土壌適応因子としてのダイズ根粒菌種の脱窒システム

在本研究中，共培养实验表明，在低氧条件下，日本芽孢杆菌的竞争力弱于重氮芽孢杆菌。NAPC的HEAM染色和NapA的免疫印迹分析表明，在低氧条件下，在硝酸盐存在的情况下，日本双胞菌的NAP水平低于重氮效率双胞菌，这可能是日本双胞菌处于劣势的原因之一。此外，FixP和FixO蛋白(CBB3型高亲和力细胞色素氧化酶的一部分)产量较低可能与日本血吸虫不能产生足够水平的Nap有关。这些结果支持了我之前的观察，即硝酸盐还原能力可能是驱动缓慢根瘤菌分布的一个重要因素，以响应土壤氧气条件。

In the present research, co-culture experiments showed that B. japonicum is less competitive than B. diazoefficiens under low oxigen contidions. Also the heam staining of NapC and immunoblotting analysis of NapA indicated lower levels of Nap in B. japonicum than in B. diazoefficiens under low-oxygen conditions, in the presence of nitrate, as a possible reason for the disadvantage of B. japonicum. Also, the lower production of FixP and FixO protein (part of cbb3-type high-affinity cytochrome oxidase) may be related to the inability of B. japonicum to produce Nap in sufficient levels. These results support my previous observation that nitrate reduction capacity may be an important factor driving the distribution of bradyrhizobia in response to soil oxygen conditions.