Mutation in phenol‐type herbicide resistance maps within thepsbA gene inSynechocystis6714

Abstract
ASynechocystis6714 mutant resistant to the phenol‐type herbicide ioxynil was isolated and characterized. Sensitivity to DCMU and atrazine was measured in whole cells and isolated thylakoids. The mutant presents the same sensitivity to atrazine as the wild type and a slightly increased sensitivity to DCMU. A point mutation has been found at codon 266 in thepsbAI coding locus (AAC to ACC) resulting in an amino acid change from asparagine to threonine in the D1protein.