Improvement of glyphosate resistance through concurrent mutations in three amino acids of the Pantoea sp. 5-enolpyruvylshikimate-3-phosphate synthase

Abstract

Glyphosate inhibits the target enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in the shikimate pathway. A mutant of EPSPS from Pantoea sp. was identified using site-directed mutagenesis. The mutant showed significantly improved glyphosate resistance. The mutant had mutations in three amino acids: Gly97 to Ala, Thr 98 to Ile, and Pro 102 to Ser. These mutation sites in Escherichia coli have been studied as significant active sites of glyphosate resistance. However, in our research, they were found to jointly contribute to the improvement of glyphosate tolerance. In addition, the level of glyphosate tolerance in transgenic Arabidopsis confirmed the potentiality of the mutant in breeding glyphosate-resistant plants.