To determine molecular responses induced by Rl Norway, we quantified by qRT–PCR the expression of symbiotic marker genes involved in infection, such as Nodule INception (NIN), Nodulation Pectate Lyase (NPL), ExoPolysaccharide receptor 3 (EPR3), ERF Required for Nodulation 1 (ERN1), and SYMbiotic REMorin 1 (SYMREM1) at 3, 7, and 14 days post-inoculation (dpi). The gene discussed is ERN1; the disease is infection.