biostudies-literatureSuarez JVBiotechnology and Biological Sciences Research Councile99894https://www.ebi.ac.uk/biostudies/studies/S-EPMC4061028biostudies-literatureUnknown9(6)The green alga Chlamydomonas reinhardtii provides a tractable genetic model to study herbicide mode of action using forward genetics. The herbicide norflurazon inhibits phytoene desaturase, which is required for carotenoid synthesis. Locating amino acid substitutions in mutant phytoene desaturases conferring norflurazon resistance provides a genetic approach to map the herbicide binding site. We isolated a UV-induced mutant able to grow in very high concentrations of norflurazon (150 µM). The phytoene desaturase gene in the mutant strain contained the first resistance mutation to be localised to the dinucleotide-binding Rossmann-likedomain. A highly conserved phenylalanine amino acid at position 131 of the 564 amino acid precursor protein was changed to a valine in the mutant protein. F131PloS oneA new F131V mutation in Chlamydomonas phytoene desaturase locates a cluster of norflurazon resistance mutations near the FAD-binding site in 3D protein models.PMC406102895/A2/P/00330Suarez JVDay ABanks SThomas PGfalseA new F131V mutation in Chlamydomonas phytoene desaturase locates a cluster of norflurazon resistance mutations near the FAD-binding site in 3D protein models.The green alga Chlamydomonas reinhardtii provides a tractable genetic model to study herbicide mode of action using forward genetics. The herbicide norflurazon inhibits phytoene desaturase, which is required for carotenoid synthesis. Locating amino acid substitutions in mutant phytoene desaturases conferring norflurazon resistance provides a genetic approach to map the herbicide binding site. We isolated a UV-induced mutant able to grow in very high concentrations of norflurazon (150 µM). The phytoene desaturase gene in the mutant strain contained the first resistance mutation to be localised to the dinucleotide-binding Rossmann-likedomain. A highly conserved phenylalanine amino acid at position 131 of the 564 amino acid precursor protein was changed to a valine in the mutant protein. F1312014-01-01T00:00:00Z20142025-04-04T08:43:39.776Z2019-03-26T23:24:55ZS-EPMC40610282493679110.1371/journal.pone.0099894