Validation of the expression of genes related to anthocyanin biosynthesis in chrysanthemums. A, Relative expression levels of 13 functional genes related to anthocyanin biosynthesis and five transcription factors under different treatment conditions by RT-qPCR. The x-axis and y-axis represent the five developmental stages of the capitulum and the relative expression level of each gene, respectively. Red and black squares indicate light and shading treatments, respectively. *represents significance at the 0.05 level. All gene expression levels were normalized against CmPP2A. B, The phenotype of the capitulum during five developmental stages. The upper part depicts the capitulum treated under light condition, while the lower part depicts the capitulum treated under dark conditions. Scale bar = 1cm. C, The relative anthocyanin content of different samples detected by the HPLC method. The x-axis and y-axis represent the five developmental stages of the capitulum and the relative anthocyanin content, respectively. Red and black squires indicate light and shading treatment, respectively. D, The inferred light-induced anthocyanin biosynthesis pathway in chrysanthemums.