FOR 5116:  “exRNA”: Plant-microbe communication through extracellular RNA

Recent reports have shown the occurrence of bi-directional trafficking of extracellular (ex) RNAs between host plants and microbes in the context of infection. These exRNAs can have significant implications on the establishment and progression of the interaction. While cross-kingdom (ck) RNA transfer from microbes to the plant can inhibit host immunity genes, host plant RNAs can impede the expression of virulence- or pathogenicity-related genes. However, only a few exRNAs (the tip of the iceberg) have been characterized to date, leaving the function(s) of the vast majority of exRNAs unexplored. At a mechanistic level, the exRNAs from both, the plant and the pathogen, can be transported as RNAs alone, bound to RNA-binding proteins (RBPs), or associated with membrane-surrounded extracellular vesicles (EVs, evRNAs). How RNAs are selected and sorted for transport, and how they are transferred to recipient cells, e.g. of other organisms, is not well understood. Our central hypothesis is that communication via exRNA is a common phenomenon in diverse plant-microbe interactions and is based on conserved biological mechanisms. Thus, elucidating these mechanisms has a high potential for improving plant productivity and health. This consortium has the joint goal of developing a mechanistic understanding of exRNA communication between plant hosts and pathogenic as well as beneficial microbes. More specifically, we plan to (i) assess the routes of ckRNA transfer between plants (including the experimental model plant Arabidopsis thaliana and important crop species) and several pathogenic or beneficial microbes (bacteria and fungi), (ii) discover the key factors involved in selection, sorting and transport for exRNAs and ckRNA transfer, and (iii) identify the molecular targets and functional effects of exRNAs and ckRNA transfer in recipient cells. To reach this goal, the consortium unites experts with advanced knowledge in the fields of non-coding RNA, RNA transport, RNA-protein interaction, RNA-mediated cross-kingdom communication and EV biology, including plant pathologists, mycologists, molecular and cell biologists, biochemists, and bioinformaticians.

DFG Programme Research Units

International Connection France

• Analysis of dynamic Argonaute protein interaction networks during plant-microbe interactions (Applicant Meister, Gunter )
• Beneficial RNA interference in model and crop plants (Applicant Secic, Ena )
• Bioinformatic methods for the investigation of cross-kingdom RNA communication (Applicant Goesmann, Alexander )
• Characterization of fungal cross-kingdom RNAi in arbuscular mycorrhiza symbiosis (Applicant Gutjahr, Caroline )
• Coordination Funds (Applicant Kogel, Karl-Heinz )
• Coordination Funds (Applicant Kehr, Julia )
• Cross kingdom exRNA transfer in the Ustilago maydis/corn pathosystem (Applicant Feldbrügge, Michael )
• Exploring the cross-kingdom RNA interference landscape in the barley-powdery mildew interaction (Applicant Panstruga, Ralph )
• RNA communication in a mutualistic microbe-plant interaction: Molecular targets and biotechnological strategies for improved crop plant production (Applicant Kogel, Karl-Heinz )
• The role and transport mechanism of extracellular RNAs in the Verticillium - Brassica interaction (Applicant Kehr, Julia )
• The role of Hfq and exRNAs in plant infections with Xylella fastidiosa (Applicant Robatzek, Silke )
• Tomato-induced cross-kingdom RNA interference in the fungal pathogen Botrytis cinerea (Applicant Weiberg, Arne )
• Vesicle-mediated RNA transfer: from factors and mechanisms to functions (Applicant Schäfer, Patrick )

Spokesperson Professorin Dr. Julia Kehr