非生物胁迫下耐辐射异常球菌drB0118基因功能分析

Functional analysis of drB0118 gene in response to abiotic stress in Deinococcus radiodurans

摘要:

【目的】鉴定和确定被预测为编码干燥相关蛋白的耐辐射异常球菌(Deinococcus radiodurans) drB0118基因功能，探讨该基因对盐、渗透和氧化胁迫抗性的作用。【方法】构建drB0118基因缺失突变株(ΔB0118)，通过氯化钠、D-山梨糖醇和过氧化氢等胁迫冲击实验及氧化胁迫条件下qRT-PCR分析，研究drB0118突变对非生物胁迫反应及氧化胁迫相关基因表达的影响。【结果】drB0118突变导致菌株对NaCl和D-sorbitol胁迫的抗性降低；对氧化胁迫(H2O2)敏感；qRT-PCR分析显示，drB0118突变引起氧化胁迫抗性基因pod和oxyR分别下调4倍和10倍。【结论】D. radiodurans中drB0118参与了盐、渗透和氧化等多种非生物胁迫反应。

Abstract:

[Objective] drB0118 gene in Deinococcus radiodurans is predicted to encode a protein associated with the desiccation tolerance. The purpose of this study is to identify and determine the function of drB0118 gene, especially its effects on the bacterial resistance to salt, osmotic and oxidative stresses. [Methods] The drB0118 mutant was constructed and its tolerance to salt, osmotic and oxidative stresses was investigated by the NaCl, D-sorbitol or H2O2 shock experiments. The expression of the genes involved in oxidative stress response was measured by qRT-PCR assay under the oxidative stress. [Results] The mutant ΔB0118 was more sensitive to NaCl, D-sorbitol and H2O2 stresses than the wild type strain. The inactivation of drB0118 resulted in 4-fold or 10-fold decrease in the relative expression of pod and oxyR genes respectively. [Conclusion] The results suggested that drB0118 gene was involved in salt, osmotic and antioxidant stress in D. radiodurans.