Role of an ATP binding cassette (ABC) transporter MdABCI17 in the anthocyanin accumulation of apple

As a key colorant and antioxidant in human diets, anthocyanin is biosynthesized in cytosols and transported to vacuoles and other sites for storage. Therefore, the tonoplast transporters of anthocyanin play a key role in the anthocyanin storage and accumulation of plants. In this study, an ATP-binding cassette (ABC) transporter MdABCI17, which is located in the tonoplast, was identified. There was a positive correlation between the MdABCI17 expression and the anthocyanin accumulation during apple fruit ripening. Transgenic analysis showed that up-regulation of MdABCI17 expression in apple fruit and calli significantly increased anthocyanin content. Additionally, the expression of multiple anthocyanin biosynthesize genes, such as MdANS, MdCHS, MdCHI, MdDFR, and MdUFGT, was remarkably upregulated in apple fruit and calli with upregulated expression of MdABCI17, further demonstrating the critical role of MdABCI17 in the anthocyanin accumulation of apple. In summary, the expression of MdABCI17 had positive effects on anthocyanin accumulation, which will be useful for improving the quality of apple and other plants.

Automated summary

In this study, a tonoplast ATP-binding cassette transporter, MdABCI17, was found to be involved in the regulation of anthocyanin accumulation during apple fruit ripening. Up-regulation of MdABCI17 expression significantly increased anthocyanin content and promoted the expression of other anthocyanin biosynthesize genes.