Santiago Trueba, Noelia González Muñoz, Régis Burlett, Laurent J. Lamarque, Yves Gibon, Teresa E. Gimeno, Aurore Kaisermann, Camille Benard, Cédric Lemaire, Jose M. Torres-Ruiz, Lisa Wingate, Sylvain Delzon
{"title":"淀粉耗竭率和水力衰竭率在干旱导致的秧苗死亡中都发挥了作用","authors":"Santiago Trueba, Noelia González Muñoz, Régis Burlett, Laurent J. Lamarque, Yves Gibon, Teresa E. Gimeno, Aurore Kaisermann, Camille Benard, Cédric Lemaire, Jose M. Torres-Ruiz, Lisa Wingate, Sylvain Delzon","doi":"10.1186/s13595-024-01246-7","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Key message</h3><p>The elapsed times to deplete starch concentrations and to reach a null hydraulic safety margin were related to tree seedling mortality under experimental drought. Starch concentration showed an accelerated decline across all species during the early stages of dehydration, while the concentrations of soluble sugars and total nonstructural carbohydrates remained stable. Concomitant carbohydrate depletion and hydraulic failure drive seedling mortality under drought.</p><h3 data-test=\"abstract-sub-heading\">Context</h3><p>Current upsurges of drought events are provoking impacts on tree physiology, resulting in forest mortality. Hydraulic dysfunction and nonstructural carbohydrate (NSC) depletion have been posited as the main mechanisms leading to plant mortality under drought.</p><h3 data-test=\"abstract-sub-heading\">Aims</h3><p>This study explores the dynamics of the two mortality-inducing processes during drought stress using an experimental approach with 12 evergreen tree species.</p><h3 data-test=\"abstract-sub-heading\">Methods</h3><p>Seedlings were subjected to drought until 100% mortality was observed. Midday (Ψ<sub>MD</sub>) and predawn (Ψ<sub>PD</sub>) water potentials, xylem pressure leading to a 50% loss of hydraulic conductivity (Ψ<sub>50</sub>), along with NSC concentrations in different organs (leaves, stems, and roots) were measured regularly during drought.</p><h3 data-test=\"abstract-sub-heading\">Results</h3><p>Total NSC concentrations and soluble sugar pools did not decline during drought. However, starch pools showed strong reductions early during drought stress as Ψ<sub>PD</sub> decreased, and the time leading to starch depletion emerged as a strong mortality predictor. Ψ<sub>50</sub> alone did not provide an accurate estimate of mortality, while the elapsed time to reach a null hydraulic safety margin (Ψ<sub>MD</sub>—Ψ<sub>50</sub> = 0) was related to seedling mortality.</p><h3 data-test=\"abstract-sub-heading\">Conclusion</h3><p>Adopting a dynamic approach by estimating the times to consume both starch reserves and hydraulic safety margins is highly relevant to improve predictions of tree mortality under the current context of increasing global drought.</p>","PeriodicalId":7994,"journal":{"name":"Annals of Forest Science","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The rates of starch depletion and hydraulic failure both play a role in drought-induced seedling mortality\",\"authors\":\"Santiago Trueba, Noelia González Muñoz, Régis Burlett, Laurent J. Lamarque, Yves Gibon, Teresa E. Gimeno, Aurore Kaisermann, Camille Benard, Cédric Lemaire, Jose M. Torres-Ruiz, Lisa Wingate, Sylvain Delzon\",\"doi\":\"10.1186/s13595-024-01246-7\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<h3 data-test=\\\"abstract-sub-heading\\\">Key message</h3><p>The elapsed times to deplete starch concentrations and to reach a null hydraulic safety margin were related to tree seedling mortality under experimental drought. Starch concentration showed an accelerated decline across all species during the early stages of dehydration, while the concentrations of soluble sugars and total nonstructural carbohydrates remained stable. Concomitant carbohydrate depletion and hydraulic failure drive seedling mortality under drought.</p><h3 data-test=\\\"abstract-sub-heading\\\">Context</h3><p>Current upsurges of drought events are provoking impacts on tree physiology, resulting in forest mortality. Hydraulic dysfunction and nonstructural carbohydrate (NSC) depletion have been posited as the main mechanisms leading to plant mortality under drought.</p><h3 data-test=\\\"abstract-sub-heading\\\">Aims</h3><p>This study explores the dynamics of the two mortality-inducing processes during drought stress using an experimental approach with 12 evergreen tree species.</p><h3 data-test=\\\"abstract-sub-heading\\\">Methods</h3><p>Seedlings were subjected to drought until 100% mortality was observed. Midday (Ψ<sub>MD</sub>) and predawn (Ψ<sub>PD</sub>) water potentials, xylem pressure leading to a 50% loss of hydraulic conductivity (Ψ<sub>50</sub>), along with NSC concentrations in different organs (leaves, stems, and roots) were measured regularly during drought.</p><h3 data-test=\\\"abstract-sub-heading\\\">Results</h3><p>Total NSC concentrations and soluble sugar pools did not decline during drought. However, starch pools showed strong reductions early during drought stress as Ψ<sub>PD</sub> decreased, and the time leading to starch depletion emerged as a strong mortality predictor. Ψ<sub>50</sub> alone did not provide an accurate estimate of mortality, while the elapsed time to reach a null hydraulic safety margin (Ψ<sub>MD</sub>—Ψ<sub>50</sub> = 0) was related to seedling mortality.</p><h3 data-test=\\\"abstract-sub-heading\\\">Conclusion</h3><p>Adopting a dynamic approach by estimating the times to consume both starch reserves and hydraulic safety margins is highly relevant to improve predictions of tree mortality under the current context of increasing global drought.</p>\",\"PeriodicalId\":7994,\"journal\":{\"name\":\"Annals of Forest Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2024-08-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Annals of Forest Science\",\"FirstCategoryId\":\"97\",\"ListUrlMain\":\"https://doi.org/10.1186/s13595-024-01246-7\",\"RegionNum\":3,\"RegionCategory\":\"农林科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"FORESTRY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Annals of Forest Science","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1186/s13595-024-01246-7","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"FORESTRY","Score":null,"Total":0}
The rates of starch depletion and hydraulic failure both play a role in drought-induced seedling mortality
Key message
The elapsed times to deplete starch concentrations and to reach a null hydraulic safety margin were related to tree seedling mortality under experimental drought. Starch concentration showed an accelerated decline across all species during the early stages of dehydration, while the concentrations of soluble sugars and total nonstructural carbohydrates remained stable. Concomitant carbohydrate depletion and hydraulic failure drive seedling mortality under drought.
Context
Current upsurges of drought events are provoking impacts on tree physiology, resulting in forest mortality. Hydraulic dysfunction and nonstructural carbohydrate (NSC) depletion have been posited as the main mechanisms leading to plant mortality under drought.
Aims
This study explores the dynamics of the two mortality-inducing processes during drought stress using an experimental approach with 12 evergreen tree species.
Methods
Seedlings were subjected to drought until 100% mortality was observed. Midday (ΨMD) and predawn (ΨPD) water potentials, xylem pressure leading to a 50% loss of hydraulic conductivity (Ψ50), along with NSC concentrations in different organs (leaves, stems, and roots) were measured regularly during drought.
Results
Total NSC concentrations and soluble sugar pools did not decline during drought. However, starch pools showed strong reductions early during drought stress as ΨPD decreased, and the time leading to starch depletion emerged as a strong mortality predictor. Ψ50 alone did not provide an accurate estimate of mortality, while the elapsed time to reach a null hydraulic safety margin (ΨMD—Ψ50 = 0) was related to seedling mortality.
Conclusion
Adopting a dynamic approach by estimating the times to consume both starch reserves and hydraulic safety margins is highly relevant to improve predictions of tree mortality under the current context of increasing global drought.
期刊介绍:
Annals of Forest Science is an official publication of the French National Institute for Agriculture, Food and Environment (INRAE)
-Up-to-date coverage of current developments and trends in forest research and forestry
Topics include ecology and ecophysiology, genetics and improvement, tree physiology, wood quality, and silviculture
-Formerly known as Annales des Sciences Forestières
-Biology of trees and associated organisms (symbionts, pathogens, pests)
-Forest dynamics and ecosystem processes under environmental or management drivers (ecology, genetics)
-Risks and disturbances affecting forest ecosystems (biology, ecology, economics)
-Forestry wood chain (tree breeding, forest management and productivity, ecosystem services, silviculture and plantation management)
-Wood sciences (relationships between wood structure and tree functions, and between forest management or environment and wood properties)