Expression profile of miRNAs in leaf and root. Expression of miR167, miR169, miR319, miR414, miR164 and miR398 in young leaf (Y), old leaf (O) and root (R) was detected using SL RT-PCR. 18sRNA was used as the internal control to equalize cDNA quantity. Each bar in the diagram corresponds to the IDV of the intensity of the individually amplified band in the gel. A least significant difference test was employed to test the relative expression levels of miRNAs. The data are presented as mean±standard deviation (n=3). Same number of asterisks above error bars represents non-significant difference and different number of asterisks represents significant difference, P<0.05.