Insights into microRNAs and their targets associated with lignin composition in Eucalyptus camaldulensis

Abstract

MicroRNAs are non-coding RNAs which control the gene expression at post transcriptional level or inhibit the translation process based on the complementarity between microRNA and the target. A next generation sequence (NGS) approach was undertaken to study genome wide expression of microRNAs in xylem and leaves of Eucalyptus camaldulensis differing in lignin composition, namely syringyl to guaiacyl ratio (S/G ratio). Leaves had high abundance of miRNA165 and 166 while xylem sample showed high abundance of miRNA 159 and 319 in addition to miRNA 165 and 166. Differential analysis of small RNAs of xylem samples in trees with high and low S/G ratio resulted in thirty two candidates with more than two fold difference in expression levels. Among the small RNAs, microRNAs were analyzed and targets were predicted using Eucalyptus transcriptome. Computational analysis of unmapped reads to microRNA databases resulted in prediction of novel microRNAs from E. camaldulensis.