Hydraulic redistribution: limitations for plants in saline soils
Nadia Bazihizina1,2,3, Erik J Veneklaas3,4,5, Edward G Barrett-Lennard3,6,7
1Department of Agrifood Production and Environmental Sciences, Università degli Studi di Firenze, Viale delle Idee 30, 50019 Sesto Fiorentino, Florence, Italy.
Plant, Cell & Environment
|July 15, 2017
Summary
Hydraulic redistribution (HR) may be limited in saline soils due to ion buildup in plant tissues. This conceptual model explains how osmotic gradients can prevent water movement, impacting plant salinity tolerance.
Area of Science:
- Plant Physiology
- Soil Science
- Ecology
Background:
- Hydraulic redistribution (HR) is water movement via roots from wet to dry soil patches.
- HR is typically driven by soil water potential gradients.
- HR in saline soils is proposed but lacks direct evidence.
Purpose of the Study:
- To investigate physical and physiological constraints to HR in saline environments.
- To determine if osmotic gradients impede HR in plants.
- To propose a conceptual model for HR in heterogeneous salinity.
Main Methods:
- Conceptual modeling based on water potential gradients.
- Analysis of ion buildup in root xylem sap and leaf apoplast.
- Evaluation of predawn water potential disequilibrium in shoots vs. roots.
Main Results:
- Ion accumulation in plant tissues can impede HR.
- Large predawn water potential disequilibrium between shoots and roots is likely.
- Dampened water potential gradients in the soil-plant continuum minimize or prevent HR.
Conclusions:
- Salinity imposes constraints on hydraulic redistribution in plants.
- Understanding these constraints is crucial for plant salinity tolerance.
- Further research is needed to address key questions on HR in saline environments.
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