Figure 1. Gene cloning and transformation analysis.

a. Construction of pPCV701-AB. Plant expression vector of pPCV701 has been described in details by Koncz et al. 1987. This diagram shows the insertion of the A and B genes under the mas P1 and P2 promoter regions using the SalI and BamHI cutting sites, resulting in the formation of pPCV701-AB. Primer 14 and primer 21, used for detection of mRNA (primer extension), are also indicated. Reverse transcription of primer 14 produced a 293 bp fragment; reverse transcription of primer 21 produced a 205 bp fragment. The g7pA and OcspA regions are the transcription termination regions.

b. Southern hybridisation of A and B gene transformed tomato plants. Lane 1, 2, 3, 4, 5, 6, and 9 represent the genomic DNA samples from tomato plants 1, 2, 3, 4, 5, 6, and 9 transformed with pPCV701-AB. Lane C was the genomic DNA sample from a non-transformed plant. Two µg of genomic DNA of each sample was digested by BamHI and separated by 0.6% agarose gel electrophoresis; 10 pg of purified B gene fragment was loaded in lane M as positive control. Labelled B gene fragment was used as probe.