A sunflower antifungal peptide active against Sclerotinia sclerotiorum

REGENTE MR; OLIVA CR; FELDMAN ML; CASTAGNARO A; DE LA CANAL L

PHYSIOLOGIA PLANTARUM

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 1997 vol. 100 p. 178 - 182

0031-9317

A 5-kDa antifungal peptide (APS) was isolated from Helianthus annum L. (line HA89) leaves infected with a virulent isolate of Sclerotinia sclerotiorum (Lib.) de Bary. AP5 was purified by gel filtration, cation exchange chromatography and reverse phase FPLC and HPLC. This peptide in vitro inhibits ascospores germination of the fungal pathogen S. sclerotiorum or produces mycelial growth inhibition, depending on its concentration. The effective concentration of AP5 giving 50% growth inhibition (IC50) against S. sclerotiorum was 0.4 μM. The antifungal efficacy of AP5 is higher than that of other antimicrobial proteins already described that have no appreciable effect on S. sclemtiorum below 4 μM. The relevance of this finding with regard to the function of AP5 in sunflower resistance to pathogens is discussed