Plant NBLRR proteins are immune receptors named for their characteristic domains. Their mode of action is currently undetermined. The potato NBLRR protein Rx1 has been shown to possess a DNA binding activity in vitro. This thesis presents evidence that Rx1 binds DNA in response to its cognate elicitor CP106 in fixed N. benthamiana leaf material using a novel FRET-FLIM assay. The Rx1 CC and NBARC domains were both shown to possess this DNA binding activity. A nucleocytoplasmic distribution of Rx1 was shown to be required for DNA binding. Potential regulators of Rx1 DNA binding activity were identified using a yeast 2-hybrid screen against the CC domain of Rx1 and their effects on Rx1 DNA binding and Rx1 mediated immunity characterised. The transcription factor NbGLK1 was identified and characterised as a promoter of Rx1 DNA binding using FRET-FLIM and a promotor of Rx1 mediated extreme resistance to PVX. However, NbGLK1 was not found to affect Rx1 mediated HR. The protein NbMLHP was also identified in the yeast 2-hybrid screen. This protein was not found to impact Rx1 DNA binding in FRET-FLIM assays. It was, however, identified as a suppressor of Rx1 mediated extreme resistance to PVX (but not HR), and Rx1 did inhibit NbMLHP DNA binding.