Influence of acetosyringone concentration on induction of carrot hairy root by Agrobacterium rhizogenes

Carrot hairy root induction by two different strains of Agrobacterium rhizogenesMTCC532 and MTCC2364 grown in yeast extract mannitol agar medium (YEMA) was studied in carrot (Daucus carota). The maximum hairy root induction was observed when carrot was simmered with 48 h old culture of A. rhizogenes MTCC-532. With different concentrations of acetosyringone (AS) tested, addition of 150 μM acetosyringone was found to enhance the transformation frequency up to 75(±2.60) and 60 (±2.08) percentage by A. rhizogenes MTCC-532 and MTCC 2364 strains, respectively. Transformation efficiency was highly dependent on the acetosyringone concentrations, type of bacterial strains and carrot genotype. Transfer of Ri Ti-DNA was confirmed by polymerase chain reaction (PCR) analysis, the detection of ags gene in transformed carrot hairy root. A. rhizogenes transformed hairy roots had the ability to form copious lateral roots as well as a negative geotropic growth habit in a shorter period of time. The Murashige and Skoog (MS) medium was found to be the best medium for hairy root mass multiplication, which induced high root biomass production and rapid root tip elongation.