Rhizogenic, caulogenic and callogenic responses of flax leaf discs mediated by Agrobacterium tumefaciens

From three different ecological and temporal regions of Punjab, Pakistan, seven strains of Agrobacterium tumefaciens were isolated from the tumor bearing trees of Acacia modesta Wall. (AM1), Erythrina suberosa Roxb. (Erythrina indica, EI1, EI2, EI3) and Mangifera indica L. (MI2, MI3, MI4). All strains belong to biotype I and each strain harbor a single plasmid. For the demonstration of T-DNA transfer, leaf disc transformation experiments were performed using leaf discs of Flax, Linum usitatissimum L. Transfer and expression of T-DNA was depicted by the rhizogenic, caulogenic and in some cases callogenic responses of the transformed leaf discs on auxin free MS. medium. Out of the seven strains, only AM1, EI2 and EI3 were able to transform the leaf discs of flax and showed rhizogenic, caulogenic and in some cases callogenic responses. While the rest of the strains showed no positive transformation response. Auxin content of the transformed leaf discs were significantly higher than the control (without transformation) leaf discs. Protein analysis of the leaf discs and the transformed tissues, on polyacrylamide gel, revealed that transformed tissues had additional protein bands of (similar to)61 (AM1, EI2, EI3) and (similar to)72 (AM1) kd.