Transgenic plantain (cv. Harton) plants resistant to herbicide Basta obtained by electroporation

Bananas and plantains (Musa spp.) are crops of vital importance to hundreds of millions of people in developing countries. In Venezuela, for instance, plantain represents one of the most socio-economically important crops. In order to improve the crop profitability, besides controlling nematodes, insects, fungi, bacteria and virus attack, it is also necessary to develop an efficient weed control method to decrease the incidence of pests and diseases. In this research we establish suitable parameters to obtain Basta (herbicide) resistant plants through electroporation of plantain shoot apices with plasmid pCAMBIA 3201 carrying the gene bar, which codifies for the enzyme phosphinothricin acetyl transferase, giving resistance to phosphinothricin, the active compound of the Basta herbicide. Initially, shoot apices were isolated and grown on Murashige and Skoog medium for 3 days under dark conditions, the tissue was pretreated with three hourly washes using buffer at pH 7.6, and then it was incubated along with plasmid pCAMBIA 3201, on the same buffer. Electroporation was performed applying 200 V/cm discharge from a 1000 mu F capacitor. This protocol ensures high electroporation efficiency, less tissue recuperation time and greater percent of regenerated plants. Plasmid incorporation was traced using GUS as reporter gene, selection assays using Basta as selective agent, and PCR analysis. The minimal inhibitory concentration of Basta was 1 mg/ml.