文献类型： 外文期刊

作者： Tang, Xiaoqian ¹ ; Zhang, Huilong ¹ ; Shabala, Sergey ² ; Li, Huanyong ⁴ ; Yang, Xiuyan ¹ ; Zhang, Huaxin ¹ ;

作者机构： 1.Chinese Acad Forestry, Res Ctr Saline & Alkali Land Natl Forestry & Gras, Beijing 10091, Peoples R China

2.Univ Tasmania, Tasmanian Inst Agr, Hobart, Tas 7001, Australia

3.Foshan Univ, Int Res Ctr Environm Membrane Biol, Foshan 528000, Guangdong, Peoples R China

4.Tianjin Acad Agr Sci, Tianjin 300384, Peoples R China

关键词： K+/Na+ homeostasis; Na+ sequestration; salt stress; tissue-specific ions distribution

期刊名称：TREE PHYSIOLOGY （ 影响因子：4.196； 五年影响因子：4.727 ）

ISSN： 0829-318X

年卷期： 2021 年 41 卷 7 期

页码：

收录情况： SCI

摘要： Plant 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 eventuallysequestrated 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.