DNA UPTAKE BY IMBIBITION AND EXPRESSION OF A FOREIGN GENE IN RICE

Uptake of DNA by imbibition of dry and viable rice (Oryza sativa L.) e mbryos from a DNA solution and expression of a foreign gene were detec ted using two different vectors containing gusA (beta-glucuronidase) a nd hpt (hygromycin phosphotransferase) as reporter genes. The frequenc y of transient expression of gusA and hpt genes using the CaMV35S prom oter was about 30 to 50%. The main sites of gusA gene expression were meristems of roots and vascular bundles of leaves. Also, DNA uptake, i ntegration and expression of the hpt gene in selected rice were invest igated by various PCR methods and Southern blot analysis of genomic DN A. It was shown that the hygromycin phosphotransferase (HPT) DNA was p resent in the rice genome in an integrated form and not as a plasmid f orm.