Transcriptomic analysis of bagging-treated 'Pingguo' pear shows that MYB4-like1, MYB4-like2, MYB1R1 and WDR involved in anthocyanin biosynthesis are up-regulated in fruit peels in response to light

Bagging is a competent method to accelerate the development of fruit color. We report here a high throughput analysis of bagged 'Pingguo' pear fruit peels. We identified 3191 different expressed genes (DEGs) in comparisons of four ripening-stage transcriptomes, of which 32 DEGs were identified as anthocyanin biosynthesis pathway genes. In addition, the expression patterns of the 32 DEGs were validated by qRT-PCR assays, and the results were highly coincide with the RNA-Seq results. In particular, some of the anthocyanin biosynthesis pathway genes, including MYB4-like1, MYB4-like2, MYB1R1 and WDR showed up-regulated expression in the late (day 9) stage after bag removal, concurrent with changes in anthocyanin content. We also identified 1025 new genes in the course of this study. The RNA-Seq analysis provides meanningful information for make outing the mechanisms of anthocyanin biosynthesis in bagging-treated 'Pingguo' pear fruits.