Fig. 7
![Fig. 7](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12870-021-03121-3/MediaObjects/12870_2021_3121_Fig7_HTML.png)
Biosynthetic pathways of anthocyanins in apple. A The key genes of the anthocyanin biosynthesis pathway. B qRT-PCR results showing the expression levels of 8 anthocyanin-related genes under the dark (CK), visible light and UV-B radiation treatments in the peel. PAL, phenylalanine ammonia-lyase, XM008357397; CHS, chalcone synthase, XM029091251; CHI, chalcone isomerase, XM008394013; F3H, naringenin 3-dioxygenase, AB074486; DFR, dihydroflavonol 4-reductase, AY227728; ANS, anthocyanidin synthase, AB074487; UFGT, UDP glucose-flavonoid 3–0-glucosyltransferase, MD01G1234400