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bioRxiv · 10.1101/2025.07.03.663104

Multipartite coevolution shapes plant apoplastic immunity against rice blast fungus

Takeda, T.·Shimizu, M.·Kodan, A.·Utsushi, H.·Kanzaki, E.·Natsume, S.·Imai, T.·Oikawa, K.·Abe, A.·Terauchi, R.
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Abstract

{beta}-1,3-glucan-binding proteins (GBPs) play crucial roles in cell wall integrity, host- pathogen interactions, and stress responses in fungi, making them essential for fungal survival and virulence. Here, we show that a GBP of the causal agent for blast fungus, Magnaporthe oryzae, is involved in multipartite coevolutionary arms race with rice (Oryza sativa). The rice thaumatin-like pathogenesis-related protein 5 (OsPR5) binds to M. oryzae GBP and sequesters it from the fungal cell wall to confer immunity, but this interaction is counteracted by thaumatin-binding proteins secreted by the fungus to suppress apoplastic immunity. Moreover, a rice receptor kinase located at the cell surface has evolved a thaumatin-like domain to detect the fungal GBP and activate immunity. Our findings reveal that GBPs and thaumatin-domain-containing proteins are engaged in intricate coevolutionary dynamics in the rice apoplast. Given the conservation of thaumatin across plants, we propose a general defense mechanism against fungal pathogens.

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Takeda, T., Shimizu, M., Kodan, A., Utsushi, H., Kanzaki, E., Natsume, S., Imai, T., Oikawa, K., Abe, A., Terauchi, R.. 2025-07-06. Multipartite coevolution shapes plant apoplastic immunity against rice blast fungus. https://doi.org/10.1101/2025.07.03.663104

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