Comparison of rooting ability and miR156 and miR172 expression in juvenile (Juv), midphase (Mid) and mature (Mat) cuttings. Cuttings were excised 15, 45 or 200 cm above the ground (a), treated with auxin (20 sec deep in 6gr/l K-IBA) and incubated on rooting tables. (b) Percent rooting and callus formation after 30 days. Bars show averages and standard error. Bars with different letters are statistically different as determined by Scheffe analysis p < 0.05. (c,d) RNA was prepared from the bottom of the cuttings and miR156 and miR172 expression analysis was performed by Northern blots: (c) average and standard error of three experiments, asterisk show statistically significant difference as determined by Scheffe analysis p < 0.05. (d) representative gels.