SGR — Arabidopsis thaliana

Summary

AT4G22920 (SGR, also known as NYE1) encodes a Staygreen family protein with 7-hydroxymethyl chlorophyll A reductase, pheophytinase, and chlorophyll b reductase activities, among others. In Arabidopsis, SGR is associated with chlorophyll degradation and leaf senescence, and is linked to the downregulation of chlorophyll breakdown, the chlorophyll cycle, polyamine breakdown, and vitamin E anabolism. The protein localizes to plastid thylakoid membranes and chloroplast envelopes. SGR is associated with traits including leaf yellowing tolerance, hybrid incompatibility, photosynthetic ability, seed longevity, yield, and responses to abscisic acid and cytokinin. Studies of related genes in other species link the family to disease resistance, salinity tolerance, and fruit color.