Carotenoids are precursors of many bioactive signals in plant, as well as other organisms. Carotenoid-derived plant hormones, strigolactones (SLs) and abscisic acid, are important signal molecules in regulating plant growth and development. Recently, our group identified zaxinone as a novel carotenoid derived bioactive metabolite that is required for normal rice development and which acts by negatively regulating SL biosynthesis. Rice Zaxinone Synthase (ZAS), a member of an overlooked plant Carotenoid Cleavage Dioxygenase (CCD) subfamily, is required for zaxinone production both in vitro and in planta. The rice genome encodes three ZAS homologs, ZAS2, ZAS3 and ZAS4, whose biological and enzymatic functions are unknown.

plant molecular biology reverse genetics CRISPR/Cas apocarotenoids zaxionone