Increased levels of glutathione in a catalase-deficient mutant of barley (Hordeum vulgare L.)

Abstract

The total glutathione content of leaves of the catalase deficient mutant barley RPr 79/4 increased 5- to 10-fold to a maximum of 3 μmol g⁻¹ fresh wt. after growth in air. The proportion of reduced glutathione (GSH) fell from 86% to 42% during this period. Similar results were obtained when wild-type barley leaves were treated with aminotriazole, a catalase inhibitor. It is proposed that the excess H₂O₂ synthesised during photorespiration causes the formation of oxidised glutathione (GSSG).