P-018 - Conserved effector families in Phytophthora species enable plant to recognize a wide range of pathogens via NLR

Here, we observed that multiple RxLR effector families including 12 reported avirulence effectors of Phytophthora infestans are broadly conserved across the Phytophthora species. We cloned 69 effectors distributed into 8 families from 6 Phytophthora species, and confirmed that 60.87% (42/69) of the tested effectors were similarly recognized by each Solanum NLR (R1, R2, R3a, R8, Rpi-amr1, Rpi-blb1, Rpi-blb2, Rpi-vnt1) according to their defined families. Notably, all the tested Solanum NLRs, except for Rpi-blb2, were able to recognize homologous effectors of multiple Phytophthora species. Furthermore, we also confirmed that expression of R1, R8, and Rpi-amr1 conferred broad-spectrum resistance against multiple Phytophthora species in Nicotiana benthamiana.

Combined results suggest that conserved effector families of Phytophthora species allow Solanaceae plants to recognize wide-range of pathogens by using NLRs that originally reported to recognize P. infestans. Thus, NLR-mediated recognition would contribute to NHR against evolutionarily related pathogens that possess similar repertoires of effectors. Moreover, considering that resistance genes against most of Phytophthora species, except for P. infestans, have never been identified, homology-based approach would provide an alternative strategy to identify functional NLRs against multiple pathogens threatening crop production.