Expression Profiling and Interaction Effects of Three R-Genes Conferring Resistance to Blackleg Disease in Brassica napus

Brassica napus L. is one of the world’s most important oilseed crops. Blackleg disease is a serious, yield-limiting factor in the cultivation of oilseed rape. Genetic resistance is primarily conferred by major resistance (R) genes. In this study, we analyzed the expression of the blackleg resistance genes Rlm3, Rlm4, and Rlm7 following inoculation with the Leptosphaeria maculans isolate using the RT-qPCR method. Additionally, we demonstrated and assessed their interactions. The results showed that, while Rlm3 was weakly induced, Rlm4 and Rlm7 displayed variable expression post-inoculation. The correlation between phenotypic and genotypic similarity was low. This suggests that transcriptional responses do not fully explain resistance patterns. Furthermore, significant main effects of the analyzed genes, as well as two- and three-way interactions, were indicated. These results support current knowledge of gene-mediated resistance to blackleg in oilseed rape.