File(s) under permanent embargo
Coordination between leaf, stem, and root hydraulics and gas exchange in three arid‐zone angiosperms during severe drought and recovery
journal contributionposted on 2023-05-19, 22:06 authored by Creek, D, Blackman, CJ, Timothy BrodribbTimothy Brodribb, Choat, B, Tissue, DT
The ability to resist hydraulic dysfunction in leaves, stems, and roots strongly influences whether plants survive and recover from drought. However, the coordination of hydraulic function among different organs within species and their links to gas exchange during drought and recovery remains understudied. Here, we examine the interaction between gas exchange and hydraulic function in the leaves, stems, and roots of three semiarid evergreen species exposed to a cycle of severe water stress (associated with substantial cavitation) and recovery. In all species, stomatal closure occurred at water potentials well before 50% loss of stem hydraulic conductance, while in two species, leaves and/or roots were more vulnerable than stems. Following soil rewetting, leaf‐level photosynthesis (Anet) returned to prestress levels within 2–4 weeks, whereas stomatal conductance and canopy transpiration were slower to recover. The recovery of Anet was decoupled from the recovery of leaf, stem, and root hydraulics, which remained impaired throughout the recovery period. Our results suggest that in addition to high embolism resistance, early stomatal closure and hydraulic vulnerability segmentation confers drought tolerance in these arid zone species. The lack of substantial embolism refilling within all major organs suggests that vulnerability of the vascular system to drought‐induced dysfunction is a defining trait for predicting postdrought recovery.
Australian Research Council
Publication titlePlant, Cell and Environment
Department/SchoolSchool of Natural Sciences
PublisherBlackwell Publishing Ltd
Place of publication9600 Garsington Rd, Oxford, England, Oxon, Ox4 2Dg
Rights statementCopyright 2018 John Wiley & Sons Ltd.