Antifungal Activity of a Synthetic Cationic Peptide against the Plant Pathogens Colletotrichum graminicola and Three Fusaritum Species

A small cationic peptide (1118944) was tested for activity against a number of pathogens of agricultural crops. JH8944 inhibited conidium growth in most of the tested plant pathogens with a dose of 50 mu g/ml, although one isolate of Fusarium oxysporum was inhibited at 5 mu g/ml of JH8944. Most conidia of Fusarium graminearum were killed within 6 hours of treatment with 50 mu g/ml of JH8944. Germinating F. graminearum conidia required 238 mu g/ml of JH8944 for 90% growth inhibition. The peptide did not cause any damage to tissues surrounding maize leaf punctures when tested at a higher concentration of 250 mu g/ml even after 3 days. Liposomes consisting of phosphatidylglycerol were susceptible to leakage after treatment with 25 and 50 mu g/ml of JH8944. These experiments suggest this peptide destroys fungal membrane integrity and could be utilized for control of crop fungal pathogens.