Identification of miRNAs and their target genes in developing seeds of soybean by deep sequencing

In our study, small RNA library and degradome library were constructed from developing soybean seeds for deep sequencing. We identified 26 new miRNAs in soybean by bioinformatic analysis, and further confirmed their expression by stem-loop RT-PCR. The miRNA star sequences of 38 known miRNAs and 8 new miRNAs were also discovered, providing additional evidence for the existence of miRNAs. Through degradome sequencing, 145 and 25 genes were identified as targets of annotated miRNAs and new miRNAs, respectively. Many identified miRNA targets may perform functions in soybean seed development by GO analysis. Additionally, soybean homolog of Arabidopsis SUPPRESSOR OF GENE SLIENCING 3(AtSGS3) was detected as target of the new identified miRNA Soy_25, suggesting presence of feedback control of miRNA biogenesis Overall design: sample 1: Examination of small RNA in soybean seed sample 2: identification of miRNA targets in soybean seed