Pathogen small RNAs as host immune suppressors
Different pathogens release a diverse range of biomolecules during host colonization to support infection. Recently, we have identified small RNAs produced by the fungal plant pathogen Botrytis cinerea that enter the host cell during infection and suppress host plant immunity. Herein, Botrytis small RNAs mimic the plant microRNAs and hijack the host RNA interference (RNAi) pathway to silence host immunity genes. This discovery provided the first evidence of a fungal pathogen using mobile small RNAs to suppress host plants immunity as a virulence strategy that we name cross-kingdom RNAi. We are currently investigating how widespread small RNA-based virulence strategies and cross-kingdom RNAi are among different microbial host-pathogen systems. Moreover, we are trying to understand how small RNA molecules are transported from pathogen into the host cell during the infection process.