BRODRIBB, Tim J.; BOWMAN, David J. M. S.; NICHOLS, Scott; DELZON, Sylvain; BURLETT, Régis

doi:10.1111/j.1469-8137.2010.03393.x

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BRODRIBB, Tim J.
School of Plant Science

BOWMAN, David J. M. S.
School of Plant Science

NICHOLS, Scott
School of Plant Science

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Article de revue

Ce document a été publié dans

New Phytologist. 2010, vol. 188, n° 2, p. 533-542

Wiley

Résumé en anglais

Motivated by the urgent need to understand how water stress-induced embolism limits the survival and recovery of plants during drought, the linkage between water-stress tolerance and xylem cavitation resistance was examined in one of the world’s most drought resistant conifer genera, Callitris. Four species were subjected to drought treatments of −5, −8 and −10 MPa for a period of 3–4 wk, after which plants were rewatered. Transpiration, basal growth and leaf water potential were monitored during and after drought. Lethal water potential was correlated with the tension producing a 50% loss of stem hydraulic conductivity. The most resilient species suffered minimal embolism and recovered gas exchange within days of rewatering from −10 MPa, while the most sensitive species suffered major embolism and recovered very slowly. The rate of repair of water transport in the latter case was equal to the rate of basal area growth, indicating xylem reiteration as the primary means of hydraulic repair. The survival of, and recovery from, water stress in Callitris are accurately predicted by the physiology of the stem water-transport system. As the only apparent means of xylem repair after embolism, basal area growth is a critical part of this equation.< Réduire

Mots clés

HYDRAULIC

TRANSPIRATION

Mots clés en anglais

CALLITRIS

CAVITATION

CONIFER

DROUGHT

EMBOLISM

GROWTH

RECOVERY