Comparative transcriptome analysis reveals distinct responsive biological processes in radish genotypes contrasting for Plasmodiophora brassicae interaction.

• The transcriptome of resistant and susceptible radish inoculated with P. brassicae. was determined. • Stress/defense response and hormone metabolic process are directly involved in the defense response process. • Effector-triggered immunity (ETI) plays key roles in defense response. Plasmodiophora brassicae is a protozoan pathogen that causes clubroot disease, which is one of the most destructive diseases for Brassica crops, including radish. However, little is known about the molecular mechanism of clubroot resistance in radish. In this study, we performed a comparative transcriptome analysis between resistant and susceptible radish inoculated with P. brassicae. More differentially expressed genes (DEGs) were identified at 28 days after inoculation (DAI) compared to 7 DAI in both genotypes. Gene ontology (GO) and KEGG enrichment indicated that stress/defense response, secondary metabolic biosynthesis, hormone metabolic process, and cell periphery are directly involved in the defense response process. Further analysis of the transcriptome revealed that effector-triggered immunity (ETI) plays key roles in the defense response. The plant hormones jasmonic acid (JA), ethylene (ET), and abscisic acid (ABA) related genes are activated in clubroot defense in the resistant line. Auxin (AUX) hormone related genes are activated in the developing galls of susceptible radish. Our study provides a global transcriptional overview for clubroot development for insights into the P. brassicae defense mechanisms in radish. [ABSTRACT FROM AUTHOR]