Biosynthesis and regulatory mechanisms of anthocyanins in rapeseed (Brassica napus).

The review highlights that anthocyanin accumulation in Brassica napus is driven by strong up-regulation of key upstream biosynthetic genes and demonstrates that RNA-seq is an effective strategy for identifying candidate regulators underlying purple-leaf pigmentation in rapeseed. Rapeseed is planted worldwide as an oilseed crop and has been developed as a multifunctional plant. Anthocyanins are important secondary metabolites that play diverse roles in plant development, stress tolerance, and human health. They contribute to the color variation and nutritional value of plants. Many color variants with high-anthocyanin content have been reported in rapeseed species. To provide a comprehensive overview of the biosynthesis, accumulation, and molecular regulation mechanisms of anthocyanins in Brassica napus, this review summarizes research advances on the leaf, stem, seed, and flower color variants, focusing on identification of key genes regulating anthocyanins biosynthesis, accumulation, and regulation by MYB-bHLH-WD40 complexes in the plant. The review also explores how environmental cues such as light and temperature modulate anthocyanin accumulation in rapeseed and highlights the progress and challenges in understanding anthocyanin metabolism in rapeseed. Furthermore, we discuss a simplified procedure to isolate the candidate gene controlling the anthocyanins biosynthesis in Brassica napus, offering insights for basic research.