Transcriptome deep sequencing, identification of novel microRNAs and validation under drought stress in turmeric (Curcuma longa L.)

microRNAs (miRNAs) are small non-coding RNAs that execute regulation of gene expression at the post-transcriptional level. Information on turmeric miRNAs is very rare. In the present study, we have identified 27 conserved and 40 non-conserved miRNA families by high-throughput Illumina sequencing and downstream in silico analysis. We could also identify 97 novel candidate miRNAs specific to turmeric. Selected miRNAs were validated by stem-loop RT-PCR and northern blotting. The targets were predicted for identified miRNAs and were found to be involved in plant growth and development, stress response and metabolism. Expression pattern of selected conserved miRNAs in response to drought stress was analyzed by stem-loop qRT-PCR. This is the first report on miRNA content of turmeric transcriptome, which might serve as a foundation for more future work on miRNA based gene regulation in this medicinally important spice crop.