A conserved primary salt tolerance mechanism mediated by HKT transporters: a mechanism for sodium exclusion and maintenance of high K⁺/Na⁺ ratio in leaves during salinity stress

FELIX HAUSER, TOMOAKI HORIE

Plant, Cell & Environment, 2010, 33(4): 552-565  DOI: 10.1111/j.1365-3040.2009.02056.x;      追溯原文......本站官方QQ群：62473826

HKT; ion homeostasis; K+ transport; Na+ toxicity; Na+ transport; salt tolerance

Increasing soil salinity is a serious threat to agricultural productions worldwide in the 21st century. Several essential Na⁺ transporters such as AtNHX1 and AtSOS1 function in Na⁺ tolerance under salinity stress in plants. Recently, evidence for a new primary salt tolerance mechanism has been reported, which is mediated by a class of HKT transporters both in dicots such as Arabidopsis and monocot crops such as rice and wheat. Here we present a review on vital physiological functions of HKT transporters including AtHKT1;1 and OsHKT1;5 in preventing shoot Na⁺ over-accumulation by mediating Na⁺ exclusion from xylem vessels in the presence of a large amount of Na⁺ thereby protecting leaves from salinity stress. Findings of the HKT2 transporter sub-family are also updated in this review. Subjects regarding function and regulation of HKT transporters, which need to be elucidated in future research, are discussed.

一個(gè)由HKT轉(zhuǎn)運(yùn)蛋白介導(dǎo)下的保守的耐鹽機(jī)制：水稻葉片在鹽脅迫下，排出鈉鹽，維持高的K⁺/Na⁺比率

土壤鹽漬危害的加重對(duì)21世紀(jì)的全球農(nóng)業(yè)生產(chǎn)構(gòu)成嚴(yán)重威脅。一些重要的Na⁺轉(zhuǎn)運(yùn)蛋白如AtNHX1和AtSOS1對(duì)遭遇鹽漬化的植物起到一定的耐鹽作用。最近，一個(gè)新的重要的耐鹽機(jī)制已有報(bào)道。該機(jī)制是由HKT轉(zhuǎn)運(yùn)蛋白介導(dǎo)實(shí)現(xiàn)的，該機(jī)制在雙子葉擬南芥和單子葉水稻、小麥都有發(fā)現(xiàn)。本文主要介紹擬南芥AtHKT1;1和水稻OsHKT1;5兩個(gè)HKT轉(zhuǎn)運(yùn)蛋白重要的生理功能，即在大量Na⁺脅迫下，兩個(gè)蛋白通過介導(dǎo)木質(zhì)部導(dǎo)管排出Na⁺，阻止Na⁺過量積累，從而保護(hù)葉片免受鹽漬脅迫的過程。此外我們也更新了HKT2亞族的作用。而對(duì)HKT轉(zhuǎn)運(yùn)蛋白的相關(guān)功能和調(diào)控機(jī)制的闡釋有待于進(jìn)一步探討。

►基因列表◄
  鈉離子轉(zhuǎn)運(yùn)蛋白 OsHKT1;5; SKC1;OsHKT8
  高親和性鉀離子轉(zhuǎn)運(yùn)蛋白 OsHKT1;1; OsHKT4