Herbicide resistance and supersensitivity in photosystem II.
Resistance to triazine herbicides in higher plants was first observed in 1970. A mutation in the photosystem II reaction center D1 protein at position Ser264 --> Gly is responsible for this resistance. So far, 37 single mutants, 16 double mutants, 5 triple mutants and 5 deletion/insertion mutants in the D1 protein have been obtained by randomly induced and site-directed mutagenesis in cyanobacteria and algae. The influence of these mutations on the binding affinities of different classes of herbicides will be discussed. Because a sufficiently high resolution X-ray structure of photosystem II does not yet exist, the reaction center of purple photosynthetic bacteria, which is homologous to photosystem II, served as a model. In the bacterial reaction center a total of 25 single and 3 double herbicide-resistant mutants have been generated.
Oettmeier
W
W
Lehrstuhl Biochemie der Pflanzen, Ruhr-Universität, Bochum, Germany. walter.oettmeier@ruhr-uni-bochum.de
D004351:Drug Resistance; D006540:Herbicides / Q000494:pharmacology*; D008958:Models, Molecular; D009154:Mutation; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D045332:Photosystem II Protein Complex; D010944:Plants / Q000187:drug effects*; D011487:Protein Conformation
D006540:Herbicides; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex