Abstract
It is generally considered that the antioxidant GSH scavenges reactive oxygen species generated during chilling stress, resulting in prolonging the life in plants. We, however, show a paradoxical action of GSH, hastening effect on senescence, in Eustoma grandiflorum, a plant that is evergreen without chilling. Application of GSH induced plant senescence even without chilling. Buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, completely prevented the chilling-induced senescence without decreasing the plant growth rate. BSO-mediated inhibition of the chilling-induced senescence was abolished by GSH but not by other thiols. The application of GSH at various concentrations to a plant with chilling increased endogenous GSH and promoted senescence in a dose-dependent manner. These suggest that GSH essentially and specifically regulates plant senescence, resulting in shortening the life span of E. grandiflorum.
