Expression pattern of wheat miRNAs under salinity stress and prediction of salt-inducible miRNAs targets

Abstract

MicroRNAs (miRNAs) are non-coding small RNAs that regulate gene expression by translational repression or transcript degradation. Thus far, a large number of miRNAs have been identified from model plant species and the quantity of miRNAs has been functionally characterized in diverse plants. However, the molecular characterizations of the conserved miRNAs are still largely elusive in wheat. In this study, 32 wheat miRNAs (TaMIRs) currently released in the Sanger miRBase (the microRNA database) were selected to evaluate the expression patterns under conditions of non-stress (CK) and salt stress treatment. Based on the analysis of semiquantitative RT-PCR and quantitative real qRT-PCR, TaMIR159a, TaMIR160, TaMIR167, TaMIR174, TaMIR399, TaMIR408, TaMIR11124 and TaMIR1133 were found to have responses to salinity stress, with an upregulated pattern under salt stress treatment. Based on a BLAST search against the NCBI GenBank database, the potential targets of the salt-inducible wheat miRNAs were predicted. Except for TaMIR399 not being identified to have the putative target genes, other salt-inducible TaMIRs were found to possess 2 to 7 putative target genes. Together, our results suggest that a subset of miRNAs are involved in the mediation of salt stress signaling responses in wheat via their roles on the regulation of acted target genes at post-transcriptional and translation levels.