TRANSFORMATION OF ERWINIA-CAROTOVORA SSP. ATROSEPTICA WITH THE GREEN FLUORESCENT PROTEIN GENE FROM AEQUOREA-VICTORIA

Erwinia carotovora ssp. atroseptica has been transformed with the gree n fluorescent protein (GFP) gene from Aequorea victoria. Transformants had very high levels of GFP expression but some plasmid instability w as apparent when bacteria were not grown on ampicillin. Confocal micro scopy showed variation between cells in the level of expression of GFP . Transformants retained their pathogenicity on potatoes, rotting tube rs and causing typical blackleg symptoms when inoculated into stems, b ut the level of fluorescence was not suitable for observing bacterial movement. In contrast, E. coli producing GFP could be used to follow b acterial movement within vascular tissue of potato leaves.