Analysis of dynamic Argonaute protein interaction networks during plant-microbe interactions

• Applicant: Professor Dr. Gunter Meister
• Subject Area: Plant Biochemistry and Biophysics ; Biochemistry ; Plant Breeding and Plant Pathology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 433194101

host-symbiont interactions. These contacts are often mediated by double stranded RNAs (dsRNAs) that are delivered from one species to the other. This leads to reprogramming of small RNA regulatory networks with consequences for the host but also for the pathogenic or symbiotic invader. When longer dsRNA forms enter the cell, they are processed by a cellular Dicer enzyme (termed Dicer-like or DCL in plants), and actively loaded onto a member of the Argonaute protein family - a process commonly referred to as Argonaute or RISC loading (RNA-induced silencing complex). It is, however, unclear how such invading RNAs are loaded and which Argonaute and thus gene silencing pathway is chosen. We will use a biochemical approach to provide insights into this largely unsolved aspect of cross-kingdom RNAi. We will use different experiments systems and isolate the respective Argonaute proteins from pathogenic or symbiotic invaders as well as the host plants. We will characterize the small RNA as well as the potential target RNA landscape of Argonaute complexes. Furthermore, remodeling of Argonaute protein networks as well as changes in post-translational modification patterns will be addresses as well. Finally, we will contribute our expertise with in vitro functional assays and develop an Argonaute loading assay that allows for the study of small RNA loading and also unloading, which is highly relevant for cross-kingdom RNAi and also the use of dsRNA as fungicide.

• DFG Programme: Research Units
• Subproject of: FOR 5116: “exRNA”: Plant-microbe communication through extracellular RNA