Abstract
Plant nucleotide-binding leucine-rich repeat immune receptors (NLRs) directly or indirectly recognize pathogen-secreted effector molecules to initiate plant defense. Recognition of multiple pathogens by a single NLR is rare and usually occurs via monitoring for changes to host proteins; few characterized NLRs have been shown to recognize multiple effectors. The barley NLR Mla has undergone functional diversification and Mla alleles recognize host-adapted isolates of barley powdery mildew (Blumeria graminis f. sp. hordei; Bgh). Here, we show that Mla3 also confers resistance to rice blast (Magnaporthe oryzae) in a dosage dependent manner. Using a forward genetic screen, we discovered that the recognized effector from M. oryzae is PWL2, a host range determinant factor that prevents M. oryzae from infecting weeping lovegrass (Eragrostis curvula). Mla3 has therefore convergently evolved the capacity to recognize effectors from diverse pathogens.
Competing Interest Statement
The authors have declared no competing interest.
