Meta-topolin, an alternative to benzyladenine in tissue culture?

The metabolism and the in vitro effects of the cytokinin N-6-(3-hydroxybenzyl)adenine (meta-topolin, mT) were compared with those of N-6-benzyladenine (BA), N-6-benzyl-9-(2-tetrahydropyranyl)adenine (BPA) and N-6-benzyladenine-9-riboside ([9R]BA) in micropropagated Spathiphyllum floribundum Schott cv. Petite. In vitro, BA, BPA and [9R]BA were mainly converted into the stable derivative N-6-benzyladenine-9-glucoside ([9G]BA), located at the basal part of the plant. N-6-(3-O-beta-D-glucopyranosyl)benzyladenine-9-riboside {(OG)[9R]mT} was the main derivative of mT. This new cytokinin-O-glucoside, which was present in all plant parts, was metabolized much faster than [9G]BA during acclimatization. The effect of BA and mT on in vitro shoot and root production and post vitro rooting was compared. Only mT combined a good shoot production with in vitro root formation. The plants that developed on medium with 10 mu M or more mT rooted better during acclimatization than those developed on medium with equimolar concentrations of BA.