Twentyg of plant genomic DNA was digested with BglII restriction endonuclease, which cleaves at one end of the rstB gene to estimate insertion copy numbers of the transgene in the plant genome.The enzyme digestion products were separated in a 0.9% (w/v) agarose gel and blotted onto Hybond-N+nylon membrane (Amer-sham Pharmacia Biotech, Piscataway, NJ, USA)