Involvement of microRNAs in Miscanthus development

K Farrar & MJ Wilkinson

Micro RNAs (miRNAs) and short interfering RNAs (siRNAs) represent major recent discoveries in plant development. They provide an RNA-based system of gene regulation that is conserved throughout eukaryotes. In plants, miRNAs and siRNAs promote degradation of specific messenger RNAs of genes encoding for control of various aspects of plant development, including developmental timing, lateral organ formation and stem cell maintenance and as such are of considerable interest to understanding the growth and development of the dedicated perennial biomass crop Miscanthus. These processes operate alongside another mechanism of gene regulation mediated by the methylation of regions of genomic DNA associated with DNA transcription. Little is known about how these systems interact. However, both are likely to be most active amongst perennial plants that show high levels of phenotypic plasticity.  Numerous miRNAs identified in Arabidopsis have subsequently been discovered in other plant species, including the C4 grasses Sorghum bicolor and Zea mays, implying that orthologues of these genes are highly likely to be present and functional in Miscanthus. Identification of homologues of miRNAs and their putative target genes in Miscanthus allows the study of the extent of cross-talk between miRNA and methylation-mediated control of expression. This would lead to a greater understanding of the molecular basis of plasticity in Miscanthus; especially for the economically important aspects of plant development and biomass accumulation.  This project would provide training in bioinformatics, emergent technologies associated with miRNA function, in forward genetics (BAC library production and use, microsynteny) and DNA methylation detection (e.g. bisulfite sequencing, mdAFLP), grass physiology and in the strategies most likely to lead to improvement of the novel biomass crop Miscanthus for bioenergy production. The suitable candidate would therefore have the opportunity to develop the project in a number of different directions and because of the emergent nature of the field, their work has the capacity to produce high impact publications.