GENETIC-TRANSFORMATION OF MATURE TAXUS - AN APPROACH TO GENETICALLY CONTROL THE IN-VITRO PRODUCTION OF THE ANTICANCER DRUG, TAXOL

This report demonstrates genetic transformation of two Taxus species, Taxus brevifolia and Taxus baccata, and expression of bacterial genes transferred into the plant genome by Agrobacterium tumefaciens. We used two strains of Agrobacterium tumefaciens (Bo542 and C58) to inoculate shoot segments of mature yew trees. The highest gall formation frequency (28.3%) was achieved with Taxus baccata using the Bo542 strain. Agrobacterium tumefaciens strain Bo542 induced significantly more galls (24%) than strain C58 (4%). Although we were able to induce tumors on both Taxus species, Taxus baccata showed significantly higher susceptibility (14%) than Taxus brevifolia (7%). In contrast to untransformed callus cultures, the gall cell lines proliferated on phytohormone-free medium and produced agropine as the result of T-DNA transfer. Southern blot analysis showed the presence of T-DNA sequences in the genome of these cell lines. Taxol and related taxane produced by the transgenic callus cultures were identified by mass spectrometry and immunoassay with monoclonal antibodies specific for taxol.