水稻中Na⁺/H⁺ 交换器基因的分子克隆与表达

Molecular cloning and expression of the Na+/H+ exchanger gene in Oryza sativa.

作者信息

Fukuda A, Nakamura A, Tanaka Y

机构信息

Department of Plant Physiology, National Institute of Agrobiological Resources, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.

出版信息

Biochim Biophys Acta. 1999 Jul 7;1446(1-2):149-55. doi: 10.1016/s0167-4781(99)00065-2.

DOI:10.1016/s0167-4781(99)00065-2

PMID:10395929

Abstract

Na+/H+ exchanger catalyzes the countertransport of Na+ and H+ across membranes. We isolated a rice cDNA clone the deduced amino acid sequence of which had homology with a putative Na+/H+ exchanger in Saccharomyces cerevisiae, NHX1. The sequence contains 2330 bp with an open reading frame of 1608 bp. The deduced amino acid sequence is similar to that of NHX1 and NHE isoforms in mammals, and shares high similarity with the sequences within predicted transmembrane segments and an amiloride-binding domain. The expression of the gene was increased by salt stress. These results suggest that the product of the novel gene, OsNHX1, functions as a Na+/H+ exchanger, and plays important roles in salt tolerance of rice.

摘要

钠氢交换体催化钠离子和氢离子跨膜反向运输。我们分离出一个水稻cDNA克隆，其推导的氨基酸序列与酿酒酵母中假定的钠氢交换体NHX1具有同源性。该序列包含2330个碱基对，开放阅读框为1608个碱基对。推导的氨基酸序列与哺乳动物中的NHX1和NHE亚型相似，并且与预测的跨膜区段和氨氯地平结合域内的序列具有高度相似性。该基因的表达受盐胁迫诱导增加。这些结果表明，新基因OsNHX1的产物作为一种钠氢交换体发挥作用，并在水稻耐盐性中起重要作用。