Na+/H+逆向转运蛋白调节细胞内的离子内平衡,在植物耐盐性起重要的作用.本研究克隆一个大豆Na+/H+逆向转运蛋白的同源基因GmNHX2,编码一条长534氨基酸的多肽并预测有10个可能的跨膜结构域.GmNHX2在大豆的根、茎和叶中表达,但在根中的丰...Na+/H+逆向转运蛋白调节细胞内的离子内平衡,在植物耐盐性起重要的作用.本研究克隆一个大豆Na+/H+逆向转运蛋白的同源基因GmNHX2,编码一条长534氨基酸的多肽并预测有10个可能的跨膜结构域.GmNHX2在大豆的根、茎和叶中表达,但在根中的丰度最高,受NaCl和PEG(polyethylene glycol)处理的诱导表达.GmNHX2与LeNHX2和AtNHX2的序列相似性高于AtNHX1和AtSOS1.尽管系统发育分析将GmNHX2与细胞器(液泡和囊泡)逆向转运蛋白聚成一类,但亚细胞定位的结果表明GmNHX2-EGFP(enhanced green flurescent protein)融合蛋白可能位于植物细胞的质膜或细胞器膜上.与野生型植株相比,异源表达GmNHX2的拟南芥植株在萌发和幼苗期都更加耐高浓度的NaCl.这些结果暗示,GmNHX2是一个Na+/H+逆向转运蛋白同源物,可能在盐胁迫下执行调节离子内平衡的功能.展开更多
Na+/H+ antiporters have been well documented to enhance plant salt tolerance by regulating cellular ion homeostasis. Here, a putative Na+/H+ antiporter gene homolog GmNHX2 from soybean was cloned and predicted to enco...Na+/H+ antiporters have been well documented to enhance plant salt tolerance by regulating cellular ion homeostasis. Here, a putative Na+/H+ antiporter gene homolog GmNHX2 from soybean was cloned and predicted to encode a protein of 534 amino acids with 10 putative transmembrane domains. GmNHX2 was expressed in all soybean plant tissues but enriched in roots and its expression was induced by NaCl and polyethylene glycol (PEG) treatments. GmNHX2 exhibits greater sequence similarity with LeNHX2 and AtNHX6 than that of AtNHX1 and AtSOS1. Although phylogenetic analysis clustered GmNHX2 with organellar (tonoplast and vesicles) antiporters, the GmNHX2-EGFP (enhanced green fluorescent protein) fusion protein was possibly localized in the plasma membrane or organelle membrane of transgenic plant cells. Furthermore, transgenic Arabidopsis plants expressing GmNHX2 were more tolerant to high NaCl concentrations during germination and seedling stages when compared with wild-type plants. These results suggest that GmNHX2 is a membrane Na+/H+ antiporter and may function to regulate ion homeostasis under salt stress.展开更多
文摘Na+/H+逆向转运蛋白调节细胞内的离子内平衡,在植物耐盐性起重要的作用.本研究克隆一个大豆Na+/H+逆向转运蛋白的同源基因GmNHX2,编码一条长534氨基酸的多肽并预测有10个可能的跨膜结构域.GmNHX2在大豆的根、茎和叶中表达,但在根中的丰度最高,受NaCl和PEG(polyethylene glycol)处理的诱导表达.GmNHX2与LeNHX2和AtNHX2的序列相似性高于AtNHX1和AtSOS1.尽管系统发育分析将GmNHX2与细胞器(液泡和囊泡)逆向转运蛋白聚成一类,但亚细胞定位的结果表明GmNHX2-EGFP(enhanced green flurescent protein)融合蛋白可能位于植物细胞的质膜或细胞器膜上.与野生型植株相比,异源表达GmNHX2的拟南芥植株在萌发和幼苗期都更加耐高浓度的NaCl.这些结果暗示,GmNHX2是一个Na+/H+逆向转运蛋白同源物,可能在盐胁迫下执行调节离子内平衡的功能.
基金Supported by the National Natural Science Foundation of China (Grant No. 30490251)National High Technology Research and Development Program of China (Grant Nos. 2006AA10A110, 2006AA100104)Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period (Grant No. 2006BAD13B05)
文摘Na+/H+ antiporters have been well documented to enhance plant salt tolerance by regulating cellular ion homeostasis. Here, a putative Na+/H+ antiporter gene homolog GmNHX2 from soybean was cloned and predicted to encode a protein of 534 amino acids with 10 putative transmembrane domains. GmNHX2 was expressed in all soybean plant tissues but enriched in roots and its expression was induced by NaCl and polyethylene glycol (PEG) treatments. GmNHX2 exhibits greater sequence similarity with LeNHX2 and AtNHX6 than that of AtNHX1 and AtSOS1. Although phylogenetic analysis clustered GmNHX2 with organellar (tonoplast and vesicles) antiporters, the GmNHX2-EGFP (enhanced green fluorescent protein) fusion protein was possibly localized in the plasma membrane or organelle membrane of transgenic plant cells. Furthermore, transgenic Arabidopsis plants expressing GmNHX2 were more tolerant to high NaCl concentrations during germination and seedling stages when compared with wild-type plants. These results suggest that GmNHX2 is a membrane Na+/H+ antiporter and may function to regulate ion homeostasis under salt stress.
