Persistent decay of fresh xylem hydraulic conductivity varies with pressure gradient and marks plant responses to injury
BREITENSTEIN, Daniel
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
FATICHI, Simone
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
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Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
BREITENSTEIN, Daniel
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
FATICHI, Simone
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
OR, Dani
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
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Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] [ETH Zürich]
Langue
en
Article de revue
Ce document a été publié dans
Plant, Cell and Environment. 2021-02, vol. 44, n° 2, p. 371-386
Wiley
Résumé en anglais
Defining plant hydraulic traits is central to the quantification of ecohydrological processes ranging from land-atmosphere interactions, to tree mortality and water-carbon budgets. A key plant trait is the xylem specific ...Lire la suite >
Defining plant hydraulic traits is central to the quantification of ecohydrological processes ranging from land-atmosphere interactions, to tree mortality and water-carbon budgets. A key plant trait is the xylem specific hydraulic conductivity (K-x), that describes the plant's vascular system capacity to transport water. While xylem's vessels and tracheids are dead upon maturity, the xylem is neither inert nor deadwood, various components of the sapwood and surrounding tissue remaining alive and functional. Moreover, the established definition of K-x assumes linear relations between water flux and pressure gradient by tacitly considering the xylem as a "passive conduit". Here, we re-examine this notion of an inert xylem by systematically characterizing xylem flow in several woody plants using K-x measurements under constant and cyclic pressure gradients. Results show a temporal and pressure gradient dependence of K-x. Additionally, microscopic features in "living branches" are irreversibly modified upon drying of the xylem, thus differentiating the macroscopic definition of K-x for living and dead xylem. The findings highlight the picture of the xylem as a complex and delicate conductive system whose hydraulic behaviour transcends a passive gradient-based flow. The study sheds new light on xylem conceptualization, conductivity measurement protocols, in situ long-distance water transport and ecosystem modelling.< Réduire
Mots clés en anglais
:plant hydraulic traits
plant vascular system
sapflow
xylem conductivity measurements
Origine
Importé de halUnités de recherche