Inhibition of RNase to attenuate fungal-manipulated rhizosphere microbiome and diseases

Mining microbial communities specifically disrupted by fungal rnase effectors.Phytopathogens utilize effector proteins to manipulate host immunity and promote niche colonization. Here, we show that the soil-borne pathogen Fusarium graminearum can manipulate the plant-associated rhizosphere microbiome through the virulence effector Fg12, which encodes a fungal-specific ribonuclease (RNase). Fg12 is widely distributed among various fungal pathogens, and its antibacterial function relies on RNase activity. Some Fg12-inhibited bacteria, both individually and in synthetic communities (Syncoms), can alleviate F. graminearum infection in soybean and alfalfa plants. Moreover, we employed structural modeling, molecular docking, and in vitro enzymatic assays to demonstrate that guanosine monophosphate (GMP) functions as an effective chemical inhibitor of Fg12. Notably, GMP efficiently inhibits the antibacterial activity of Fg12 and effectively attenuates fungal diseases in soybean and alfalfa. In conclusion, we demonstrate that a virulence effector of a fungal phytopathogen can interfere with the host microbiome and present GMP as a potential RNase inhibitor for attenuating plant fungal diseases.