Comparative expression analysis of some miRNAs in wheat seedling

MiRNAs are known as regulatory genes in eukaryotic genomes, regulating their target genes expression. Here, we have investigated five pathogen responsive miRNAs; tae-miR156, tae-miR159, tae-miR167, tae-miR171 and tae-miR393 expression pattern in wheat Taichung 29 cultivar between day 10 to 20th of the seedling life. Since plant seedlings are mostly used for plant-pathogene interaction analysis, this research was committed to analyze the expression pattern of these miRNAs independent of pathogenesis and in 10 to 20 days old seedlings. Plants were grown in soil in greenhouse condition, and 10, 11, 13, 17 and 20 days old seedlings were harvested for RNA extraction and cDNA synthesis. QRT-PCR analysis of candidate miRNAs expression indicated that, tae-miR156 and tae-miR159 expression level has been sharply increased between day 13th to 17th and then after, decreased to the minimum level before day 20th. On the other hand, tae-miR167, tae-miR171 and tae-miR393 expression level has been gradually increased since day 13th of the growth. These data suggest that day 13th to 17th of the wheat seedling life, is crucial period of life in terms of drastic physiological changes which are affected by miRNAs expression. Since majority of the target genes of these candidate miRNAs are not known yet, their expression alterations is only suggested to be consistent with the expression of some known target genes, belong to the signaling pathway like auxin signaling. Considering sequence conservation pattern of miRNA precursors, here we suggested functional miR*s for tae-miR156, tae-miR159, and tae-miR393.