Klee H J, Muskopf Y M, Gasser C S
Plant Molecular Biology Group, Monsanto Company, Chesterfield 63198.
Mol Gen Genet. 1987 Dec;210(3):437-42. doi: 10.1007/BF00327194.
5-enolpyruvylshikimate-3-phosphate synthase (EPSPs), the target of the herbicide glyphosate, catalyzes an essential step in the shikimate pathway common to aromatic amino acid biosynthesis. We have cloned an EPSP synthase gene from Arabidopsis thaliana by hybridization with a petunia cDNA probe. The Arabidopsis gene is highly homologous to the petunia gene within the mature enzyme but is only 23% homologous in the chloroplast transit peptide portion. The Arabidopsis gene contains seven introns in exactly the same positions as those in the petunia gene. The introns are, however, significantly smaller in the Arabidopsis gene. This reduction accounts for the significantly smaller size of the gene as compared to the petunia gene. We have fused the gene to the cauliflower mosaic virus 35 S promoter and reintroduced the chimeric gene into Arabidopsis. The resultant overproduction of EPSPs leads to glyphosate tolerance in transformed callus and plants.
5-烯醇丙酮酰莽草酸-3-磷酸合酶（EPSPs）是除草剂草甘膦的作用靶点，它催化芳香族氨基酸生物合成所共有的莽草酸途径中的一个关键步骤。我们通过与矮牵牛cDNA探针杂交，从拟南芥中克隆了一个EPSP合酶基因。拟南芥基因在成熟酶区域与矮牵牛基因高度同源，但在叶绿体转运肽部分只有23%的同源性。拟南芥基因含有七个内含子，其位置与矮牵牛基因中的完全相同。然而，拟南芥基因中的内含子明显更小。这种减小导致该基因与矮牵牛基因相比明显更小。我们已将该基因与花椰菜花叶病毒35S启动子融合，并将嵌合基因重新导入拟南芥。EPSPs的过量表达使转化的愈伤组织和植株具有草甘膦耐受性。
