AUTHOR=Cui Cheng , Zhang Ka , Chai Liang , Zheng Benchuan , Zhang Jinfang , Jiang Jun , Tan Chen , Li Haojie , Chen Daozong , Jiang Liangcai 

TITLE=Unraveling the mechanism of flower color variation in Brassica napus by integrated metabolome and transcriptome analyses

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1419508

DOI=10.3389/fpls.2024.1419508

ISSN=1664-462X

ABSTRACT=<p><italic>Brassica napus</italic> is one of the most important oil crops in the world. Breeding oilseed rape with colorful flowers can greatly enhance the ornamental value of <italic>B. napus</italic> and thus improve the economic benefits of planting. As water-soluble flavonoid secondary metabolites, anthocyanins are very important for the synthesis and accumulation of pigments in the petals of plants, giving them a wide range of bright colors. Despite the documentation of over 60 distinct flower shades in <italic>B. napus</italic>, the intricacies underlying flower color variation remain elusive. Particularly, the mechanisms driving color development across varying flower color backgrounds necessitate further comprehensive investigation. This research undertook a comprehensive exploration through the integration of transcriptome and metabolome analyses to pinpoint pivotal genes and metabolites underpinning an array of flower colors, including beige, beige-red, yellow, orange-red, deep orange-red, white, light-purple, and purple. First, we used a two-way BLAST search to find 275 genes in the reference genome of <italic>B. napus</italic> Darmor v10 that were involved in making anthocyanins. The subsequent scrutiny of RNA-seq outcomes underscored notable upregulation in the structural genes <italic>F3H</italic> and <italic>UGT</italic>, alongside the <italic>MYB75</italic>, <italic>GL3</italic>, and <italic>TTG1</italic> transcriptional regulators within petals, showing anthocyanin accumulation. By synergizing this data with a weighted gene co-expression network analysis, we identified <italic>CHS</italic>, <italic>F3H</italic>, <italic>MYB75</italic>, <italic>MYB12</italic>, and <italic>MYB111</italic> as the key players driving anthocyanin synthesis in beige-red, orange-red, deep orange-red, light-purple, and purple petals. By integrating transcriptome and weighted gene co-expression network analysis findings with anthocyanin metabolism data, it is hypothesized that the upregulation of <italic>MYB75</italic>, which, in turn, enhances <italic>F3H</italic> expression, plays a pivotal role in the development of pigmented oilseed rape flowers. These findings help to understand the transcriptional regulation of anthocyanin biosynthesis in <italic>B. napus</italic> and provide valuable genetic resources for breeding <italic>B. napus</italic> varieties with novel flower colors.</p>