Taxus sumatrana (Miq) de Laub crown galls and hairy roots were induced by infecting stem and leaf segments with Agrobacterium tumefaciens strain A281, and A. rhizogenes strains AR1600 and ATCC15834. Results showed great variations in the transformation efficiencies among different Agrobacterium strains and T. sumatrana clones. Strain A281 had better transformation ability than
strains AR1600 and ATCC15834 (42.3 vs. 15.1~19.2%). Among all 7 clones, clones E7 and NJR had the highest transformation efficiency of both crown gall and hairy root formation, whereas the lowest transformation rates occurred with clones E2 and J85 which developed no hairy roots when inoculated with strain AR1600. Some hairy roots formed callus tissues, like crown galls, which grew rapidly and produced taxanes when cultured on plant growth regulator-free medium. The integration of Agrobacterium iaaM and rol B genes into the crown gall and hairy root genome was verified with a PCR. After 40 d of culture, growth indexes (ratio of net fresh weight of cultures to initial weight) of crown galls, hairy roots, and hairy root calli (3.9~5.5) were higher than those of untransformed calli (2.5) and roots (0.31). Transformed crown galls and calli formed from hairy roots produced more 10-deacetyl baccatin III, baccatin III, and paclitaxel than did hairy roots. After 30 d of culture in liquid medium, growth indexes of crown galls and hairy roots were 8.13 and 6.03,respectively, which were better than those on solid medium, suggesting that this system has the potential for large-scale bioreactor culture in the uture.