Background: Raffinose synthase (RFS) plays a crucial role in plant growth and development, as well as in responses to biotic and abiotic stresses. However, its functions in Brassica napus remain poorly understood. Methods: To investigate the characteristics of the RFS gene family in B. napus (rapeseed), five Arabidopsis thaliana RFS gene sequences were used as references to identify thirteen RFS genes in B. napus, four in Brassica rapa, and six in Brassica oleracea. A comprehensive analysis was conducted, including molecular characteristics, phylogenetic relationships, conserved protein motifs, gene structures, and chromosomal localization. Results: BnaC02G0100500ZS was selected as a candidate gene due to its unique expression profile. Sequence alignment identified it as BnaRFS6, and subcellular localization revealed that its encoded protein is localized in the mitochondria. Overexpression of BnaRFS6 in rapeseed significantly affected the soluble sugar and starch content in the stalks, resulting in increased levels of fructose, glucose, and raffinose, and a decreased starch content. Conclusions: These findings highlight the role of BnaRFS6 in enhancing sugar metabolism in B. napus, particularly in relation to fructose, glucose, and raffinose accumulation. Understanding its potential function provides a foundation for improving the sugar content and taste of rapeseed stalks through genetic engineering in the future.
Zhou et al. (Fri,) studied this question.