耐辐射球菌Rsr增强大肠杆菌抗逆性的研究

RADIORESISTANT BACTERIUM Deinococcus radiodurans Rsr PROTEIN ENHANCES ABIOTIC STRESS TOLERANCE OF Escherichia coli

耐辐射球菌(Deinococcus radiodurans)Rsr蛋白(DR_1262编码)是一种对辐射抗性起重要作用的RNA结合蛋白。本研究将完整的rsr基因连接到带有groESL启动子的pMD-GroE载体上,构建了Rsr表达菌株。以含空载质粒pMD-GroE的大肠杆菌为对照,发现Rsr的表达提高了大肠杆菌的UV辐射抗性,并增强了细胞的高温和盐抗性。实时定量PCR分析显示在盐胁迫条件下Rsr表达菌株海藻糖合成酶基因的表达上调,暗示Rsr提高了大肠杆菌胞内海藻糖的积累,促进了细胞的盐耐受能力。

The Deinococcus radiodurans Rsr protein（encoded by DR_1262）,an RNA-binding protein contributes to radiation resistance.To study the effect of Rsr in Escherichia coli,we compared the abiotic stress response in an E.coli control strain carrying only the pMD-GroE plasmid and a transformant strain expressing Rsr under control of the groESL promoter.The results indicated that D.radiodurans Rsr not only improved the resistance of E.coli to ultraviolet irradiation,but also confered enhanced temperature and salt tolerance in E.coli.Quantitative real-Time PCR analysis showed that the expression of trehalose synthase genes was upregulated under salt stress in the Rsr-expressing strain,suggesting that the accumulation of high levels of the trehalose leads to the improved salt tolerance.