Studies on the Freeze-Thaw Method of Transforming Recombinant Plasmid DNA into Agrobacterium tumefaciens

Transformation of Agrobacterium tumefaciens by the freezethaw method is modified. The frequency of transformation is improved, and a modified protocol of transformaing Agrobacterium tumefaciens with plasmid DNA is introduced. Plasmid vectors pBISP1, pBIP1, pBIAP1 and pBISgp120 are transformed into Agrobacterium tumefaciens by this modified protocol.