Transformation of tomato using biolistic gun for transient expression of the -glucuronidase gene

Abstract

We report for the first time, conditions for the biolistic transformation of tomato for the introduction of �-glucuronidase gene ( gusA ) into different explants viz., shoot tips, hypocotyls and cotyledons of genotype IPA-3. The respective per cent plant regeneration in different explants was 95.16, 79.30 and 90.14% on MS media supplemented with BAP (2.0 mg L -1 ) and Kn (1.0 mg L -1 ). The influence of physical parameters of particle gun on rates of transient GUS expression have been investigated viz., quantity of DNA, distance between the microcarrier launch assembly and target tissues; and the biological factors associated with the target tissues i.e., effect of osmoticum (mannitol), pre-bombardment culture period and postbombardment culture period. Maximum GUS expression of 25.00, 33.00 and 22.20% was respectively recorded when 10-dold shoot tips, hypocotyls and cotyledons were bombarded with 18 μL of DNA suspension. A firing distance of 7.5 cm was found to be most suitable recording 34.12, 36.56 and 22.69% transient GUS expression in shoot tips, hypocotyls and cotyledons, respectively. Addition of osmoticum into the culture medium reduced per cent GUS expression significantly in all the explants even at 1 molar concentration. Pre-culture of explants prior to bombardment also deduced the transformation efficiency, however post bombardment culture period of one day resulted in maximum GUS expression in all the explants.