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Updated: Oct 19, 2026

Measuring Rates of Herbicide Metabolism in Dicot Weeds with an Excised Leaf Assay
Published on: September 7, 2015
Herbicide resistance and supersensitivity in photosystem II
1Lehrstuhl Biochemie der Pflanzen, Ruhr-Universität, Bochum, Germany. walter.oettmeier@ruhr-uni-bochum.de
Abstract:
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.
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