Verification of auxin-induced gene expression during adventitious rooting in rolB-transformed and untransformed apple Jork 9

Apple Jork 9 transformed with the rolB gene is more sensitive to IBA than an untransformed control. Study of the effects of IBA concentration and time of exposure on the Jork 9 stem discs shows the optimum time for root induction in the transformed plants was 7 h with 24.6 μM IBA, compared to 7 h with 49.2 μM IBA for untransformed stem discs. Expression of the auxin-induced adventitious rooting related oxygenase (ARRO-1) gene during adventitious rooting in rolB-transformed and untransformed apple Jork 9 has been studied. The higher expression of the ARRO-1 gene in the rolB-transformed material suggests that its expression may be rooting-specific rather than auxin-specific.