Exogenous CK treatment increased the cambial stem cell activity and dormancy bud formation. (A) Phenotype of the cambial stem cells of storage roots of 2-year-old P. ginseng (Yeonpung) treated with Kinetin (0.1 mM, 0.25 mM, 0.5mM, 1mM) and Mock for 10 weeks. Scale bar = 100 μm. (B) The numbers of cambial stem cells in the cambial cell layer zone (CZ). Error bars represent standard error (n = 10). Different lowercase letters indicate statistically significant differences P < 0.05; one-way ANOVA, followed by Tukey's multiple range test. (C, D) Representative images of bud samples with mock (Sunwon) (C) and treated with BAP (0.1 mM, 0.25 mM, 0.5 mM and 1 mM/ D) for 10 weeks. Red arrows are buds. (upper panel) and cross-section image (lower panel). Scale bar = 0.5. (E) The numbers of buds which are presented in (D). Error bars represent standard error (n = 5). Different lowercase letters indicate statistically significant differences P < 0.05; one-way, followed by Tukey's multiple range test.