HERBICIDES IN PHOTOSYNTHESIS RESEARCH

Photosynthesis and herbicide research have a long common history. Soon after the introduction of a new group of highly effective herbicides in 1956, the substituted aryl ureas, their mode of action was recognized to be the inhibition of light‐driven electron flow and photosynthetic oxygen evolution. Many subsequent highly successful commercial herbicides, including those from other chemical classes, act by this mechanism. The study of their interaction with the photosynthetic system at the molecular level is a prime example of how rapidly advances in unraveling the mechanism of photosynthesis can be translated into practical uses. At the same time the herbicides continued to be valuable and efficient tools in photosynthesis research. In the past herbicides were instrumental in establishing many principal features of the biochemistry and biophysics of photosynthesis, in particular the role of plastoquinone, which is displaced from its binding pocket in one of the protein subunits of the photosystem II. Their further use in elucidating the molecular biology of photosynthesis is illustrated by the recent importance of herbicide‐tolerant mutants for determining structural aspects of photosystem II. We will review the past and present state of the interaction of herbicide and photosynthesis research and will provide a model for the orientation of herbicides within the three dimensional structure of their target, the D1 protein of photosystem II. Copyright © 1991 by VCH Verlagsgesellschaft mbH, Germany