Barley MLA3 recognizes the host-specificity determinant PWL2 from rice blast (M. oryzae)

Brabham, H. J.; Gomez De La Cruz, D.; Were, V.; Shimizu, M.; Saitoh, H.; Hernandez-Pinzon, I.; Green, P.; Lorang, J.; Fujisaki, K.; Sato, K.; Molnar, I.; Simkova, H.; Dolezel, J.; Russell, J.; Taylor, J.; Smoker, M.; Gupta, Y. K.; Wolpert, T.; Talbot, N. J.; Terauchi, R.; Moscou, M. J.

doi:10.1101/2022.10.21.512921

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bioRxiv · 10.1101/2022.10.21.512921

Barley MLA3 recognizes the host-specificity determinant PWL2 from rice blast (M. oryzae)

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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.

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Brabham, H. J., Gomez De La Cruz, D., Were, V., Shimizu, M., Saitoh, H., Hernandez-Pinzon, I., Green, P., Lorang, J., Fujisaki, K., Sato, K., Molnar, I., Simkova, H., Dolezel, J., Russell, J., Taylor, J., Smoker, M., Gupta, Y. K., Wolpert, T., Talbot, N. J., Terauchi, R., Moscou, M. J.. 2022-10-22. Barley MLA3 recognizes the host-specificity determinant PWL2 from rice blast (M. oryzae). https://doi.org/10.1101/2022.10.21.512921

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