GROWTH AND TROPANE ALKALOID PRODUCTION IN AGROBACTERIUM TRANSFORMED ROOTS AND DERIVED CALLUS OF DATURA

Small callus pieces excised from the Agrobacterium transformed root li ne D-2 of Datura stramonium, were cultured onto solidified MS medium s upplemented with a 1.0 mu M kinetin and three different concentrations (0.1, 0.5, and 1.0 mu M) of 2,4-dichlorophenoxyacetic acid (2,4-D), a nd were examined for their alkaloid productivity in relation to organi zation level and growth rate. Growth of transformed roots (in a MS liq uid medium without plant growth regulators) was greater than that of t ransformed calli excised from them and cultured separately. The additi on of 1.0 mu M 2,4-D to the culture medium had a positive effect on ca llus biomass production, while it inhibited root formation by this tis sue (the lower the 2,4-D concentration in the medium the greater the n umber of roots which emerged from the calli). Hyoscyamine production w as also higher in the transformed roots than in the transformed calli, and in these tissues the production of hyoscyamine was positively cor related with organogenesis index (i.e. its ability for rooting). At th e same time, the epoxidation of hyoscyamine to scopolamine only took p lace in the transformed calli. This occurred to a greater extent at th e lower concentrations of 2,4-D in the culture medium. The mode throug h which the 2,4-D could control the alkaloid production of transformed callus is discussed.