Abstract:

The aim of this study was to explore the effects of harvest color on the pericarp pigment and the expression
levels of anthocyanin biosynthesis-related genes of two kinds of colored ‘Red Fuji’ apples during controlled atmosphere
(CA) storage. The changes in color values, the contents of anthocyanin and chlorophyll in apple peel and the transcriptional
profiles of anthocyanin biosynthesis-related genes were measured by colorimeter, UV spectrophotometry, and quantitative
real-time polymerase chain reaction (qRT-PCR) during storage, respectively. During storage, the content of anthocyanin
changed whereas the content of anthocyanin declined by 51.36%–69.51% in well-colored apple and by 74.45%–95.30%
in bad-colored apple. The content of chlorophyll in well-colored apple significantly decreased compared to bad-colored
apple. At harvest time, the expression levels of anthocyanin biosynthesis-related genes including chalcone isomerase
(CHI), dihydroflavonol-4-reductase (DFR), anthocyanidin reductase (ANR), and flavanone 3-hydroxylase (F3H) except
leucoanthocyanidin dioxygenase (LDOX) were significantly higher in well-colored apples than in bad-colored apples.
During storage, the expression levels of anthocyanin biosynthesis-related genes were significantly reduced. After storage
for four months, the expression levels of CHI, DFR, ANR, and F3H were significantly higher in bad-colored apples. With
the extension of storage time, the expression levels of anthocyanin biosynthesis-related genes were significantly reduced,
resulting in decreased rate of anthocyanin synthesis. “Skin burning” more likely happened in bad-colored ‘Red Fuji’ apples
than in well-colored ones during CA storage.

Key words: apple, anthocyanin, chlorophyll, gene expression, postharvest