Identification of miRNAs and their target genes in (Camelina sativa L.) ‎transcriptome

MicroRNAs (miRNAs) are endogenous and noncoding small RNA molecules with a length of 19-24 nucleotides (nts) that regulate target genes at the post-transcriptional level in plants. In this study, several miRNAs in Camelina were identified, and their potential roles were reported. Camelina with its scientific name (Camelina Sativa L.) is an oil-medicinal plant belonging to the Brassicaceae family. First the RNA was extracted from C. sativa leaf and sent to the Beijing genome institute for RNA-sequencing. Then the data were assembled denovo with Trinity software after removing the reads with lower quality than the threshold level and trimming them. Detection of miRNAs was then performed by miRDeep2 software. Accordingly, we identified 33 miRNAs from the leaf dataset, and their secondary structures were evaluated. The target genes of the detected miRNAs were identified by the psRNAtarget website. Examining the target genes showed that a total of 1415 genes are regulated by these microRNAs, which belong to several gene families with different biological functions, including the genes of proteins that bind to the Squamusa promoter, the protein kinase family, etc. Comparing the expression of microRNA carrying genes (TPM) in the two studied doubled haploid lines, showed that except for miR296 and miR474 which were more expressed in line number 1, the other miRNAs had higher expression in line number 2. Considering the lower amount of oil production in line number 1 compared to line number 2, this indicates the relationship of these two microRNAs with oil production. miR483 was not expressed in any of the lines. miR113 and miR206 had the highest expression levels among all microRNAs. The higher expression of micro RNAs in line 2 probably indicates the higher activity of the silencing mechanism at the transcription level for the target genes in this line compared to line number 1.