Targeting microRNAs for Destruction in Crop Plants By Short Tandem Target Mimic (STTM)

Small RNAs, including miRNAs and small interfering RNAs (siRNAs), play central roles in growth and development, epigenetics, genome integrity, defense against viral infection, and responses to environmental changes in plants. miRNAs are especially important in controlling plant development, productivity, and defense against biotic and abiotic stresses by negatively regulating gene expression at the post-transcriptional level. Hundreds to thousands of miRNAs have been identified from different plant species; and there are increasing interests and efforts in miRNA discovery with the advent of high-throughput sequencing and the completion of whole genome sequences. Despite the essential regulatory role of miRNAs in a large variety of important physiological processes, a systematic analysis on miRNA functions has not been accomplished due to a lack of tools to effectively knock down miRNA levels. Recently, a new technology called Short Tandem Target Mimic (STTM) that can target specific miRNAs of interest for destruction without affecting other miRNAs, has been developed. This robust technology will allow us to generate a much-needed miRNA knockdown collection, which is a critical step towards understanding of miRNA functions, especially in economically important crops. The current study aims at dissecting the function and evolution of miRNAs in plants, focusing on crops of significance such as, rice, tomato and soybean, in these functional analyses, but will also take advantage of knowledge gained from the model plant Arabidopsis.