DNA methylation balance is involved in anthocyanin accumulation during Vaccinium corymbosum fruit ripening

BACKGROUND: DNA methylation balance is an important regulatory mechanism for mammalian and plant development. The fruit ripening and anthocyanin accumulation of Vaccinium corymbosum are complex developmental processes that involve numerous physiological, biochemical, and structural alterations. OBJECTIVE: This study aimed to investigate the correlation of DNA methylation balance, DNA methylation and demethylation-related gene expression models and anthocyanin accumulation during blueberry fruit ripening. METHODS: The anthocyanin contents during V. corymbosum 'O'Neal' fruit development were evaluated. The V. corymbosum DNA methylation- and anthocyanin accumulation-related genes were isolated, and their relative expression patterns were detected during flower bud enlargement and fruit development. Moreover, the relative expression patterns of anthocyanin biosynthetic genes and the dynamic changes in the DNA methylation of the promoter sequences of key anthocyanin biosynthetic genes were evaluated. RESULTS: The results showed that the DNA methylation level of V. corymbosum fruit was consistent with anthocyanin accumulation during ripening, and the expression levels of anthocyanin biosynthetic and DNA methylation-related genes. CONCLUSIONS: During V. corymbosum fruit ripening, anthocyanin accumulation is regulated partially by DNA methylation balance of VcCHS and VcANS promoters.