athione reductase (GR) catalyzes the reduction of glutathione disulfide (GSSG) to reduced glutathione (GSH) and participates in the ascorbate-glutathione cycle, which scavenges H2O2. Here, we report that chloroplastic/mitochondrial GR2 is an important regulator of leaf senescence. Seed development of the homozygous gr2 knockout mutant was blocked at the globular stage. Therefore, to investigate…