Herbicide detoxification by glutathioneS-transferases as implicated from X-ray structures

Abstract

Herbicide selectivity is a major factor in agricultural weed control and results from the differential detoxification ability of plant species. The special agronomic value of plant GSTs originates mainly from their metabolic herbicide detoxification properties that enhance the herbicide tolerance of crops. Glutathione S‐transferases (GSTs) are a ubiquitous family of multifunctional enzymes involved in the metabolization of a broad variety of xenobiotics (eg herbicides in plants) and reactive endogenous compounds through covalent linkage to glutathione. The metabolization of FOE 5043 results in a GSH conjugate that is subsequently degraded by release of the thiadiazole moiety. The comparison of crystal structures of different GST classes, including plant GSTs, provides a model system to understand active‐site interactions on a molecular level. Additional protein structures of three plant GSTs (Arabidopsis thaliana GST, GST I and III from Zea mays var. mutin) in complex with several ligands (S‐hexylglutathione, S‐lactoylglutathione, and FOE 5043) may be tools to supply detailed knowledge for the rational design of new herbicides and GSTs for selectivity optimization in crops. © 1999 Society of Chemical Industry

Effects of tribenuron-methyl treatment on glutathione S-transferase (GST) activities in some wheat and barley varieties

“…When the data is expressed on the basis of μg GSH g -1 fresh weight, the GSH levels were highest in the shoots and lowest in the roots. In the literaure, the increase in enzyme activity was also reported for different plants with various herbicide induction [36,37]. Even the reason of that mechanism is still not very well known, by considering Figs.…”