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Storage of carbon reserves in spruce trees is prioritized over growth in the face of carbon limitation.
Huang, Jianbei; Hammerbacher, Almuth; Gershenzon, Jonathan; van Dam, Nicole M; Sala, Anna; McDowell, Nate G; Chowdhury, Somak; Gleixner, Gerd; Trumbore, Susan; Hartmann, Henrik.
Afiliação
  • Huang J; Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, 07745 Jena, Germany; hjianbei@bgc-jena.mpg.de hammerbacher@fabi.up.ac.za.
  • Hammerbacher A; Forestry and Agricultural Biotechnology Institute, Department of Zoology and Entomology, University of Pretoria, 0028 Pretoria, South Africa; hjianbei@bgc-jena.mpg.de hammerbacher@fabi.up.ac.za.
  • Gershenzon J; Department of Biochemistry, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany.
  • van Dam NM; Molecular Interaction Ecology, German Centre for Integrative Biodiversity Research, 04103 Leipzig, Germany.
  • Sala A; Institute of Biodiversity, Friedrich Schiller University, 07743 Jena, Germany.
  • McDowell NG; Division of Biological Sciences, University of Montana, Missoula, MT 59812.
  • Chowdhury S; Atmospheric Sciences & Global Change, Pacific Northwest National Laboratory, Richland, WA 99354.
  • Gleixner G; Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, 07745 Jena, Germany.
  • Trumbore S; Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, 07745 Jena, Germany.
  • Hartmann H; Department of Biogeochemical Processes, Max Planck Institute for Biogeochemistry, 07745 Jena, Germany.
Proc Natl Acad Sci U S A ; 118(33)2021 08 17.
Article em En | MEDLINE | ID: mdl-34389667
ABSTRACT
Climate change is expected to pose a global threat to forest health by intensifying extreme events like drought and insect attacks. Carbon allocation is a fundamental process that determines the adaptive responses of long-lived late-maturing organisms like trees to such stresses. However, our mechanistic understanding of how trees coordinate and set allocation priorities among different sinks (e.g., growth and storage) under severe source limitation remains limited. Using flux measurements, isotopic tracing, targeted metabolomics, and transcriptomics, we investigated how limitation of source supply influences sink activity, particularly growth and carbon storage, and their relative regulation in Norway spruce (Picea abies) clones. During photosynthetic deprivation, absolute rates of respiration, growth, and allocation to storage all decline. When trees approach neutral carbon balance, i.e., daytime net carbon gain equals nighttime carbon loss, genes encoding major enzymes of metabolic pathways remain relatively unaffected. However, under negative carbon balance, photosynthesis and growth are down-regulated while sucrose and starch biosynthesis pathways are up-regulated, indicating that trees prioritize carbon allocation to storage over growth. Moreover, trees under negative carbon balance actively increase the turnover rate of starch, lipids, and amino acids, most likely to support respiration and mitigate stress. Our study provides molecular evidence that trees faced with severe photosynthetic limitation strategically regulate storage allocation and consumption at the expense of growth. Understanding such allocation strategies is crucial for predicting how trees may respond to extreme events involving steep declines in photosynthesis, like severe drought, or defoliation by heat waves, late frost, or insect attack.
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Texto completo: 1 Base de dados: MEDLINE Assunto principal: Estresse Fisiológico / Carbono / Picea Idioma: En Ano de publicação: 2021 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Estresse Fisiológico / Carbono / Picea Idioma: En Ano de publicação: 2021 Tipo de documento: Article