Host: The Japanese Society of Plant Physiologists
Pages 030
A single amino-acid change (S653N) in the acetolactate synthase (ALS) protein of Arabidopsis confers resistance to the herbicide imazapyr. We have constructed a binary vector, which has a deleted, non-functional fragment from ALS gene, carrying the mutant site specifying herbicide imazapyr resistance. After in planta Agrobacterium-mediated transformation of Arabidopsis, we have selected imazapyr resistant plants. Four imazapyr resistant plants were obtained from 780,000 seeds. S653N mutation was found in two of these imazapyr resistant plants. This result showed that GT by homologous recombination had occurred between the endogenous ALS gene and the engineered ALS gene fragment. From extended analysis, one of the targeting events was concluded as true gene targeting (TGT) effable by double cross over model and another one was concluded as ectopic gene targeting (EGT) arising by modification of vector DNA by chromosomal template and its random integration into Arabidopsis genome.
