豌豆根瘤菌ohrB基因的抗氧化和共生固氮表型

发布时间：2018-03-26 20:36

本文选题：豌豆根瘤菌　切入点：ohrB突变株　出处：《华中农业大学学报》2016年03期

【摘要】：采用基因敲除构建豌豆根瘤菌ohr B基因突变株,研究突变株的抗氧化和共生固氮表型。结果表明:ohr B基因不影响菌株在自生培养条件下的生长能力,但对氢过氧化枯烯(cumene hydroperoxyde,Cu OOH)、过氧化氢(H2O2)、次氯酸钠(Na Cl O)等氧化物敏感,且在Cu OOH胁迫下,相比野生型菌株,突变株的存活率显著下降。荧光定量RT-PCR结果显示,豌豆根瘤菌ohr B基因表达不受H2O2诱导,且ohr B基因的缺失对其他抗氧化基因的表达没有影响。共生实验表明,ohr B基因对根瘤菌共生固氮能力及根际定殖能力没有影响,但在7 d瘤龄的豌豆根瘤类菌体中表达水平显著提高,并对根瘤菌结瘤能力有影响。ohr B基因虽对豌豆根瘤菌的自生生长、共生固氮、根圈定殖没有影响,但在抗氧化及竞争结瘤中发挥重要作用。
[Abstract]:Ohr B gene mutants of pea rhizobia were constructed by gene knockout. The antioxidant and symbiotic nitrogen fixation phenotypes of the mutant were studied. However, it was sensitive to the oxides such as cumene hydroperoxydeoxydeoxydeoxydeoxydeoxydehydroperoxide, hydrogen peroxide, sodium hypochlorite and NaClO, and the survival rate of the mutant was significantly lower than that of wild-type strain under Cu OOH stress. The results of fluorescence quantitative RT-PCR showed that the survival rate of the mutant was significantly lower than that of the wild-type strain. The expression of ohr B gene in Rhizobium pea was not induced by H2O2, and the absence of ohr B gene had no effect on the expression of other antioxidant genes. However, the expression level of pea rhizobia at 7 days of age was significantly increased, and the ability of rhizobia nodulation was affected by .ohr B gene, although it had no effect on the growth, symbiotic nitrogen fixation and root colonization of pea rhizobia. But it plays an important role in anti-oxidation and competitive nodulation.
【作者单位】：中南民族大学生命科学学院;
【基金】：湖北省自然科学基金项目(2014CFB914) 中南民族大学中央高校基本科研业务费专项(CZW15023和CZW14001)
【分类号】：Q939.114

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