Drought survival in conifer species is related to the time required to cross the stomatal safety margin
LAMARQUE, Laurent
Biodiversité, Gènes & Communautés [BioGeCo]
Université du Québec à Trois-Rivières [UQTR]
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Biodiversité, Gènes & Communautés [BioGeCo]
Université du Québec à Trois-Rivières [UQTR]
LAMARQUE, Laurent
Biodiversité, Gènes & Communautés [BioGeCo]
Université du Québec à Trois-Rivières [UQTR]
Biodiversité, Gènes & Communautés [BioGeCo]
Université du Québec à Trois-Rivières [UQTR]
COCHARD, Hervé
Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant [PIAF]
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Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant [PIAF]
Language
en
Article de revue
This item was published in
Journal of Experimental Botany. 2023-11-21, vol. 74, n° 21, p. 6847-6859
Oxford University Press (OUP)
English Abstract
The regulation of water loss and the spread of xylem embolism have mostly been considered separately. The development of an integrated approach taking into account the temporal dynamics and relative contributions of these ...Read more >
The regulation of water loss and the spread of xylem embolism have mostly been considered separately. The development of an integrated approach taking into account the temporal dynamics and relative contributions of these mechanisms to plant drought responses is urgently needed. Do conifer species native to mesic and xeric environments display different hydraulic strategies and temporal sequences under drought? A dry-down experiment was performed on seedlings of four conifer species differing in embolism resistance, from drought-sensitive to extremely drought-resistant species. A set of traits related to drought survival was measured, including turgor loss point, stomatal closure, minimum leaf conductance, and xylem embolism resistance. All species reached full stomatal closure before the onset of embolism, with all but the most drought-sensitive species presenting large stomatal safety margins, demonstrating that highly drought-resistant species do not keep their stomata open under drought conditions. Plant dry-down time to death was significantly influenced by the xylem embolism threshold, stomatal safety margin, and minimum leaf conductance, and was best explained by the newly introduced stomatal margin retention index (SMRIΨ50) which reflects the time required to cross the stomatal safety margin. The SMRIΨ50 may become a key tool for the characterization of interspecific drought survival variability in trees.Read less <
English Keywords
Drought tolerance
embolism resistance
residual transpiration
stomatal closure
stomatal safety margin
tree mortality
Origin
Hal imported