Absorption, transport and metabolism of 6-benziladenine in Hyacinthus amethystina cv. Albus explants

Abstract

Bulb scale explants of Hyacinthus amethystina cv. Albus (pirenaic hyacinth), cultivated in medium MS, supplemented with 4.90 mM and 22.19 mM of 6-Benziladenine (BA) of IBA were utilized in order to study the absorption, distribution and metabolism of BA. The explants were cultivated in two different positions in relation to their polarity: dorsal and ventral. Also, each explant sample was divided in two parts: basal and apical. The explants were cultivated in the presence of 8-(¹⁴C)-BA with specific activity of 2.0 GBq/mmol, which was added to the medium in quantity so that each growing recipient had an activity of 940 KBq. The samples for analysis were cultivated during a period 1, 12, 36 and 72 hours. A positive relationship between BA distribution and explant growth in pirenaic hyacinth was found. Most of the BA was absorbed during the first 36 hours of cultivation and, although there was higher growth in the explant to medium contact zone, the absorbed BA was transported to distinct explant parts, which varies with the polarity of the cultivation. There was a positive relationship between the position of the growing explant, the growing regulator metabolism, the content of considered active forms of BA and the morphogenic responses.