Modulation of Brassica napus and Plasmodiophora brassicae transcriptomes under nitrogen constraint.

The aim was to study the influence of N supply on interactions between B. napus and P. brassicae, through a dual-transcriptomics approach. On one hand, the underlying mechanisms of the plant response to pathogen infection under different nitrogen supply were analyzed. On the other hand, the study deciphered how the P. brassicae pathogen functions, related to growth and pathogenesis in the different infection steps of its life cycle, responded to N levels. For this, we followed clubroot disease progression through a time-course (14, 27, and 42 days post-inoculation) in two B. napus genotypes (Yudal and HD-018) under two N supply's conditions (1 mM and 8 mM). To identify molecular regulation in plant and in pathogen potentially involved in the modulation of the disease by nitrogen input levels, we assessed (i) the phenotype of the two host-plant genotypes harboring different responses to N starvation, and (ii) the transcriptomes of plant and pathogen through RNA-seq approach.