Agrobacterium rhizogenes mediated genetic transformation resulting in hairy root formation is enhanced by ultrasonication and acetosyringone

The phytopathogenic bacteria Agrobacterium rhizogenes
genetically transforms plants by transferring a portion
of the resident Ri plasmid, the T-DNA to the plant.
Plant species differ in their temporal competence for
transformation. But various physical and chemical
*Corresponding author
methods are found to enhance transformation
frequency. Agrobacterium rhizogenes mediated
transformation efficiency was assessed under the
influence of sonication, calcium treatment,
acetosyringone and macerating enzymes in suitable
combinations in Nicotiana tabacum as a model system.
Manual wounding resulted in 21% transformation
frequency. Where as sonication resulted in 2.2 fold
increase, followed by sonication with CaCl2 treatment
resulted in 2.5 fold increase and sonication with
acetosyringone treatment resulted in 4.1 fold increase in
transformation frequency. However, sonication with
macerating enzyme treatment resulted in 1.5 to 5.25-
fold decrease in transformation frequency. Micro
wounding through sonication followed by
acetosyringone treatment enhanced transformation
frequency substantially. The results of this study may be
very useful in genetic manipulation of plants by
Agrobacterium rhizogenes mediated gene delivery to
higher plants, which are recalcitrant to A. tumefaciens
mediated genetic manipulation.