Figure 5.

Incorporation of host targets in NLRs leads to the evolution of NLR with integrated domains. NLRs (orange) can sense changes in host proteins (gray) that are targeted by pathogen effector molecules (purple) and initiate defense signaling. Over time, some of these host proteins can be found integrated into the NLR core structure (blue), acting as the effector recognition domains for the NLR. Binding of an effector to the integrated domain of an NLR leads to initiation of defense responses.