SpAHA1 and SpSOS1 Coordinate in Transgenic Yeast to Improve Salt Tolerance.
In plant cells, the plasma membrane Na+/H+ antiporter SOS1 (salt overly sensitive 1) mediates Na+ extrusion using the proton gradient generated by plasma membrane H+-ATPases, and these two proteins are key plant halotolerance factors. In the present study, two genes from Sesuvium portulacastrum, encoding plasma membrane Na+/H+ antiporter (SpSOS1) and H+-ATPase (SpAHA1), were cloned. Localization of each protein was studied in tobacco cells, and their functions were analyzed in yeast cells. Both SpSOS1 and SpAHA1 are plasma membrane-bound proteins. Real-time polymerase chain reaction (PCR) analyses showed that SpSOS1 and SpAHA1 were induced by salinity, and their expression patterns in roots under salinity were similar. Compared with untransformed yeast cells, SpSOS1 increased the salt tolerance of transgenic yeast by decreasing the Na+ content. The Na+/H+ exchange activity at plasma membrane vesicles was higher in SpSOS1-transgenic yeast than in the untransformed strain. No change was observed in the salt tolerance of yeast cells expressing SpAHA1 alone; however, in yeast transformed with both SpSOS1 and SpAHA1, SpAHA1 generated an increased proton gradient that stimulated the Na+/H+ exchange activity of SpSOS1. In this scenario, more Na+ ions were transported out of cells, and the yeast cells co-expressing SpSOS1 and SpAHA1 grew better than the cells transformed with only SpSOS1 or SpAHA1. These findings demonstrate that the plasma membrane Na+/H+ antiporter SpSOS1 and H+-ATPase SpAHA1 can function in coordination. These results provide a reference for developing more salt-tolerant crops via co-transformation with the plasma membrane Na+/H+ antiporter and H+-ATPase.
Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China; College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China; Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources/College of Agriculture, Hainan University, Haikou, China.
Yang
Y
Zhou
Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources/College of Agriculture, Hainan University, Haikou, China.
Xiaochang
X
Yin
Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
Ruijun
R
Duan
Department of Biochemistry, Taishan Medical University, Tai'an, China.
Gangping
G
Hao
Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China; College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, China.
Jianchun
J
Guo
Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources/College of Agriculture, Hainan University, Haikou, China.
Xingyu
X
Jiang
D035722:Aizoaceae / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D055049:Salt Tolerance / Q000235:genetics*; D012965:Sodium Chloride / Q000494:pharmacology; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics* / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D019076:Transgenes
D010940:Plant Proteins; D017923:Sodium-Hydrogen Exchangers; D012965:Sodium Chloride; D006180:Proton-Translocating ATPases