B1 — Zea mays

Summary

ZM00001EB073250, designated B1 (ZmB1) on maize chromosome 2, encodes a beta-carotene 3-hydroxylase (EC 1.14.15.24) with iron binding and hydrolase activity, belonging to the fatty acid hydroxylase family. The gene is associated with carotene metabolism, xanthophyll anabolism, carotenoid anabolism, lignin anabolism, NO storage, endosperm development, flower development, pollen-pistil interaction, post-embryonic development, short-term memory, and memory. It is localized to the chloroplast membrane. B1 is associated with altered carotenoid profile in seeds with increased beta-carotene-derived xanthophylls, reduced seed carotenoids with increased beta-carotene levels, dramatic carotenoid composition changes with doubled beta-carotene levels, intermediate seed carotenoid levels with higher lutein, altered leaf carotenoid profile with increased β-carotene and zeinoxanthin, carotenoid hydroxylation, carotenoid biosynthesis, nonphotochemical quenching, and seed germination. It is also associated with lutein content, carotene content, carotenoid content, proline content, and anthesis time. Studies of related genes in other species link the family to grain yield, grain weight, drought tolerance, cold tolerance, and plant height.