System analysis of differentially expressed miRNAs in hexaploid wheat display tissue-specific regulatory role during Fe deficiency response

Iron (Fe) deficiency in soil could largely affect crop productivity but the molecular mechanisms underlying the regulation of Fe deficiency response are still limited. Specifically, microRNA (miRNA) mediated regulation of Fe deficiency genes and the network is poorly understood. In the current work, we aim to understand the molecular mechanisms of Fe deficiency response in wheat seedlings by generating an inventory of differentially expressed miRNAs. Stem loop quantitative RT PCR analysis suggested the expression of these miRNAs in a spatio-temporal fashion, with few showing time-specific expression responses. Furthermore, miRNA target prediction analysis suggested that few of these miRNA could specifically target genes such as multicopper oxidases, E3 ubiquitin ligases, GRAS family and WRKY transcription factors known to be involved in Fe homeostasis. Our work provides insights into miRNA-mediated regulatory pathways during Fe deficiency response. The first information generated here will help to identify the candidate genes for genetic improvement of Fe deficiency tolerance in hexaploid wheat.