Different pathogens release a diverse range of biomolecules during host colonization to support infection, such as host cell wall degrading enzymes, toxins, and protein effectors that manipulate host physiology and immunity. We have identified small RNAs synthesized by the fungal pathogen Botrytis cinerea that enter host cells and suppress host immunity. Our recent work provided the first report of a fungal pathogen, Botrytis cinerea that delivers mobile small RNAs into host plants for immune suppression. Herein, Botrytis small RNAs mimic host plant microRNAs and hijack the host RNA interference (RNAi) pathway to silence host immunity genes (1). We investigate whether other pathogens have also evolved small RNA-based virulence strategies. Moreover, is largely missing (2-4). We employ genomics, transcriptomics, bioinformatics, molecular genetics and biochemical approaches to gain fundamental knowledge of the underlying mechanisms of cross-kingdom RNAi. Understanding the molecular mechanisms and factors determining cross-kingdom RNAi bears enormous potential in its application into RNA-based crop biotechnology.
1. A. Weiberg et al., Fungal small RNAs suppress plant immunity by hijacking host RNA interference pathways. Science 342, 118-123 (2013).
2. M. Knip, M. E. Constantin, H. Thordal-Christensen, Trans-kingdom cross-talk: small RNAs on the move. PLoS Genet 10, e1004602 (2014).
3. A. Weiberg, M. Wang, M. Bellinger, H. Jin, Small RNAs: a new paradigm in plant-microbe interactions. Annu Rev Phytopathol 52, 495-516 (2014).
4. A. Weiberg, H. Jin, Small RNAs-the secret agents in the plant-pathogen interactions. Curr Opin Plant Biol 26, 87-94 (2015).