Abstract
We have found that vernalization stimulates the synthesis of reduced glutathione (GSH) and synthesized GSH induces the bolting of the rosette plant Eustoma grandiflorum. In this study, we investingated whether GSH specifically induces bolting. The application of GSH increased the bolting frequency of non-vernalized plants, but that of oxidized glutathione had no such effect. Like GSH, the application of cysteine, a precursor of GSH, induced bolting, while neither dithiothreitol (DTT) nor 2-mercaptoethanol induced bolting. The inductive effect of vernalization on bolting was nullified by the addition of buthionine sulfoximine (BSO), an inhibitor of GSH synthesis. When GSH was applied at the same time as BSO, the bolting frequency was restored. However, DTT or cysteine had no restoring effect on bolting in BSO-treated plants. Thus, the effect of BSO could be reversed only by GSH, but not by other thiols. These suggest that vernalization-induced bolting is specifically regulated by GSH.
