บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Identification and characterization of a hexapeptide with activity against phytopathogenic fungi that cause postharvest decay in fruits.

Lopez-Garcia, B.; Gonzalez-Candelas, L.; Perez-Paya, E.; Marcos, J. F.;

Molecular Plant-Microbe Interactions Year: 2000 Vol: 13 Issue: 8 Pages: 837-846 Ref: 46 ref.

2000

บทคัดย่อ

Identification and characterization of a hexapeptide with activity against phytopathogenic fungi that cause postharvest decay in fruits.

A hexapeptide of amino acid sequence Ac-Arg-Lys-Thr-Trp-Phe-Trp-NH2 was demonstrated to have antimicrobial activity against selected phytopathogenic fungi that cause postharvest decay in fruits. The peptide synthesized with either all D- or all L-amino acids inhibited the in vitro growth of strains of Penicillium italicum, P. digitatum, and Botrytis cinerea, with MICs of 60 to 80 micro M and 50% inhibitory concentration (IC50) of 30 to 40 micro M. The inhibitory activity of the peptide was both sequence- and fungus-specific since (i) sequence-related peptides lacked activity (including one with five residues identical to the active sequence), (ii) other filamentous fungi (including some that belong to the genus Penicillium) were insensitive to the peptide's antifungal action, and (iii) the peptide did not inhibit the growth of several yeast and bacterial strains assayed. Experiments on P. digitatum identified conidial germination as particularly sensitive to inhibition although mycelial growth w

as also affected. These findings suggest that the inhibitory effect is initially driven by the electrostatic interaction of the peptide with fungal components. The antifungal peptide retarded the blue and green mould diseases of citrus fruits and the gray mould of tomato fruits under controlled inoculation conditions, thus providing evidence for the feasibility of using very short peptides in plant protection. This and previous studies with related peptides indicate some degree of peptide amino acid sequence and structure conservation associated with the antimicrobial activity, and suggest a general sequence layout for short antifungal peptides, consisting of one or two positively charged residues combined with aromatic amino acid residues.