Agrobacterial transformation of maize by in planta and in vitro methods: problems and decisions

Problems of agrobacterial transformation of maize by methods in planta and in vitro are described. Experimental data on optimization of regeneration from transformed embryogenic maize callus of the KM line are presented.

Glyphosate selection of maize transformants containing CP4epsps gene

Aim. To study the selection conditions of maize transformants containing the CP4epsps gene using glyphosate as a selective agent. Methods. Tissue culture in vitro, Agrobacterium-mediated transformation, selection of transgenic plants, isolation of total plant DNA, analysis of plant DNA by polymerase chain reaction (PCR). Results. The morphogenic maize callus of immature embryos of the hybrid (PLS61)R2×PLS61 was produced, which had a high regeneration rate (up to 95%), that persisted over long cultivation. Agrobacterium mediated transformation of the morphogenic callus and selection of the transgenic material using glyphosate yielded maize transformants containing the CP4epsps gene at a frequency of 1%. Conclusions. Maize genotype (PLS61)R2×PLS61 is promising for studies on the maize genetic transformation, in particular for the production of transgenic maize resistant to glyphosate herbicide. The use of morphogenic maize callus (PLS61)R2×PLS61 and glyphosate as a selective agent at a concentration of 0.1 mM and 0.25 mM in media for callusogenesis and 0.01 mM in the medium for regeneration was effective for the selection of transgenic plants with the gene CP4epsps. Keywords: Zea mays L., morphogenic callus, Agrobacterium-mediated transformation, PCR, genetic engineering.