Table1_Whole-Genome Identification and Comparative Expression Analysis of Anthocyanin Biosynthetic Genes in Brassica napus.DOCX

Anthocyanins contribute to most colors of plants and play protective roles in response to abiotic stresses. Brassica napus is widely cultivated worldwide as both an oilseed and a vegetable. However, only several high anthocyanin-containing cultivars have been reported, and the mechanisms of anthocyanin accumulation have not been well-elucidated in B. napus. Here, the phenotype, comparative whole-genome identification, and gene expression analysis were performed to investigate the dynamic change of the anthocyanin content and the gene expression patterns of anthocyanin biosynthetic genes (ABGs) in B. napus. A total of 152 ABGs were identified in the B. napus reference genome. To screen out the critical genes involved in anthocyanin biosynthesis and accumulation, the RNA-seq of young leaves of two B. napus lines with purple leaves (PL) or green leaves (GL), and their F1 progeny at 41, 91, and 101 days were performed to identify the differentially expressed genes. The comparative expression analysis of these ABGs indicated that the upregulation of TT8 together with its target genes (such as DFR, ANS, UFGT, and TT19) might promote the anthocyanin accumulation in PL at the early developmental stage (41–91 days). While the downregulation of those ABGs and anthocyanin degradation at the late developmental stage (91–101 days) might result in the decrease in anthocyanin accumulation. Our results would enhance the understanding of the regulatory network of anthocyanin dynamic accumulation in B. napus.

花色素苷（Anthocyanins）是植物绝大多数色彩的来源，并在应对非生物胁迫时发挥保护性功能。甘蓝型油菜（Brassica napus）兼具油料与蔬菜双重用途，在全球范围内被广泛栽培。然而目前仅报道了少数高花色素苷含量的甘蓝型油菜品种，其花色素苷积累的分子机制尚未得到充分阐明。本研究通过表型分析、全基因组比较鉴定与基因表达分析，探究了甘蓝型油菜中花色素苷含量的动态变化以及花色素苷生物合成基因（anthocyanin biosynthetic genes, ABGs）的表达模式。本研究在甘蓝型油菜参考基因组中共鉴定得到152个ABGs。为筛选参与花色素苷生物合成与积累的关键基因，本研究对两个分别具有紫叶（purple leaves, PL）与绿叶（green leaves, GL）表型的甘蓝型油菜品系及其F1后代，在41天、91天和101天三个时间点的幼叶进行了RNA-seq测序，以鉴定差异表达基因。对这些ABGs的比较表达分析显示，在发育早期（41~91天），TT8与其靶基因（如DFR、ANS、UFGT及TT19）的上调表达可能促进紫叶品系的花色素苷积累；而在发育后期（91~101天），这些ABGs的下调表达与花色素苷降解可能导致花色素苷积累量下降。本研究结果有助于加深对甘蓝型油菜花色素苷动态积累调控网络的理解。