Involvement of small RNAs in distinguishing symbiotic and pathogenic fungi in tomato

• Applicant: Dr. Maitree Pradhan
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 518272331

The excessive use of synthetic chemicals including fertilizers and fungicides pose a serious threat due to soil and water pollution, depleting species richness, and accumulating toxins in the food chain. Sustainable agriculture and crop productivity without such soil abuse requires novel biotechnological solutions resulting from improved molecular understanding of how plants survive in unpredictable environment and deploy natural plant allies, such as AM fungi, foracquiring resources for their growth, defence against pathogens and maximizing their Darwinian fitness. Crop productivity is often limited due to abiotic factors such as the scarcity in soil of some micro- and macro-nutrients (e.g. phosphorous), and by biotic challenges such as pathogens. These challenges are amplified by the anthropogenic impact of intensive agronomic practices in monocultures. Plants are able to respond to the environmental stresses by reprogramming theexpression of a large number of genes, which are programmed in highly regulated manner at transcriptional and post-transcriptional levels. non-coding RNAs (ncRNAs) form a novel layer of regulators of gene expression in plants as well as organisms that associate with the host, such as pathogenic and beneficial AM fungi. ncRNAs offers the potential to develop biotechnological solutions to tailor crop plants that are resilient to environmental stresses and reduce chemicalusages, thereby helping to protect the environment by developing sustainable agricultural practices. We hypothesize that both plants as well as their interacting fungi deploy the regulatory ncRNAs in transkingdom manner to communicate and control the cell programs ofeach other. Further, ncRNAs might also function as modulators of complex environmental interactions to help the plants adapt to fluctuating environment. Additionally, trans kingdom acting ncRNAs such as from AM fungi may provide the much needed tool for biotechnological interventions in agriculture for controlling pathogenic fungi and promoting plant nutrient uptake and decreasing fungicide and fertilizer usages. In this proposal, we plan to investigate the involvement of ncRNAs in the ability of plants to withstand biotic stresses and to discriminate between pathogenic and beneficial fungi. The major objective of the proposal are: 1. Unravel the dynamics of smRNA patterns during symbiotic and pathogenic fungal interaction with tomato. 2. Explore trans-kingdom smRNAs and their biological functions during pathogenic and symbiotic fungal interactions. 3. Understand AM fungi’s role in protecting host againstfungal pathogens. We propose to use a tri-trophic interaction system comprising of tomato host, Fusarium oxysporum (fusarium oxysporum f.sp. lycopersici) pathogen, and Rhizophagus irregularis AM fungi, under limited phosphorous conditions.

• DFG Programme: WBP Position