Taking different curd-colored inbred lines P535 (purple curd) and W535 (white curd) as the test materials, their curd tissue samples were taken at the young curd stage to identify differentially expressed genes and pathways through transcriptome sequencing, in order to further analyze the genetic basis of cauliflower bulb color formation. The results showed that there were 291 differentially expressed genes between P535 and W535, of which 102 genes were upregulated in P535, and 189 genes were downregulated. GO enrichment analysis and KEGG enrichment analysis revealed that the differentially expressed genes were mainly concentrated in pathways such as flavonoid biosynthesis, flavonoid biosynthesis, isoflavone synthesis, and anthocyanin synthesis. Homologous analysis of differentially expressed genes found that 13 anthocyanin synthesis-related genes were significantly upregulated in P535, including a MYB transcription factor BoPAP1, which was speculated to further promote the expression of anthocyanin synthesis structural genes due to the upregulation of BoPAP1 expression, population genotype identification confirms the correlation between BoPAP1 variation and curd color. Sequence analysis showed that the variation in the promoter of BoPAP1 was different from which have been published, indicating that a new natural variation in the regulation caused the cauliflower purple curd formation.
Zhang et al. (Wed,) studied this question.