Miao Lihong, Zhou Junchu
Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
Ying Yong Sheng Tai Xue Bao. 2003 Sep;14(9):1517-20.
Sinorhizobium fredii YC4 can form nitrogen-fixing nodules on soybean (Glycine max) and wild soybean (G. soja). It can produce unique lipochitooligosaccharide nod factors (LCOs), in comparison with the other four strains of S. fredii. The constitution of LCOs produced by YC4 contained more hydrophobic substitutions detected by Thin-layer chromatography (TLC) of 14C-labeled nod factors. A spontaneous mutant termed YSC3 amplified in the symbiotic plasmid was isolated from YC4, which can produce more amount of LCOs than its parental strain at 28 degrees C, and showed a difference in the construction of LCOs. Nodulation test indicated that YSC3 only formed ineffective nodules on soybean G. soja.
费氏中华根瘤菌YC4能在大豆（Glycine max）和野生大豆（G. soja）上形成固氮根瘤。与其他四株费氏中华根瘤菌相比，它能产生独特的脂壳寡糖结瘤因子（LCOs）。通过对14C标记的结瘤因子进行薄层色谱（TLC）分析发现，YC4产生的LCOs组成含有更多的疏水取代基。从YC4中分离出一株在共生质粒中扩增的自发突变体YSC3，在28℃时它能比其亲本菌株产生更多的LCOs，并且在LCOs的结构上存在差异。结瘤试验表明，YSC3仅在野生大豆G. soja上形成无效根瘤。
