Characterization of AtCHX17, a member of the cation/H+ exchangers, CHX family, from Arabidopsis thaliana suggests a role in K+ homeostasis
Characterization of AtCHX17, a member of the cation/H+ exchangers, CHX family, from Arabidopsis thaliana suggests a role in K+ homeostasis
复制标题
DOI：
10.1111/j.1365-313x.2004.02177.x
复制
发表时间：
2004-09-01
期刊：
影响因子：
7.2
通讯作者：
Casse, F
中科院分区：
文献类型：
--
作者：
Cellier, F;Conéjéro, G;Casse, F
拟南芥基因组包含许多编码H+偶联共转运蛋白的序列。其中包括阳离子：质子逆向转运蛋白-2(CPA2)家族(或CHX家族)，被认为编码Na+，K+/H+逆向转运蛋白。选择CPA2家族成员AtCHX17进行表达研究，并对基因敲除突变体进行表型分析。AtCHX17仅在根中表达。该基因受盐胁迫、钾饥饿、脱落酸(ABA)和外界酸性pH的强烈诱导。利用β-葡萄糖醛酸酶报告基因策略和原位RT-PCR实验，我们发现AtCHX17在成熟根区的表皮和皮质细胞中优先表达。与野生型相比，基因敲除突变体对盐胁迫和钾饥饿的响应在根中积累的K+较少。这些数据支持AtCHX17参与K+的获取和动态平衡的假设。
The Arabidopsis genome contains many sequences annotated as encoding H+-coupled cotransporters. Among those are the members of the cation:proton antiporter-2 (CPA2) family (or CHX family), predicted to encode Na+,K+/H+ antiporters. AtCHX17, a member of the CPA2 family, was selected for expression studies, and phenotypic analysis of knockout mutants was performed. AtCHX17 expression was only detected in roots. The gene was strongly induced by salt stress, potassium starvation, abscisic acid (ABA) and external acidic pH. Using the beta-glucuronidase reporter gene strategy and in situ RT-PCR experiments, we have found that AtCHX17 was expressed preferentially in epidermal and cortical cells of the mature root zones. Knockout mutants accumulated less K+ in roots in response to salt stress and potassium starvation compared with the wild type. These data support the hypothesis that AtCHX17 is involved in K+ acquisition and homeostasis.