Transcriptome analysis of canola for clubroot resistance
Pyramiding resistance genes may enhance canola defense against clubroot (Plasmodiophora brassicae), and understanding the mechanisms of multigenic resistance can help optimize the deployment of different R genes. We compared the transcriptomes of three canola (Brassica napus L.) DH inbred lines or hybrid, carrying a single R gene on chromosome A03 or A08, or both genes, following the inoculation using pathotype X of P. brassicae, a novel variant found in western Canada recently. The results showed that the resistance is likely conferred by one of the R genes, activating both PTI and ETI signaling pathways during plant defense responses. Additionally, stacking of two R genes showed higher levels of transcript for many of the genes involved in defense responses over those activated by a single R gene. This highlights the benefit of R-gene stacking.