Degradation of glutathione S‐conjugates by a carboxypeptidase in the plant vacuole

Publisher Website
Google Scholar
Abstract
For plants, glutathione conjugation is a major pathway to detoxify organic xenobiotic. Glutathione S‐conjugates (SG‐conjugates) are formed in the cytosol, the in vitro transport over the tonoplast has been described and a final storage in the vacuole has been postulated. We show here that alachlor rapidly accumulates as GS‐conjugates in the plant vacuole and that the first step of its degradation, the formation of the respective γ‐glutamylcysteinyl‐S‐conjugate, is catalyzed by a vacuolar carboxypeptidase. These results suggest the glutathione conjugate as a transport form but not a storage form of xenobiotic molecules.