Characterising genes involved in microRNA degradation in Arabidopsis

MicroRNAs (miRNAs) are small non-coding RNA molecules regulating the expression of protein coding genes by targeting mRNAs. Since they play key roles in development and in responses to both biotic and abiotic stresses, it is important that miRNAs are expressed at the right time and place. Therefore there must be a mechanism to degrade miRNAs (miRNA turnover) and this mechanism itself must be carefully regulated to ensure that miRNAs are not present when their function is not required. However, we know very little about this mechanism and its regulation. The project team will carry out a mutant screen to identify genes involved in miRNA turnover. The screening assay relies on a GFP sensor, which is targeted by a miRNA. Expression of the miRNA is induced by germinating seeds on a special media. After changing the media the miRNA transcription is switched off and the existing miRNA molecules are degraded, leading to green fluorescence recovery in the seedlings. The project will screen for lines exhibiting faster or slower GFP recovery. After validation of the mutant phenotype the mutant genes will be identified by next generation sequencing. Identifying genes involved in miRNA turnover will open up a new field in the RNA silencing area. Understanding the function of those genes and how miRNA turnover is regulated will impact on all aspects of plant biology but also on biomedicine as siRNAs are potential therapeutics. The project will run in a vibrant and dynamic research group including wet lab researchers and bioinformaticians.