Insights into the susceptibility of rice to a floral disease

Li, G.-B.; Fan, J.; Liu, J.; Wu, J.-L.; Hu, X.-H.; He, J.-X.; Shen, S.; Wang, H.; Zhu, Y.; He, F.; Gao, H.; Gishkori, Z. G. N.; Zhao, J.-H.; Li, Y.; Huang, F.; Huang, Y.-Y.; Zhao, Z.-X.; Zhang, J.-W.; Zhou, S.-X.; Pu, M.; Chen, X.; Wang, J.; Li, W.; Wu, X.-J.; Ning, Y.; Sun, W.; Wang, W.-M.

doi:10.1101/2021.03.03.433744

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bioRxiv · 10.1101/2021.03.03.433744

Insights into the susceptibility of rice to a floral disease

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Abstract

Crop floral diseases are economically important as they reduce grain yield and quality and even introduce food toxins. Rice false smut has emerged as a serious floral disease producing mycotoxins. However, very little is known on the interaction mechanisms between rice flower and the causal fungus Ustilaginoidea virens. Here we show that a conserved anti-fungal immunity in rice flower is disarmed by U. virens via a secreted protein UvChi1. UvChi1 functioned as an essential virulence factor and directly interacted with the chitin receptor CEBiP and co-receptor CERK1 in rice to disrupt their oligomerizations and subsequent immune responses. Moreover, intraspecific-conserved UvChi1 could target OsCEBiP/OsCERK1 receptor complex in at least 98.5% of 5232 surveyed rice accessions. These results demonstrate that U. virens utilizes a crucial virulence factor to subvert chitin-triggered flower immunity in most rice varieties, providing new insights into the susceptibility of rice to false smut disease. One Sentence SummaryThe fungal pathogen Ustilaginoidea virens disarms chitin-triggered immunity in rice flower via a secreted chitinase.

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Li, G.-B., Fan, J., Liu, J., Wu, J.-L., Hu, X.-H., He, J.-X., Shen, S., Wang, H., Zhu, Y., He, F., Gao, H., Gishkori, Z. G. N., Zhao, J.-H., Li, Y., Huang, F., Huang, Y.-Y., Zhao, Z.-X., Zhang, J.-W., Zhou, S.-X., Pu, M., Chen, X., Wang, J., Li, W., Wu, X.-J., Ning, Y., Sun, W., Wang, W.-M.. 2021-03-04. Insights into the susceptibility of rice to a floral disease. https://doi.org/10.1101/2021.03.03.433744

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