Vol. 6, Issue 3 (2018)
Effect of acetosyringone and age of callus on Agrobacterium- mediated transformation of rice (Oryza sativa L.) calli
Author(s): GB Sawant, SV Sawardekar, SG Bhave and JK Kshirsagar
Abstract: The present investigation was carried out to standardize the age of callus (days), acetosyringone concentration (µM) and acetosyringone incubation period (min) prior to colonization for achieving highest transformation frequency (%). Scutellum-derived calli of an indica rice variety Ratnagiri-711 that was found highly regenerable in previous studies were used as explants. The disarmed hyper virulent Agrobacterium tumefaciens strain EHA 105 harboring pBinBt3 was used as vector system. Plasmid pBinBt3 contains the cry2Aa gene linked to the cauliflower mosaic virus (CaMV) 35S promoter and neomycin phosphotransferase (nptII) gene under the control of nopaline synthase (nos) promoter and terminator. Treated calli were analyzed through PCR for confirming the presence of transgene and transformation frequencies were calculated. All the three factors viz. age of calli, acetosyringone incubation period along with different concentrations were found with significant effect on transformation frequency. 35 days old calli combined with acetosyringone incubation period of 45 min prior to colonization with a concentration of 350 µM were recorded the highest transformation frequency. Acetosyringone was found as an essential key factor in achieving the rice transformation.