Tree physiology最新文献

{"title":"Moisture stress limits radial mixing of non-structural carbohydrates in sapwood of trembling aspen.","authors":"Drew M P Peltier, Phiyen Nguyen, Chris Ebert, George W Koch, Edward A G Schuur, Kiona Ogle","doi":"10.1093/treephys/tpad083","DOIUrl":"10.1093/treephys/tpad083","url":null,"abstract":"<p><p>Dynamics in non-structural carbohydrate (NSC) pools may underlie observed drought legacies in tree growth. We assessed how aridity influences the dynamics of different-aged NSC pools in tree sapwood at two sites with differing climate conditions ('wet' vs 'dry'), which also experienced widespread regional drought 5 years earlier. We used an incubation method to measure the radiocarbon (Δ14C) in CO2 respired from Populus tremuloides Michx. (aspen) tree rings to evaluate NSC storage and mixing patterns, coupled with measurements of NSC (soluble sugars and starch) concentrations and respired δ13C-CO2. At a wet site, CO2 respired from rings formed during 1962-67 was only ~11 years old, suggesting deep sapwood mixing of NSCs as starch. At a dry site, the total NSC was about one-third of wet-site totals, maximum ages in deep rings were lower and ages more rapidly increased in shallow rings and then plateaued. These results suggest historically shallower mixing and/or relatively higher consumption of NSCs under dry conditions. Both sites, however, had similar aged NSC (<1 year) in the most recent six rings, indicative of deep radial mixing following relatively wet conditions during the sampling year. We suggest that the significant differences in NSC mixing among sites are driven by moisture stress, where aridity reduces NSC reserves and restricts the depth of radial mixing. However, dynamic climate conditions in the south-western USA resulted in more complex radial patterns of sapwood NSC age than previously described. We suggest a novel conceptual framework to understand how moisture variability might influence the dynamics of NSC mixing in the sapwood.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"204-216"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9696899","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":"Tropical forest lianas have greater non-structural carbohydrate concentrations in the stem xylem than trees.","authors":"Caroline Signori-Müller, David Galbraith, Julia V Tavares, Simone M Reis, Francisco C Diniz, Martin Gilpin, Beatriz S Marimon, Geertje M F van der Heijden, Camila Borges, Bruno B L Cintra, Sarah Mião, Paulo S Morandi, Alex Nina, Carlos A Salas Yupayccana, Manuel J Marca Zevallos, Eric G Cosio, Ben H Marimon Junior, Abel M Mendoza, Oliver Phillips, Norma Salinas, Rodolfo Vasquez, Maurizio Mencuccini, Rafael S Oliveira","doi":"10.1093/treephys/tpad096","DOIUrl":"10.1093/treephys/tpad096","url":null,"abstract":"<p><p>Lianas (woody vines) are important components of tropical forests and are known to compete with host trees for resources, decrease tree growth and increase tree mortality. Given the observed increases in liana abundance in some forests and their impacts on forest function, an integrated understanding of carbon dynamics of lianas and liana-infested trees is critical for improved prediction of tropical forest responses to climate change. Non-structural carbohydrates (NSC) are the main substrate for plant metabolism (e.g. growth, respiration), and have been implicated in enabling tree survival under environmental stress, but little is known of how they vary among life-forms or of how liana infestation impacts host tree NSC. We quantified stem xylem total NSC concentrations and its fractions (starch and soluble sugars) in trees without liana infestation, trees with ˃50% of the canopy covered by lianas, and the lianas infesting those trees. We hypothesized that (i) liana infestation depletes NSC storage in host trees by reducing carbon assimilation due to competition for resources; (ii) trees and lianas, which greatly differ in functional traits related to water transport and carbon uptake, would also have large differences in NSC storage. As water availability has a significant role in NSC dynamics of Amazonian tree species, we tested these hypotheses within a moist site in western Amazonia and a drier site in southern Amazonia. We did not find any difference in NSC, starch or soluble sugar concentrations between infested and non-infested trees, in either site. This result suggests that negative liana impact on trees may be mediated through mechanisms other than depletion of host tree NSC concentrations. We found lianas have higher stem NSC and starch than trees in both sites. The consistent differences in starch concentrations, a long-term NSC reserve, between life forms across sites reflect differences in lianas and trees carbon gain and use. Soluble sugar concentrations were higher in lianas than in trees in the moist site but indistinguishable between life forms in the dry site. The lack of difference in soluble sugars between trees and lianas in the dry site emphasizes the importance of this NSC fraction for the metabolism of plants occurring in water limited environments. Abstracts in Portuguese and Spanish are available in the supplementary material.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"159-172"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10061619","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":"Saving for an emergency: how does carbon storage contribute to tree survival under long-term stress?","authors":"Honglang Duan, Simon M Landhäusser, Shengnan Ouyang, David T Tissue","doi":"10.1093/treephys/tpae025","DOIUrl":"10.1093/treephys/tpae025","url":null,"abstract":"","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"186-191"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139933037","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":"Carbon use strategies in shoot and acorn growth of two evergreen broadleaf trees unraveled by seasonal carbohydrate measurements and carbon isotope analysis.","authors":"Qingmin Han, Daisuke Kabeya, Yoshiyuki Inagaki, Tatsuro Kawasaki, Akiko Satake","doi":"10.1093/treephys/tpad072","DOIUrl":"10.1093/treephys/tpad072","url":null,"abstract":"<p><p>Woody species have evolved carbon (C) storage processes that meet needs for reserves associated with asynchronies between C supply and demand. However, our understanding of storage dynamics is still elusive in mature trees, especially when reproduction is involved. Integrated analyses of isotope ratios, concentrations and biomass may enhance understanding of stored C fractions' dynamics and roles. Thus, we monitored starch and soluble sugars (SSs), C isotope ratios and biomass, in leaves, twigs and reproductive organs of two mature evergreen broadleaf trees, Quercus glauca Thumb. and Lithocarpus edulis Nakai, for 2 years. During the growing season, no starch was observed in twigs, while constant starch levels were observed in leaves. Increase in SSs for winter hardening was earlier in L. edulis than in Q. glauca, in line with L. edulis acorns' earlier ripening. Decrease in SSs and increase in starch occurred simultaneously in the next spring. In addition, sucrose accounted for <10% of total SSs in leaves of both species, whereas mannose accounted for up to 75% in Q. glauca and myo-inositol up to 23% in L. edulis, indicating species-specific sugar composition. These results indicate that seasonal variation of SSs fraction was more reflective of climatic change and nonstructural carbohydrate storage was less influenced by reproduction. No starch was detected in acorn organs of either Q. glauca or L. edulis except in ripening seeds. The biomass of ripe acorns was 1.7- and 6.4-fold greater than that of current-year twigs in Q. glauca and L. edulis, respectively. Bulk twigs and reproductive organs were ca 1.0‰ 13C enriched relative to bulk leaves, which was lower than in deciduous trees. These results indicate that a new photo-assimilate is the predominant C source for reproductive growth. These findings provide new insights into the dynamics of C storage in relation to reproduction in evergreen broadleaf trees.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"221-231"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9493435","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":"Upside down and the game of C allocation.","authors":"Negar Rezaie, Ettore D'Andrea, Andrea Scartazza, Jožica Gričar, Peter Prislan, Carlo Calfapietra, Alberto Battistelli, Stefano Moscatello, Simona Proietti, Giorgio Matteucci","doi":"10.1093/treephys/tpad034","DOIUrl":"10.1093/treephys/tpad034","url":null,"abstract":"<p><p>Non-structural carbohydrates (NSCs) represent the primary carbon (C) reserves and play a crucial role in plant functioning and resilience. Indeed, these compounds are involved in the regulation between C supply and demand, and in the maintenance of hydraulic efficiency. Non-structural carbohydrates are stored in parenchyma of woody organs, which is recognized as a proxy for reserve storage capacity of tree. Notwithstanding the importance of NSCs for tree physiology, their long-term regulation and trade-offs against growth were not deeply investigated. This work evaluated the long-term dynamics of mature tree reserves in stem and root, proxied by parenchyma features and focusing on the trade-off and interplay between the resources allocation in radial growth and reserves in stem and coarse root. In a Mediterranean beech forest, NSCs content, stem and root wood anatomy analysis and eddy covariance data were combined. The parenchyma fraction (RAP) of beech root and stem was different, due to differences in axial parenchyma (AP) and narrow ray parenchyma (nRP) fractions. However, these parenchyma components and radial growth showed synchronous inter-annual dynamics between the two organs. In beech stem, positive correlations were found among soluble sugars content and nRP and among starch content and the AP. Positive correlations were found among Net Ecosystem Exchange (NEE) and AP of both organs. In contrast, NEE was negatively correlated to radial growth of root and stem. Our results suggest a different contribution of stem and roots to reserves storage and a putative partitioning in the functional roles of parenchyma components. Moreover, a long-term trade-off of C allocation between growth and reserve pool was evidenced. Indeed, in case of C source reduction, trees preferentially allocate C toward reserves pool. Conversely, in high productivity years, growth represents the major C sink.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"192-203"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9111281","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":"Tracing carbon and nitrogen reserve remobilization during spring leaf flush and growth following defoliation.","authors":"Ashley T Hart, Simon M Landhäusser, Erin Wiley","doi":"10.1093/treephys/tpae015","DOIUrl":"10.1093/treephys/tpae015","url":null,"abstract":"<p><p>Woody plants rely on the remobilization of carbon (C) and nitrogen (N) reserves to support growth and survival when resource demand exceeds supply at seasonally predictable times like spring leaf flush and following unpredictable disturbances like defoliation. However, we have a poor understanding of how reserves are regulated and whether distance between source and sink tissues affects remobilization. This leads to uncertainty about which reserves-and how much-are available to support plant functions like leaf growth. To better understand the source of remobilized reserves and constraints on their allocation, we created aspen saplings with organ-specific labeled reserves by using stable isotopes (13C,15N) and grafting unlabeled or labeled stems to labeled or unlabeled root stocks. We first determined which organs had imported root or stem-derived C and N reserves after spring leaf flush. We then further tested spatial and temporal variation in reserve remobilization and import by comparing (i) upper and lower canopy leaves, (ii) early and late leaves, and (iii) early flush and re-flush leaves after defoliation. During spring flush, remobilized root C and N reserves were preferentially allocated to sinks closer to the reserve source (i.e., lower vs upper canopy leaves). However, the reduced import of 13C in late versus early leaves indicates reliance on C reserves declined over time. Following defoliation, re-flush leaves imported the same proportion of root N as spring flush leaves, but they imported a lower proportion of root C. This lower import of reserve C suggests that, after defoliation, leaf re-flush rely more heavily on current photosynthate, which may explain the reduced leaf mass recovery of re-flush canopies (31% of initial leaf mass). The reduced reliance on reserves occurred even though roots retained significant starch concentrations (~5% dry wt), suggesting that aspen prioritizes the maintenance of root reserves at the expense of fast canopy recovery.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"145-157"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139569706","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":"Season of drought affects growth, but not nonstructural carbohydrates dynamics, in Pinus taeda saplings.","authors":"Scott W Oswald, Doug P Aubrey","doi":"10.1093/treephys/tpae014","DOIUrl":"10.1093/treephys/tpae014","url":null,"abstract":"<p><p>In temperate evergreen conifers, growth occurs mostly in summer but photosynthesis proceeds year-round; thus, nonstructural carbohydrates (NSCs) increase in winter but decrease in summer. Given that mild drought reduces growth but not photosynthesis, a drought in summer should increase NSCs more than one in winter. However, the active regulation hypothesis suggests that to increase future drought resilience, plants might downregulate growth to increase NSCs after a winter drought even if NSCs do not increase during the drought. To test whether this is so, potted Pinus taeda saplings (age $<kern-3pt1$ year) were subjected to 6-month droughts in a greenhouse with one treatment receiving drought during winter (September-March), and another during summer (March-September). Both treatments were compared with a control. To measure dry biomass and NSCs, we harvested plants monthly following each drought, while to assess changes in growth rates, we measured height and diameter monthly. While we observed seasonal variation and an overall increase during the study, we found no drought-related changes in NSC dynamics; however, drought did reduce growth. Furthermore, drought in winter did reduce growth during the following summer, but the reduction was less than for a drought in summer. We conclude that the effect of drought on NSCs was too small to detect in our plants. While better control of soil water would have reduced a major source of uncertainty, plants with larger NSC reserves or more intense stress would also yield easier-to-detect effects. Although not definitive, our results suggest that water stress does not lead to dramatic changes in seasonal NSC dynamics in its aftermath, despite what one might expect under the active regulation hypothesis.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"119-133"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139672780","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":"Modulation of polar auxin transport identifies the molecular determinants of source-sink carbon relationships and sink strength in poplar.","authors":"Vimal K Balasubramanian, Albert Rivas-Ubach, Tanya Winkler, Hugh Mitchell, James Moran, Amir H Ahkami","doi":"10.1093/treephys/tpad073","DOIUrl":"10.1093/treephys/tpad073","url":null,"abstract":"<p><p>Source-to-sink carbon (C) allocation driven by the sink strength, i.e., the ability of a sink organ to import C, plays a central role in tissue growth and biomass productivity. However, molecular drivers of sink strength have not been thoroughly characterized in trees. Auxin, as a major plant phytohormone, regulates the mobilization of photoassimilates in source tissues and elevates the translocation of carbohydrates toward sink organs, including roots. In this study, we used an 'auxin-stimulated carbon sink' approach to understand the molecular processes involved in the long-distance source-sink C allocation in poplar. Poplar cuttings were foliar sprayed with polar auxin transport modulators, including auxin enhancers (AE) (i.e., IBA and IAA) and auxin inhibitor (AI) (i.e., NPA), followed by a comprehensive analysis of leaf, stem and root tissues using biomass evaluation, phenotyping, C isotope labeling, metabolomics and transcriptomics approaches. Auxin modulators altered root dry weight and branching pattern, and AE increased photosynthetically fixed C allocation from leaf to root tissues. The transcriptome analysis identified highly expressed genes in root tissue under AE condition including transcripts encoding polygalacturonase and β-amylase that could increase the sink size and activity. Metabolic analyses showed a shift in overall metabolism including an altered relative abundance levels of galactinol, and an opposite trend in citrate levels in root tissue under AE and AI conditions. In conclusion, we postulate a model suggesting that the source-sink C relationships in poplar could be fueled by mobile sugar alcohols, starch metabolism-derived sugars and TCA-cycle intermediates as key molecular drivers of sink strength.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"82-101"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11898627/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9560311","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":"Dynamical systems for plant carbon storage: describing complex reserve dynamics from simple fluctuations in photosynthesis and carbon allocation.","authors":"R Alex Thompson, Simon M Landhäusser, Henry D Adams","doi":"10.1093/treephys/tpad104","DOIUrl":"10.1093/treephys/tpad104","url":null,"abstract":"","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"28-33"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10114232","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":"Optimal carbon storage during drought.","authors":"Elisa Z Stefaniak, David T Tissue, Roderick C Dewar, Belinda E Medlyn","doi":"10.1093/treephys/tpae032","DOIUrl":"10.1093/treephys/tpae032","url":null,"abstract":"<p><p>Allocation of non-structural carbohydrates to storage allows plants to maintain a carbon pool in anticipation of future stress. However, to do so, plants must forego use of the carbon for growth, creating a trade-off between storage and growth. It is possible that plants actively regulate the storage pool to maximize fitness in a stress-prone environment. Here, we attempt to identify the patterns of growth and storage that would result during drought stress under the hypothesis that plants actively regulate carbon storage. We use optimal control theory to calculate the optimal allocation to storage and utilization of stored carbon over a single drought stress period. We examine two fitness objectives representing alternative life strategies: prioritization of growth and prioritization of storage, as well as the strategies in between these extremes. We find that optimal carbon storage consists of three discrete phases: 'growth', 'storage without growth' and the 'stress' phase where there is no carbon source. This trajectory can be defined by the time point when the plant switches from growth to storage. Growth-prioritizing plants switch later and fully deplete their stored carbon over the stress period, while storage-prioritizing plants either do not grow or switch early in the drought period. The switch time almost always occurs before the soil water is depleted, meaning that growth stops before photosynthesis. We conclude that the common observation of increasing carbon storage during drought could be interpreted as an active process that optimizes plant performance during stress.</p>","PeriodicalId":23286,"journal":{"name":"Tree physiology","volume":" ","pages":"34-45"},"PeriodicalIF":3.5,"publicationDate":"2024-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11898659/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140159119","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}