Barley MLA3 recognizes the host-specificity effector Pwl2 from Magnaporthe oryzae

• Published in: The Plant cell Vol. 36; no. 2; pp. 447 - 470
• Main Authors: Brabham, Helen J, Gómez De La Cruz, Diana, Were, Vincent, Shimizu, Motoki, Saitoh, Hiromasa, Hernández-Pinzón, Inmaculada, Green, Phon, Lorang, Jennifer, Fujisaki, Koki, Sato, Kazuhiro, Molnár, István, Šimková, Hana, Doležel, Jaroslav, Russell, James, Taylor, Jodie, Smoker, Matthew, Gupta, Yogesh Kumar, Wolpert, Tom, Talbot, Nicholas J, Terauchi, Ryohei, Moscou, Matthew J
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 30.01.2024
• Subjects: Ascomycota; Eragrostis - metabolism; Hordeum - genetics; Host Specificity; Magnaporthe; Plant Diseases - microbiology; Plant Proteins - genetics; Plant Proteins - metabolism; Plants - metabolism; Virulence - genetics
• ISSN: 1040-4651; 1532-298X; 1532-298X
• DOI: 10.1093/plcell/koad266

Abstract Plant nucleotide-binding leucine-rich repeat (NLRs) immune receptors 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 (Hordeum vulgare) NLR gene Mildew locus a (Mla) has undergone functional diversification, and the proteins encoded by different 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 the rice blast fungus Magnaporthe oryzae in a dosage-dependent manner. Using a forward genetic screen, we discovered that the recognized effector from M. oryzae is Pathogenicity toward Weeping Lovegrass 2 (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.MLA3 confers dosage-dependent resistance to rice blast through recognition of the effector Pwl2, which contributes to host range dynamics.