ACTIVITY OF CECROPIN SB37 AGAINST PROTOPLASTS FROM SEVERAL PLANT-SPECIES AND THEIR BACTERIAL PATHOGENS

The lethal concentration of cecropin SB37 was determined for protoplasts from 11 plant cultivars or experimental lines representing 7 plant species and for 9 bacterial species that are pathogens of these plants. Lethal concentrations ranged from 4.5-mu-M for tomato (Lycopersicon esculentum cv Red Cherry) to 41-mu-M for sugarbeet (Beta vulgaris REL 1). Cecropin SB37 exhibited potent antibacterial activity against all of the bacterial pathogens tested. Lethal concentrations ranged from 0.1-4.5-mu-M. The difference between the lethal concentrations of cecropin SB37 for protoplasts from certain plants and their respective bacterial pathogens suggests it may be feasible to protect against these pathogens by introducing a modified cecropin gene into the plant.