Figure 7.

Proposed model for the enhanced resistance seen in Δnrd1 mutants. Fls3 appears to regulate two opposing host responses: (1) To resist Pst infection, Fls3 and other PRRs induce ROS, MAPK, and other defense responses which inhibit Pst growth. (2) Fls3 also induces Nrd1 gene expression, and increases Nrd1 protein abundance, which suppresses a subset of defense genes and also induces a subset of susceptibility genes further promoting susceptibility to Pst infection. When Nrd1 is mutated, the subset of defense genes, including Agp1, are no longer suppressed (or are induced) and S genes are not expressed leading to enhanced resistance to Pst.