Characterization of the Pale Yellow Petal/Xanthophyll Esterase gene family in citrus as candidates for carotenoid esterification in fruits

In orange-pigmented citrus fruits, the xanthophyll esters are predominant carotenoids, but their biosynthetic origin is currently unknown. this work, seven PYP/XES (Pale Yellow Petal/ Xanthophyll esterase) genes were identified in Citrus genomes, only PYP1-4 and 6 contained structural domains essential for activity. The expression profiles sweet orange other species such as lemon, mandarin pummelo with marked differences fruit pigmentation content of xanthophylls esters, showed upregulation PYP1,2 during ripening fruits. Moreover, transcript levels PYP1, 2 peel pulp accompanied by accumulation ripening. This work reports first time gene family strongly suggests its involvement esterification tissues influence carotenoid pigmentation.