Regulation of chlorophyll and carotenoid metabolism in citrus fruit

Chlorophyll degradation and carotenoid accumulation are essential processes of fruit maturation in many horticultural plants, and play a crucial role in fruit color and quality. The pathways of chlorophyll and carotenoid biosynthesis and degradation are well understood, and key regulatory genes controlling these pathways have been identified in citrus. This article reviewed the recent research on chlorophyll and carotenoid metabolism in citrus fruits, encompassing the metabolic pathways, transcriptional regulation, influencing factors, and the interplay between chlorophyll and carotenoid metabolism, aiming to provide insights into the molecular regulatory mechanisms governing the coloration of citrus fruits.