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The insecticidal protein gene in the pKL-20-1 clone derived from Bacillus thuringiensis serovar. kurstaki plasmid was subcloned in the plant shuttle vector, pGA643. The 7.3 kb fragment was cloned in the BglII and Hpal sites of pGA643 vector and expressed in E. coli S17-1, which produced insecticidal proteins killing Bombyx mori larvae. The clone was named pHL-20. The protoplast formation, calli induction and plantlet regeneration of Nicotiana tabacum was carried out. A tremendous number of mesophyll protoplasts of N. tabacum were formed, up to 7105 protoplast per ml, for 20 hours in darkness in the enzyme solution of 0.5% cellulase and 0.1% macerosin, pH 5.8. The viabilities of the protoplasts were maintained above 80% for 6 days in the media containing 2mg/1 of NAA and 1mg/1 of kinetin. Calli were induced from the protoplasts and leaves of the N. tabacum on MS medium containing 0.5mg/1 BAP. Under the culture conditions the protoplasts underwent repeated cell division into calli. Plantlets were regenerated from callus cultures derived from protoplast and leaves. Shoots were induced in a medium containing 1mg/1 of BAP.