A Preliminary Study on the White Flower Regulation Mechanism of Four White-flowered Brassica napus Varieties

Purpose White flower is an extremely familiar mutant type in Brassica napus L., the study on regulation mechanism of different white flower materials may lay the foundation of the breeding and production in B. napus.

Methods Evolution analysis, clone sequencing and gene expression level analysis on the BnaC3.CCD4 gene in four white flower varieties (M50, M55, M58 and M61) were used to study its bioinformatics and genetics characteristics. Meanwhile, selected genes related to the carotenoid pathway were analyzed to preliminary study the formation mechanism of white flower in the four B. napus varieties.

Results BnaC3.CCD4 had a closest relationship with CCD4 in B. oleracea, both of them had no TE1 transposon insertion and other mutations. The sequences of BnaC3.CCD4 gene in the four varieties were totally consistent. However, they showed differences in the carotenoid biosynthesis and metabolism pathways, particularly, the PSY and LCYB genes in the biosynthesis pathway showed high expression in blooming petals period of M61, which resulted in pale white or yellow petals.

Conclusion The changes of gene expression related to the carotenoid biosynthesis and metabolism pathways lead to white flowers in the four varieties, in which BnaC3.CCD4 and ZEP gene played a role to some extent.