File(s) under permanent embargo
Tissue tolerance mechanisms conferring salinity tolerance in a halophytic perennial species Nitraria sibirica Pall.
journal contribution
posted on 2023-05-21, 04:15 authored by Tang, X, Zhang, H, Sergey ShabalaSergey Shabala, Li, H, Yang, XPlant salt tolerance relies on a coordinated functioning of different tissues and organs. Salinity tissue tolerance is one of the key traits that confer plant adaptation to saline environment. This trait implies maintenance low cytosolic Na+/K+ ratio in metabolically active cellular compartments. In this study, we used Nitraria sibirica Pall., a perennial woody halophyte species, to understand the mechanistic basis of its salinity tissue tolerance. The results showed that the growth of seedlings was stimulated by 100-200 mM NaCl treatment. The ions distribution analysis showed that the leaves act as an Na+ sink, while the plant roots possess superior K+ retention. The excessive Na+ absorbed from the soil was mainly transported to the shoot and was eventually sequestrated into mesophyll vacuoles in the leaves. As a result, N. sibirica could keep the optimal balance of K+/Na+ at a tissue- and cell-specific level under saline condition. To enable this, N. sibirica increased both vacuolar H+-ATPase and H+-PPase enzymes activities and up-regulated the expressions of NsVHA, NsVP1 and NsNHX1 genes. Vacuolar Na+ sequestration in the leaf mesophyll, mediated by NsVHA, NsVP1 and NsNHX1, reduced the Na+ concentration in cytosol and inhibited further K+ loss. Meanwhile, N. sibirica enhanced the Two Pore K+ expression at the transcriptional level to promote K+ efflux from vacuole into cytoplasm, assisting in maintaining cytosolic K+ homeostasis. It is concluded that the tissue tolerance traits such as vacuolar Na+ sequestration and intracellular K+ homeostasis are critical to confer adaptation of N. sibirica to soil salinity.
History
Publication title
Tree PhysiologyVolume
41Issue
7Pagination
1264-1277ISSN
0829-318XDepartment/School
Tasmanian Institute of Agriculture (TIA)Publisher
Heron PublishingPlace of publication
202, 3994 Shelbourne St, Victoria, Canada, Bc, V8N 3E2Rights statement
Copyright 2020 The Author(s). Published by Oxford University PressRepository Status
- Restricted