Fig. 4

Carotenoid concentrations and carotenoid biosynthesis unigenes at different stages. a The concentrations of β-carotene, lycopene, and lutein were determined at different stages. The asterisk indicates a significant difference between the YG or W stages and the G stage (P < 0.05; Student’s t-test). b Carotenoid biosynthesis pathway. The bracketed numbers in red following each gene name indicate the number of corresponding unigenes identified in our database. c All differentially expressed genes involved in carotenoid biosynthesis were hierarchically clustered and mapped using the fragments per kilobase of exon per million mapped reads values. Colors indicate the normalized signal intensity as defined in the bar