (Larix kaempferi (Lamb.) Carrière) and Sakhalin fir (Abies sachalinensis (F. Schmidt) Mast.), two major afforestation species with contrasting stem hydraulic vulnerability distributed in cool-temperate northern Japan. We combined measurements of hydraulic traits with a soil-drying experiment using potted seedlings, monitoring plant-water relations, gas exchange, non-structural carbohydrates and survival after rewatering. Compared with fir, larch exhibited higher maximum stem conductivity (Kstem) but greater cavitation vulnerability, with 50% loss (P50) occurring at -3.26 MPa, whereas in fir this occurred at -5.89 MPa. In both species, stomata closed before turgor loss or onset of hydraulic failure, and photosynthesis ceased well before seedling death. Non-structural carbohydrate concentrations remained stable, with starch converted to soluble sugars, indicating mobilization for osmotic regulation and metabolic maintenance rather than carbon starvation. In fir, seedling mortality occurred at a lethal water potential (Ψlethal) of -5.50 MPa, which coincided with ~80% loss of stem relative water content (RWC) despite substantial conductivity being retained, pointing to tissue desiccation as the primary cause of mortality. In larch, mortality (Ψlethal: -4.40 MPa) coincided with both ~80% loss of stem RWC and Kstem, indicating the co-occurrence of severe dehydration and loss of hydraulic function at death. In these two species exhibiting different traits related to stem vulnerability, lethal drought thresholds were more consistently predicted by stem RWC than by hydraulic metrics alone. Stem RWC therefore provides a robust integrative indicator of drought-induced mortality risk in conifer seedlings.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148164492","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":"Frequency-dependent climate sensitivity of sub-daily radial growth of tree stems at the dry Arctic treeline.","authors":"Jan Tumajer, Håkan Grudd, Hana Kuželová, Jelena Lange, Václav Treml","doi":"10.1093/treephys/tpag068","DOIUrl":"10.1093/treephys/tpag068","url":null,"abstract":"<p><p>Radial growth of tree stems shows remarkable variability over the year but also within individual days. Understanding the frequency-dependent growth sensitivity, i.e., the shifting responses of wood formation to meteorological conditions between annual and daily temporal scales, is essential for predicting forest growth under future climates. However, this knowledge is limited for the cold Arctic margins of species distribution. To address this gap, we monitored intra-annual and sub-daily stem radius variation of Pinus sylvestris L. for 2 years using xylogenesis microsampling and dendrometers at the cold-dry treeline beyond the Arctic Circle near Abisko, Northern Sweden. Using linear statistics, cell growth modeling and wavelet transformation, we separated individual frequencies of stem oscillations, ranked their statistical importance and identified immediate and lagged meteorological drivers of stem radius increment. Radial growth of tree stems showed overlapping oscillations at annual and daily frequencies. On an annual scale, radial growth and cell production peaked during the warm summer months. However, within the summer, stem radius increment accelerated toward the cool, moist midnight hours and ceased during the day as the temperature and solar altitude increased. Accordingly, we identified two growth-optimal intervals with peak growth rates, jointly accounting for 68% of the total growth: (i) an air temperature of 8-16 °C with a vapor pressure deficit (VPD) of <0.2 kPa, and (ii) an air temperature of 4-16 °C and VPD = 0 kPa. While correlations between peak-summer growth rates and immediate temperature and VPD were negative, these correlations switched to positive when considering lagged meteorological variables preceding growth by up to 4 days. Our results suggest frequency-dependent shifts and lagged responses of radial growth to meteorological variables at the Arctic treeline, particularly for air temperature and humidity. We propose that the midday growth reduction during summer may help explain non-linear responses of northern boreal forests to recent climate warming.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13330539/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147975750","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}