The intracellular immune receptor Rx1 regulates the DNA-binding activity of a Golden2-like transcription factor.

Plant nucleotide-binding leucine-rich repeat (NLR) proteins enable the immune system to recognize and respond to pathogen attack. An early consequence of immune activation is transcriptional reprogramming, and some NLRs have been shown to act in the nucleus and interact with transcription factors. The Rx1 NLR protein of potato is further able to bind and distort double-stranded DNA. However, Rx1 host targets that support a role for Rx1 in transcriptional reprogramming at DNA are unknown. Here, we report a functional interaction between Rx1 and Glk1, a Golden2-like transcription factor. Rx1 binds to Glk1 and Glk1 binds to known Golden2-like consensus DNA sequences. Rx1 reduces the binding affinity of Glk1 for DNA Glk1 activates cellular responses to potato virus X, whereas Rx1 associates with Glk1 and prevents its assembly on DNA unless activated by PVX. This study provides new mechanistic insight into how an NLR can coordinate an immune signaling response at DNA following pathogen perceptions.