TRANSFORMATION OF MAIZE EMBRYOGENIC CALLI MEDIATED BY ULTRASONICATIONAND REGENERATION OF FERTILE TRANSGENIC PLANTS

An insecticidal protein gene isolated from Bacillus thuringiensis was transferred into maize by using ultrasonication. The fertile transgeni c plants and their progeny were obtained. The Southern hybridization r esults indicated that the foreign gene had integrated into the maize g enome. It has been found that the acoustic intensity and the duration of treatment are the important parameters influencing transformation e fficiency by ultrasonication. The maximum relative transformation freq uency of 34.1% was achieved after 30 min oi sonication at 0.5 W/cm(2) acoustic intensity. With appropriate parameters the ultrasonication ca n make a number oi micropores formed on the cell surface and minimize the treatment damage to the foreign DNA molecules, thus facilitating t he DNA molecules to enter the cells.