Characterization of a Rapeseed Anthocyanin-More Mutant with Enhanced Resistance to Sclerotinia sclerotiorum

Abstract

Anthocyanins are important natural pigments in plants, and they function not only in antioxidation but also in plant stress responses, pollination, and seed propagation. The anthocyanin-more (am) mutant described in our study is a naturally occurring mutant of Brassica napus cultivar Zhongshuang 11. Compared with the wild type (WT), the mutant produced more anthocyanins at the seedling, bolting, and maturity stages, showing purple color in different parts of the plant. The protein expression profiles of the mutant and WT seedling leaves under natural growth conditions were analyzed using proteomics. A total of 32 proteins that exhibited at least 1.5-fold difference in expression between the WT and mutant plants were successfully identified. The proteins were mainly involved in defense/stress/detoxification and photosynthesis. In particular, the defense/stress/detoxification response and anthocyanin synthesis-related proteins were significantly affected in the am mutant. Moreover, we found the am mutant can enhance the resistance to Sclerotinia sclerotiorum compared with the WT. This enhanced disease resistance may result from the increased anthocyanin content, which is also related to antimicrobial activities and inhibiting fungal growth, and the rapid accumulation of reactive oxygen species that are involved in programmed cell death in plants. These results provide a basis for studying the mutant’s molecular mechanism and increase the information available regarding the growth and development of rapeseed under stress conditions.