Hydraulic redistribution: limitations for plants in saline soils

Research output: Contribution to journalArticle

Abstract

Hydraulic redistribution (HR), the movement of water from wet to dry patches in the soil via roots, occurs in different ecosystems and plant species. By extension of the principle that HR is driven by gradients in soil water potential, HR has been proposed to occur for plants in saline soils. Despite the inherent spatial patchiness and salinity gradients in these soils, the lack of direct evidence of HR in response to osmotic gradients prompted us to ask the question: are there physical or physiological constraints to HR for plants in saline environments? We propose that build-up of ions in the root xylem sap and in the leaf apoplast, with the latter resulting in a large predawn disequilibrium of water potential in shoots compared with roots and soil, would both impede HR. We present a conceptual model that illustrates how processes in root systems in heterogeneous salinity with water potential gradients, even if equal to those in non-saline soils, will experience a dampened magnitude of water potential gradients in the soil–plant continuum, minimizing or preventing HR. Finally, we provide an outlook for understanding the relevance of HR for plants in saline environments by addressing key research questions on plant salinity tolerance.

Original languageEnglish
Pages (from-to)2437-2446
Number of pages10
JournalPlant Cell and Environment
Volume40
Issue number10
DOIs
Publication statusPublished - 1 Oct 2017

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saline soils
fluid mechanics
Soil
Salinity
Water
water potential
salinity
Water Movements
Xylem
soil
Ecosystem
soil water potential
apoplast
sap
Ions
xylem
root systems
ions
Research
shoots

Cite this

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title = "Hydraulic redistribution: limitations for plants in saline soils",
abstract = "Hydraulic redistribution (HR), the movement of water from wet to dry patches in the soil via roots, occurs in different ecosystems and plant species. By extension of the principle that HR is driven by gradients in soil water potential, HR has been proposed to occur for plants in saline soils. Despite the inherent spatial patchiness and salinity gradients in these soils, the lack of direct evidence of HR in response to osmotic gradients prompted us to ask the question: are there physical or physiological constraints to HR for plants in saline environments? We propose that build-up of ions in the root xylem sap and in the leaf apoplast, with the latter resulting in a large predawn disequilibrium of water potential in shoots compared with roots and soil, would both impede HR. We present a conceptual model that illustrates how processes in root systems in heterogeneous salinity with water potential gradients, even if equal to those in non-saline soils, will experience a dampened magnitude of water potential gradients in the soil–plant continuum, minimizing or preventing HR. Finally, we provide an outlook for understanding the relevance of HR for plants in saline environments by addressing key research questions on plant salinity tolerance.",
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Hydraulic redistribution : limitations for plants in saline soils. / Bazihizina, Nadia; Veneklaas, Erik J.; Barrett-Lennard, Edward G.; Colmer, Timothy D.

In: Plant Cell and Environment, Vol. 40, No. 10, 01.10.2017, p. 2437-2446.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Hydraulic redistribution

T2 - limitations for plants in saline soils

AU - Bazihizina, Nadia

AU - Veneklaas, Erik J.

AU - Barrett-Lennard, Edward G.

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