Donn G, Tischer E, Smith J A, Goodman H M
J Mol Appl Genet. 1984;2(6):621-35.
We have selected alfalfa suspension cell lines that are 20- to 100-fold more resistant than wild-type cells to the nonselective herbicide L-phosphinothricin, a mixed competitive inhibitor of glutamine synthetase (GS). GS enzyme levels are three- to sevenfold elevated in the variant cell line. Partial amino acid sequences of two cyanogen bromide cleavage peptides have been determined on GS purified from the variant cell line and used to confirm the identity of a 276-base pair GS cDNA clone. Southern blot analysis of wild-type and variant cell DNAs using this cDNA as a probe indicate that resistance to L-phosphinothricin is a consequence of a four- to 11-fold amplification of one GS gene resulting in about an eightfold increase in mRNA levels, and an increased enzyme synthesis sufficient to overcome the toxic effects of the inhibitor.
我们选择了苜蓿悬浮细胞系，其对非选择性除草剂L-草铵膦（谷氨酰胺合成酶（GS）的混合竞争性抑制剂）的抗性比野生型细胞高20至100倍。在变异细胞系中，GS酶水平提高了三至七倍。已确定从变异细胞系纯化的GS上两个溴化氰裂解肽的部分氨基酸序列，并用于确认一个276碱基对的GS cDNA克隆的身份。使用该cDNA作为探针，对野生型和变异细胞DNA进行Southern印迹分析表明，对L-草铵膦的抗性是一个GS基因扩增4至11倍的结果，导致mRNA水平增加约8倍，以及酶合成增加足以克服抑制剂的毒性作用。
