SYNERGISTIC EFFECT OF CEFOTAXIME AND TIMENTIN TO SUPPRESS THE A GR OB A CTERIUM OVER GROWTH IN WHEAT (Triticum aestivum L.) TRANSFORMATION

摘要

The inhibitory effects of antibiotics, cefotaxime and timentin were assessed on Agrobacterium growth in wheat mature and immature embryo-derived calli. Agrobacterium tumefaciens strain, EHA105, harboring binary vector pCAMBIA3301 containing uidA (gus)and bar marker genes under cauliflower mosaic virus 35S promoter and terminator, was used in the present study. The infected calli post co-cultivation were exposed to 0 to 600 mg/L concentrations of cefotaxime and timentin. Agrobacterium persisted at 100 mg/L concentration of both antibiotics and no viable explant observed. At higher concentration, 600 mg/L of both antibiotics reduced the callus induction efficiency, however, no proliferation of Agrobacterium found. The effective combination of antibiotics for the complete elimination of bacterium was observed using cefotaxime (500 mg/L) and timentin (300 mg/L) with enhanced callus fresh weight. This combination was used for both explants in washing solution and callus induction medium. Later in sub-culturing medium, the antibiotic concentrations were reduced to 250 and 150 mg/L for cefotaxime and timentin respectively and found effective to suppress the Agrobacterium growth. Thus, the identified combination of antibiotics will be very useful in wheat transformation studies to improve transformation efficiency through Agrobacterium-mediated transformation.