B1 — Capsicum annuum

Summary

T459_16578 (symbol B1, preferred name CA2) on pepper chromosome 6 encodes a beta-carotene 3-hydroxylase (EC 1.14.15.24) with iron-binding and hydrolase activity, belonging to the BETA-OHASE-like family and localizing to the chloroplast membrane. The gene is associated with carotene metabolism, xanthophyll anabolism, carotenoid anabolism, sucrose metabolism, phenylpropanoid anabolism, chlorophyll fluorescence, response to stress, fruit development, ABA signaling, and response to light stimulus. It has been linked to plant fresh weight, nonphotochemical quenching, flower pigmentation, seed germination, and altered carotenoid profiles in seeds and leaves, including increased beta-carotene-derived xanthophylls and higher lutein levels. Studies of related genes in other species connect the family to xanthophyll accumulation, reduced nonphotochemical quenching, chilling tolerance, and antioxidant capacity.