A novel carotenoid derivative, lutein 3-acetate, accumulates in senescent leaves of rice.

The biosynthetic pathway of lutein, the most abundant carotenoid in leaves, has been extensively studied, while its degradation pathway during senescence is poorly understood. We found that a novel carotenoid derivative, lutein 3-acetate, accumulates in senescent leaves of rice (Oryza sativa L.). The change in contents of lutein and lutein 3-acetate suggests that lutein is converted to lutein 3-acetate during senescence. Analysis of mutants involved in light-harvesting complex II (LHCII) accumulation and degradation suggests that the converting activity is induced during senescence and that only free lutein, not lutein bound to LHCII, is converted into lutein 3-acetate.