The in vitro growth of Bradyrhizobium diazoefficiens USDA 110 strain is inhibited by glyphosate. The herbicide affects 5-enolpyruvylshikimic acid-3-phosphate synthase, a key enzyme for aromatic aminoacid synthesis. In this study, site-directed mutagenesis was used to change only two nucleotides of the coding region of phosphoenolpyruvate binding site. This change improved the in vitro growth of B. diazoefficiens USDA 110 in the presence of glyphosate, without affecting its normal growth in the absence of the herbicide. Plant co-inoculation experiments demonstrated a better competitiveness of the glyphosate-resistant strain for soybean nodulation in the presence of glyphosate.

中文翻译：

---

在草甘膦存在的情况下，重氮慢生根瘤菌 USDA 110 aroA 的定点诱变提高了大豆结瘤的细菌生长和竞争力

草甘膦抑制重氮慢生根瘤菌USDA 110 菌株的体外生长。除草剂影响 5-烯醇丙酮酸莽草酸-3-磷酸合酶，这是芳香族氨基酸合成的关键酶。在这项研究中，定点诱变仅用于改变磷酸烯醇丙酮酸结合位点编码区的两个核苷酸。这种变化改善了在草甘膦存在下重氮芽孢杆菌USDA 110的体外生长，而在没有除草剂的情况下不影响其正常生长。植物共接种实验表明，在草甘膦存在的情况下，抗草甘膦菌株对大豆结瘤具有更好的竞争力。