Fig. 1: Red-fleshed apple calli on medium supplemented with different NAA concentrations (5, 10, 20, and 40 μmol/L).
From: Auxin regulates anthocyanin biosynthesis through the Aux/IAA–ARF signaling pathway in apple

a Phenotypes of calli treated with different NAA concentrations, as well as the extraction of anthocyanin. b Relative anthocyanin content at 18 days. The relative anthocyanin content was calculated as follows: absorbance (530 nm)/fresh weight (g). c Relative expression levels of anthocyanin biosynthesis-related genes in response to different NAA treatments at 18 days