{"title":"Comprehensive analysis of class III peroxidase genes revealed PePRX2 enhanced lignin biosynthesis and drought tolerance in Phyllostachys edulis.","authors":"Yuhan Jia, Mengyun Li, Jing Xu, Shuxin Chen, Xiaojiao Han, Wenmin Qiu, Zhuchou Lu, Renying Zhuo, Guirong Qiao","doi":"10.1093/treephys/tpaf008","DOIUrl":"10.1093/treephys/tpaf008","url":null,"abstract":"<p><p>Class III peroxidase (PRX) is the key enzyme in lignin biosynthesis and critical for maintaining the redox balance in plants to respond to stress. In moso bamboo (Phyllostachys edulis), a globally significant non-timber forestry species, the potential roles of PRX genes remain largely unknown. In this research, a total of 179 PePRXs was identified on a genome-wide scale in moso bamboo. Phylogenic relationship, conserved motifs, gene structure, collinearity and cis-acting elements were investigated. Analysis of gene expression indicated that PePRXs exhibited tissue-specific expression and different response patterns to hormones and abiotic stresses. Based on the transcriptome data, 10 PePRXs with positive correlations between expression levels and lignification degree were screened out. Among them, PePRX2 was selected as a candidate gene according to the co-expression network. Y1H and Dual-Luc assays demonstrated that PeMYB61 could bind to the promoter of PePRX2 and enhance its transcription. The result of in situ hybridization showed that PePRX2 was specifically expressed in the vascular bundle sheath cells of bamboo shoot. As a secreted protein, PePRX2 was located on the cell wall. Overexpression of PePRX2 led to a significant increase in lignin content in transgenic poplar, indicating that PePRX2 could promote lignin polymerization. In comparison with the WT, the PePRX2-OE poplar lines exhibited increased peroxidase activity and decreased levels of MDA, O2- and H2O2 under drought stress, indicating enhanced drought resistance. This thorough analysis of the PRX family in moso bamboo provided new insight into the roles of PePRXs in lignin biosynthesis and drought adaptation.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143075563","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":"Constitutive chemical defense mechanism of inner bark of Sorbus commixta against Trametes versicolor.","authors":"Masato Koyama, Kengo Shigetomi, Yutaka Tamai, Keita Arakawa, Yuzou Sano","doi":"10.1093/treephys/tpaf006","DOIUrl":"10.1093/treephys/tpaf006","url":null,"abstract":"<p><p>Tree bark is a crucial tissue that defends tree stems from invasions by microorganisms. However, our understanding of the constitutive chemical defense mechanisms of the tree barks remains limited. Our group recently discovered that the inner bark of Sorbus commixta Hedl. exhibited potent inhibitory effects on the growth of the white-rot fungus, Trametes versicolor (Linnaeus) Lloyd. It was hypothesized that this growth suppression was due to hydrogen cyanide (HCN) originating from cyanogenic glycosides such as amygdalin and prunasin, which are secondary metabolites in the inner bark of S. commixta. To test this hypothesis, we first quantified the amygdalin content in the inner bark of S. commixta and evaluated the antifungal activity (AFA) of HCN against T. versicolor by placing paper discs on potato dextrose agar with T. versicolor. Subsequently, we identified HCN in the inner bark of S. commixta using a picric acid paper. In the AFA tests, the amygdalin + β-glucosidase solution, the potassium cyanide (KCN) + benzaldehyde solution and the KCN solution exhibited elevated AFA against T. versicolor. Conversely, the amygdalin solution, the β-glucosidase solution and the benzaldehyde solution did not exhibit significant AFA. These findings demonstrate that HCN acts as an antifungal agent against T. versicolor. Furthermore, HCN was detected in the freeze-dried inner bark pieces and the trunks of living S. commixta. This suggests that the disruption of the cells in the inner bark of S. commixta caused the cyanogenic glycosides and β-glucosidase to interact, which resulted in the hydrolysis of cyanogenic glycosides and generation of HCN. From the perspective of constitutive chemical defense mechanisms, HCN plays a crucial role in the high AFA of the inner bark of S. commixta against T. versicolor, creating an unfavorable environment for the growth of white-rot fungus after injury breaches the periderm.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142972277","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}
Tree physiologyPub Date : 2025-02-03DOI: 10.1093/treephys/tpae168
Peter Fransson, Hyungwoo Lim, Peng Zhao, Pantana Tor-Ngern, Matthias Peichl, Hjalmar Laudon, Nils Henriksson, Torgny Näsholm, Oskar Franklin
{"title":"An eco-physiological model of forest photosynthesis and transpiration under combined nitrogen and water limitation.","authors":"Peter Fransson, Hyungwoo Lim, Peng Zhao, Pantana Tor-Ngern, Matthias Peichl, Hjalmar Laudon, Nils Henriksson, Torgny Näsholm, Oskar Franklin","doi":"10.1093/treephys/tpae168","DOIUrl":"10.1093/treephys/tpae168","url":null,"abstract":"<p><p>Although the separate effects of water and nitrogen (N) limitations on forest growth are well known, the question of how to predict their combined effects remains a challenge for modeling of climate change impacts on forests. Here, we address this challenge by developing a new eco-physiological model that accounts for plasticity in stomatal conductance and leaf N concentration. Based on optimality principle, our model determines stomatal conductance and leaf N concentration by balancing carbon uptake maximization, hydraulic risk and cost of maintaining photosynthetic capacity. We demonstrate the accuracy of the model predictions by comparing them against gross primary production estimates from eddy covariance flux measurements and sap-flow measurement scaled canopy transpiration in a long-term fertilized and an unfertilized Scots pine (Pinus sylvestris L.) forest in northern Sweden. The model also explains the response to N fertilization as a consequence of (i) reduced carbon cost of N uptake and (ii) increased leaf area per hydraulic conductance. The results suggest that leaves optimally coordinate N concentration and stomatal conductance both on short (weekly) time scales in response to weather conditions and on longer time scales in response to soil water and N availabilities.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142955630","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}
Tree physiologyPub Date : 2025-02-03DOI: 10.1093/treephys/tpaf005
Robert Brandon Pratt
{"title":"Surviving on the edge: drought resistance strategies among desert shrubs.","authors":"Robert Brandon Pratt","doi":"10.1093/treephys/tpaf005","DOIUrl":"10.1093/treephys/tpaf005","url":null,"abstract":"","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142984918","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}
Tree physiologyPub Date : 2025-02-03DOI: 10.1093/treephys/tpaf007
Graham J Dow, Noa Kekuewa Lincoln, Dolly Autufuga, Robert Paull
{"title":"From forests to farming: identification of photosynthetic limitations in breadfruit across diverse environments.","authors":"Graham J Dow, Noa Kekuewa Lincoln, Dolly Autufuga, Robert Paull","doi":"10.1093/treephys/tpaf007","DOIUrl":"10.1093/treephys/tpaf007","url":null,"abstract":"<p><p>Breadfruit (Artocarpus altilis (Parkinson) Fosberg) is a prolific tropical tree producing highly nutritious and voluminous carbohydrate-rich fruits. Already recognized as an underutilized crop of high potential, breadfruit could ameliorate food insecurity and protect against climate-related productivity shocks in undernourished equatorial regions. However, a lack of fundamental knowledge impedes widespread agricultural adoption, from modern agroforestry to plantation schemes. Here, we used a multi-environment breadfruit variety trial across the Hawaiian Islands to determine photosynthetic limitations, understand the role of site conditions or varietal features, and define their contributions to agronomic efficiency. Photosynthetic rates were dependent on location and variety, and strongly correlated with fruit yield (r2 = 0.80, P < 0.001). Photochemistry was suitable to full-sunlight conditions, with a saturation point of 1545 photosynthetically active radiation, Vcmax of 151 μmol m-2 s-1 and Jmax of 128 μmol m-2 s-1, which are high-end compared with other tropical and temperate tree crops. However, limitations on CO2 assimilation were imposed by stomatal characteristics, including stomatal density (P < 0.05) and diurnal oscillations of stomatal conductance (>50% reductions from daily maxima). These constraints on CO2 diffusion are likely to limit maximum productivity more than photochemistry. Our results comprise the first comprehensive analysis of breadfruit photosynthesis, successfully link ecophysiology with fruit yield, and identify vital traits for future research and management optimization.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143012420","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":"Metabolomic and proteomic changes in leaves of rubber seedlings infected by Phytophthora palmivora.","authors":"Pongsakorn Kruaweangmol, Kitiya Ekchaweng, Sumallika Morakul, Narumon Phaonakrop, Sittiruk Roytrakul, Paiboon Tunsagool","doi":"10.1093/treephys/tpaf010","DOIUrl":"10.1093/treephys/tpaf010","url":null,"abstract":"<p><p>Phytophthora palmivora, an oomycete pathogen, induces leaf fall disease in rubber trees (Hevea brasiliensis), causing significant economic losses. Effective disease management requires an understanding metabolic dynamics during infection. This study employed untargeted metabolomic and proteomic analyses to investigate the response of rubber seedling leaves to P. palmivora infection. Metabolomic profiling revealed 1702 and 979 metabolite peaks in positive and negative ionization modes, respectively, with 212 metabolites identified after duplicate removal. Principal component analysis demonstrated distinct metabolic profiles between infected and non-infected leaves. Volcano plots indicated significant changes in 90 metabolites (P < 0.05, fold-change ≥ 2), with 20 showing increased levels and 70 showing decreased levels in infected leaves. Pathway analysis highlighted nine metabolic pathways, with alanine, aspartate, and glutamate metabolism being the most impacted. Proteomic analysis identified 391 proteins, with 283 in infected leaves and 253 in control leaves. Among these, 145 were common to both conditions, suggesting their roles in maintaining homeostasis and responding to stress. Unique proteins in infected leaves were linked to oxidative phosphorylation, ATP synthesis and metabolic adjustments, reflecting the increased energy demands. Control samples showed proteins related to growth and photosynthesis. Integrating metabolomic and proteomic data revealed significant alterations in energy metabolism pathways in response to infection. These findings enhance our understanding of rubber seedlings' defense strategies against P. palmivora, with implications for improving plant resistance and disease management strategies.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143053207","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}
Tree physiologyPub Date : 2025-02-03DOI: 10.1093/treephys/tpaf019
{"title":"Correction to: Tree growth strategies mediate drought resistance in species-diverse forests.","authors":"","doi":"10.1093/treephys/tpaf019","DOIUrl":"https://doi.org/10.1093/treephys/tpaf019","url":null,"abstract":"","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":"45 2","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143392013","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}
Tree physiologyPub Date : 2025-01-25DOI: 10.1093/treephys/tpae159
Benton N Taylor
{"title":"Symbiotic nitrogen fixation in trees: patterns, controls and ecosystem consequences.","authors":"Benton N Taylor","doi":"10.1093/treephys/tpae159","DOIUrl":"10.1093/treephys/tpae159","url":null,"abstract":"<p><p>Symbiotic nitrogen fixation (SNF) represents the largest natural input of bioavailable nitrogen into the biosphere, impacting key processes spanning from local community dynamics to global patterns of nutrient limitation and primary productivity. While research on SNF historically focused largely on herbaceous and agricultural species, the past two decades have seen major advances in our understanding of SNF by tree species in forest and savanna communities. This has included important developments in the mathematical theory of SNF in forest ecosystems, experimental work on the regulators of tree SNF, broad observational analyses of tree N-fixer abundance patterns and increasingly process-based incorporation of tree SNF into ecosystem models. This review synthesizes recent work on the local and global patterns, environmental drivers and community and ecosystem effects of nitrogen-fixing trees in natural ecosystems. By better understanding the drivers and consequences of SNF in forests, this review aims to shed light on the future of this critical process and its role in forest functioning under changing climate, nutrient cycling and land use.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142808034","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}
Tree physiologyPub Date : 2025-01-25DOI: 10.1093/treephys/tpae170
Santiago González-Carrera, Alejandro Fernández-Fuentes, Alfonso Escudero, Ignacio García-Estévez, Montserrat Martínez-Ortega, Sonia Mediavilla
{"title":"Leaf traits and insect herbivory levels in two Mediterranean oaks and their hybrids through contrasting environmental gradients.","authors":"Santiago González-Carrera, Alejandro Fernández-Fuentes, Alfonso Escudero, Ignacio García-Estévez, Montserrat Martínez-Ortega, Sonia Mediavilla","doi":"10.1093/treephys/tpae170","DOIUrl":"10.1093/treephys/tpae170","url":null,"abstract":"<p><p>Insect herbivory has attracted enormous attention from researchers due to its effects on plant fitness. However, there remain questions such as what are the most important leaf traits that determine consumption levels, whether there are latitudinal gradients in herbivore pressure, or whether there are differences in susceptibility between hybrids and their parental species. In this work, we address all these issues in two species of Mediterranean Quercus (Quercus faginea subsp. faginea Lam. and Quercus pyrenaica Wild.) and their hybrids. Over 2 years, we analyzed leaf emergence and 11 leaf traits (biomechanical, chemical and morphological), as well as the levels of herbivory by insects in leaves of the three genetic groups in different locations distributed along a climatic gradient. The hybrids showed intermediate values between both species in leaf emergence, chemical traits and structural reinforcement. By contrast, they were more similar to Q. faginea in leaf size and shape. Despite their intermediate leaf traits, hybrids always showed lower losses by consumption than both parental species, which suggests that they possess inherent higher resistance to herbivores, which cannot be explained by their dissimilarities in leaf traits. Within each genetic group, differences in leaf size were the most important determinant of differences in herbivory losses, which increased with leaf size. In turn, leaf size increased significantly with the increase in mean annual temperatures across the climatic gradient, in parallel with herbivory losses. In conclusion, contrary to our expectations, hybrids maintained lower levels of herbivory than their parent species. Given the potential negative effect of leaf herbivory on carbon fixation, this advantage of the hybrids would imply a threat to the persistence of both pure species. More research is needed to elucidate possible alternative mechanisms that allow for maintaining species integrity in the absence of reproductive barriers.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142898520","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":"Physiological and biochemical mechanisms of drought regulating the size and color of heartwood in Dalbergia odorifera.","authors":"Zhiyi Cui, Houzhen Hu, Xiaofei Li, Xiaojin Liu, Qilei Zhang, Zhou Hong, Ningnan Zhang, Wei Lin, Daping Xu","doi":"10.1093/treephys/tpae157","DOIUrl":"10.1093/treephys/tpae157","url":null,"abstract":"<p><p>Drought has been found to affect the size and color of precious heartwood of Dalbergia odorifera, but the mechanism remains unclear. For this purpose, we performed the measurement of heartwood size, color and flavonoid content and composition in a 15-year-old mixed plantation of D. odorifera and Santalum album that had been subjected to two levels of rainfall exclusion and control treatments for 7 years, and carbon isotope labeling and anatomical observation in 2-year-old potted D. odorifera seedlings exposed to two levels of drought and control treatments. The field experiment showed that drought had significant effects on heartwood size and color of D. odorifera. More starch was depleted in the transition zone (TZ) in drought than in control. Drought significantly decreased the values of color parameters and increased the contents of total flavonoids, glycitein, fisetin, chrysin and claussequinone, and total flavonoids, glycitein, fisetin, chrysin and claussequinone were significantly negatively correlated with L* and b*. The pot experiment showed that during longitudinal transport of nonstructural carbohydrate (NSC), the dilution factor of 13C abundance in the inner bark sap in severe drought (SD) was twice as much as that in control. The inner bark thickness and transverse area of sieve tubes in SD were significantly lower than those in control. Our findings further confirm that drought promotes the heartwood formation of D. odorifera, and discuss interspecific variations in the response of heartwood formation to drought. Drought enhances the exchange transport of NSC between phloem and xylem by reducing the transverse area of sieve tubes, thus causing more NSC to be transported into xylem, and drought also promotes the depletion of starch in the TZ to produce more heartwood. Drought darkens the heartwood color by increasing the contents of total flavonoids, glycitein, fisetin, chrysin and claussequinone in heartwood. To our knowledge, this is the first study addressing the physiological and biochemical mechanism of drought regulating heartwood formation.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142808119","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}