Anacystis mutants with different tolerances to DCMU-type herbicides show differences in architecture and dynamics of the photosynthetic apparatus, depending on site and mode of the amino acid exchanges in the D 1 protein.
Mutants of Anacystis R 2 with different amino acid exchanges in positions 255 and/or 264 in copy I of the psbA gene, leading to different tolerances to DCMU-type herbicides, are compared with the respective wild type concerning pigmentation and incorporation of 35S into the D 1 protein upon growth in the presence of [35S]methionine. All mutants have shade-type appearance compared to the wild type, although to different extents depending on site and mode of the amino acid exchange in the D 1 protein. Except for 3 mutants, there is no correlation between shade-type appearance on one hand and resistance towards a certain inhibitor on the other hand. Not only the molar ratio of phycocyanin (PC) to chlorophyll (Chl) is higher in all mutants compared to the respective wild type, but also the rate of synthesis of the D 1 protein. On the background of different levels of total 35S incorporation within 18 min, D 1 synthesis can be related to shade adaptation. Degradation of the D 1 protein remains to be thoroughly studied in this context. No reproducible differences in whole chain electron transport were observed between mutants and wild type.
Koenig
F
F
Botanisches Institut der J. W. Goethe-Universität, Frankfurt am Main, Bundesrepublik Deutschland.
D000595:Amino Acid Sequence; D002734:Chlorophyll / Q000235:genetics* / Q000378:metabolism; D000458:Cyanobacteria / Q000187:drug effects / Q000235:genetics*; D004237:Diuron / Q000494:pharmacology*; D006540:Herbicides / Q000494:pharmacology; D045342:Light-Harvesting Protein Complexes; D009154:Mutation; D010788:Photosynthesis / Q000187:drug effects*; D045322:Photosynthetic Reaction Center Complex Proteins; D010798:Phycocyanin / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism
D006540:Herbicides; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D010940:Plant Proteins; D010798:Phycocyanin; D002734:Chlorophyll; D004237:Diuron