Optimization of soybean embryogenic suspension cv. Jack with 606ASA2 promoter using particle bombardment

Abstract

The anthranilate synthase genefroma tobacco suspension culturehasa 606bp fragment in its promoter region that was tusedwith the GUS gene to use in transient expression assays in order to compare the performance of the Hehum PDS/1000 Device and Partícle Inflow Gun (PIG) in soybean embryogenic suspension cultures ofthe cv. Jack. The histochemical and fluorimetric enzymatic assay for GUS activity was carried out in embryos 2 days after bombardment. In most treatments the results from the histochemical and enzymatic assays were similar. The best conditions for the HeliumPDS-1000 were1100psi, 13 cmflying distance,1 mg of gold and 1 ugofDNAper shot. For the PIG 80psi,1 mgofgold and 13 cm target distance were the optimal conditions. The brief sonication of DNA suspension just before shooting increased the transient expression levei. The sodium acetate DNA precipitation methodology was as effective as the CaC^/spermidine method and was quicker. When both guns were compared with their optimal conditions, the HehumPDS-1000 showed higher performance around 25% than the PIG using gold particles. Although the PIG wasless effective than the Helium PDS/1000, it showedre producibihty and is a less expensive option.