STABLE TRANSFORMATION OF ARABIDOPSIS WITH THE BAR GENE USING PARTICLEBOMBARDMENT

A plasmid pARK22 harbouring the bar gene encoding phosphinothricin ace tyltransferase (PAT) under the control of the cauliflower mosaic virus (CaMV) 35S promoter and nopaline synthase (NOS) terminator was constr ucted and introduced into root sections of Arabidopsis thaliana using the pneumatic particle gun. The root sections that had been bombarded with this plasmid gave four to eight times higher yield of drug-resist ant calluses than those sections bombarded with pCaMVNEO or pCH, which respectively contain the neomycin phosphotransferase and hygromycin p hosphotransferase genes. Among a number of primary transformant (T-0) plants obtained from independent bialaphos-resistant calluses, three w ere studied by Southern blot hybridization and PAT enzyme activity ana lyses, confirming the stable integration of the foreign gene into the Arabidopsis genome and its expression in plants. The progeny analysis showed transmission of the foreign gene and its expression in up to th e T-2 generation. Some of the T-1 progeny showed morphological abnorma lities. Thus, the bar gene can be used effectively to allow selection of transgenic A. thaliana plants.