A Herbicide Resistant Euglena Mutant Carrying a Ser to Thr Substitution at Position 265 in the D1 Protein of Photosystem II

Abstract

A herbicide resistant Euglena mutant (MSI) has been obtained by adapting wild type cells to increasing concentrations of DCMU (3-(3′,4′-dichlorophenyl)-1,1-dimethylurea). Lower resistance levels towards DCMU and metribuzin were observed in MSI when compared with Euglena or Chlamydomonas mutants with Ser 264 to Ala substitutions. RNA-sequence analysis identified a Ser to Thr change at position 265 (equivalent to position 264 in other organisms), thus making it possible to compare the influence of amino acids Ser, Ala and Thr at identical positions on the inhibitory effect of structurally different herbicides in the same species.