盐生植物海马齿中与K^＋离子胁迫有关的基因功能初步鉴定

The Primary Function Identification of a K^+-Tolerance Related Gene from a Halophyte S. portulacastrum L.

盐生植物海马齿常年生长在海边沙地,能忍耐高盐干旱。本研究对从海马齿植物盐胁迫下的差减文库(SSH文库)中分离的3个全长基因SRTG152-Ⅰ、SRTG152-Ⅱ和SRTG152-Ⅲ(GenBank:FJ457924,FJ457925和FJ457926)进行了微生物表达和耐盐分析。3个全长基因分别插入pET-22b(+)表达载体,经过1mmol/L的IPTG在37℃下诱导3h,它们均获得了成功表达。耐盐性功能分析表明,3个基因对Ca2+、Mg2+和Na+离子没有抗性,而在900mmol/L高浓度K+离子的胁迫下与对照相比赋予菌株一定的K+离子抗性。所以,我们初步推测这3个全长基因SRTG152-Ⅰ、SRTG152-Ⅱ和SRTG152-Ⅲ是一类与K+离子的抗性相关的基因。

The Halophyte S. portulacastrum L. living in seaside is a kind of high-salt and drought-tolerant plant. In this report, the expression and the salt-tolerant analysis of the three genes SRTG152- Ⅰ , SRTG152- Ⅱ and SRTG152-Ⅲ（GenBank： FJ457924, FJ457925 and FJ457926） isolated from salt stressed SSH bank have been researched in E. coli by inserting them into a vector pET-22b（＋）. The expressing proteins were obtained aiter inducing 3 h with 1 mmol/L IPTG at 37℃. The analysis of their salt tolerances showed that all the three genes did not resist to Ca^2＋, Mg^2＋ and Na^＋, but showed K^＋ resistance under 900 mmol/L K^＋ stress. Thus it is deduced that the three genes SRTG152- I, SRTG152- Ⅱ and SRTG152- Ⅲ are related to K^＋ salt tolerance.