Improved peach peel color development by fruit bagging. Enhanced expression of anthocyanin biosynthetic and regulatory genes using white non-woven polypropylene as replacement for yellow paper

Abstract

To overcome the poor peach fruit color problem resulting from fruit bagging with a widely applied yellow paper (YE-P), non-woven polypropylene bags of different colors were tested. Fruit bagged with white non-woven polypropylene (WH-N) developed the deepest red color and accumulated the highest amount of anthocyanin in peel. The effect was consistent for both cultivars tested, ‘Hujingmilu’ and ‘Yulu’. Enhanced expression of three anthocyanin biosynthetic genes, chalcone synthase (CHS), dihydroflavonol 4-reductase (DFR), and UDP-glucose:flavonoid 3-O-glucosyltransferase (UFGT), as well as five regulatory genes, three MYBs (MYB 10.1, MYB 10.2, MYB 10.3), bHLH3, and WD40-1, was observed in peel of WH-N bagged fruit, compared to those bagged with YE-P. These data indicated that the WH-N bag is an ideal replacement for YE-P bags for improving peach fruit color development, and the increased accumulation of anthocyanin is a result of enhanced expression of anthocyanin biosynthetic genes as well as regulatory genes.