Routine transformation of rapid cycling cabbage (Brassica oleracea) - molecular evidence for regeneration of chimeras

Abstract

We have developed a transformation procedure using both disarmed and wild-type Agrobacterium tumefaciens strains for a rapid-cycling cabbage genotype (Brassica oleracea var. capitata). This method is based on the fact that the wild-type A. tumefaciens strain (82.139) can induce shooty tumors in rapid-cycling cabbage. No special regeneration medium was required and no selection pressure was exerted at any stage of the transformation procedure; the transformants were identified by screening for β-glucuronidase (GUS) activity with a histological assay. Southern analyses ascertained that the GUS-expressing plants contained the T-DNA carried by the disarmed strain but not the T-DNA of the wild-type A. tumefaciens strain. One transgenic plant was obtained for an average of 25 plants inoculated. Southern analysis showed that most of the transgenic plants, under these non-selective conditions, proved to be chimeric. Regeneration was established to be of pluricellular origin. The transgenic plants transmitted their T-DNA inserts to the progeny. © 1994.