12.30 - 13.30
Beyond the single gene: NLR network mediates immunity to diverse plant pathogens
Plants evolved immune receptors that detect translocated pathogen virulence proteins known as effectors. These receptors, encoded by disease resistance (R-) genes, belong to a family of nucleotide-binding, leucine-rich repeat proteins (NLR), an ancient class of multi-domain receptors also known to confer innate immunity in animals. An emerging concept of NLR function is that “sensor” NLR proteins are paired with “helper” NLRs to mediate immune signaling. However, our fundamental knowledge of sensor/helper NLRs in plants remains limited.
In this talk, I will describe how we discovered a complex NLR immune network in which helper NLRs in the NRC (NLR-required for cell death) family are functionally redundant but display distinct specificities toward different sensor NLRs that confer immunity to plant pathogens as diverse as oomycetes, bacteria, viruses, nematodes, and insects. NRC family and their NLR sensor mates are phylogenetically related clustering into a well-supported superclade. This NRC-superclade has probably emerged over 100 million years ago from an NLR pair that diversified to constitute up to one half of the NLRs of asterids. These findings reveal a complex genetic network of NLRs by linking evolutionary history to immune signaling.
I will also discuss how pathogens have evolved to suppress the NRC network and the complex coevolutionary dynamics that drive these interactions. We propose that this NLR network increases robustness of immune signaling to counteract rapidly evolving plant pathogens.