TRANSGENIC FERTILE SCOPARIA-DULCIS L, A FOLK MEDICINAL PLANT, CONFERRED WITH A HERBICIDE-RESISTANT TRAIT USING AN RI BINARY VECTOR

Transgenic herbicide-resistant Scoparia dulcis plants were obtained by using an Ri binary vector system. The chimeric bar gene encoding phos phinothricin acetyltransferase flanked by the promoter for cauliflower mosaic virus 35S RNA and the terminal sequence for nopaline synthase was introduced in the plant genome by Agrobacterium-mediated transform ation by means of scratching young plants. Hairy roots resistant to bi alaphos were selected and plantlets (R0) were regenerated. Progenies ( S1) were obtained by self-fertilization. The transgenic state was conf irmed by DNA-blot hybridization and assaying of neomycin phosphotransf erase II. Expression of the bar gene in the transgenic RO and S1 proge nies was indicated by the activity of phosphinothricin acetyltransfera se. Transgenic plants accumulated scopadulcic acid B, a specific secon dary metabolite of S. dulcis, in amounts of 15-60% compared with that in normal plants. The transgenic plants and progenies showed resistant trait towards bialaphos and phosphinothricin. These results suggest t hat an Ri binary system is one of the useful tools for the transformat ion of medicinal plants for which a regeneration protocol has not been established.