Abstract

Pericarp color is an important economic characteristic ofZanthoxylum bungeanum. Anthocyanins are the main reason for the pericarp’s red appearance inZ. bungeanum. In this study, through the combined analysis of the metabolome and transcriptome,HY5, whose expression is highly correlated to changes in the anthocyanin content, was screened and identified. Under natural ripening conditions, theZ. bungeanumfruit gradually changed in color from green to red, while bagging resulted in the fruit maintaining its green color. After unbagging, the fruit gradually turned red, and theZbHY5expression and anthocyanin content increased. In addition, the leaves changed from green to red after exposure to UV-B radiation, and theZbHY5expression and anthocyanin content increased. The transient overexpression ofZbHY5deepened the redness of theZ. bungeanumleaves and promoted the expression ofZbHY5andZbMYB113as well as anthocyanin accumulation. Bimolecular fluorescence complementation (BIFC) showed that there was an interaction between ZbHY5 and ZbMYB113. These results revealed that under UV-B irradiation, ZbHY5 might regulate the expression levels of the structural genes related to anthocyanin biosynthesis through combination with ZbMYB113, thereby affecting anthocyanin accumulation. This finding provides useful insights for further studies focusing on UV-B-induced anthocyanin accumulation inZ. bungeanum.Keywords:Zanthoxylum bungeanum;anthocyanins;UV-B;ZbHY5;ZbMYB113