Abstract
Chlorophyll b reductase catalyzes the conversion of chlorophyll b to 7-hydroxymethyl chlorophyll a, which is the first step of chlorophyll degradation pathway. There are two isoforms of chlorophyll b reductase, NYC1 and NOL, in Arabidopsis. We analyzed various nyc1 and nol mutants to understand the physiological functions of chlorophyll b reductase. Chlorophyll a/b ratio increased in nol overexpression mutant in green leaves. nyc1 knockout mutant showed the phenotype keeping green color during senescence due to the inhibition of chlorophyll degradation. On the other hand, nol mutant did not show stay-green phenotype. Based on these observations, we will discuss the functions of chlorophyll b reductase in the developmental stages of seed formation, germination, greening and senescence in Arabidopsis.
