title: Comparison of the Antimicrobial Properties of Chitosan Oligosaccharides (COS) and EDTA against Fusarium fujikuroi Causing Rice Bakanae Disease.
abstract: Bakanae disease is a destructive rice disease in South Korea caused by Fusarium fujikuroi infection. Chemical fungicides have been used to manage the disease, but the emergence of fungicide-resistant strains has gradually increased. Two chelating agents, chitosan oligosaccharides (COS) and ethylenediaminetetraacetatic acid (EDTA), are well known as biosafe and biocompatible antimicrobial agents. In this study, we compared the actions of COS and EDTA to gain a better understanding of the underlying antimicrobial activities and to evaluate them as eco-friendly fungicides against F. fujikuroi. While COS exhibited a rapid fungicidal effect on hyphal growing cells within 5 min, EDTA had a fungistatic effect on reversible growth inhibition. Scanning electron microscopy revealed that COS treatment resulted in pore-formation and cellular leakage along the growing hyphae, whereas EDTA caused no significant morphological changes. COS activity was greatly suppressed by the addition of Ca(2+) to the medium, and EDTA action was largely suppressed by Mn(2+) and slightly by Ca(2+), respectively. Taken together, these results indicated that two chelating agents, COS and EDTA, have different modes of antimicrobial action on F. fujikuroi. Thus, the combination of chelating agents having different modes of action might be an effective disease management strategy to prevent or delay the development of fungicide-resistant strains.
authors.affiliation: Division of Science Education and Institute of Fusion Science, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
authors.forename: Seung Won
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Life Science, College of Bio-nano, Gachon University, Seongnam, 461-701, Republic of Korea.
authors.forename: Jae Kweon
authors.initials: JK
authors.lastname: Park
authors.affiliation: Division of Science Education and Institute of Fusion Science, Chonbuk National University, Jeonju, 561-756, Republic of Korea.
authors.forename: Cho Heun
authors.initials: CH
authors.lastname: Lee
authors.affiliation: National Academy of Agricultural Science, Rural Development Administration, Jeonju, 560-500, Republic of Korea.
authors.forename: Bum-Soo
authors.initials: BS
authors.lastname: Hahn
authors.affiliation: Division of Science Education and Institute of Fusion Science, Chonbuk National University, Jeonju, 561-756, Republic of Korea. jkoo@jbnu.ac.kr.
authors.forename: Ja Choon
authors.initials: JC
authors.lastname: Koo
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D048271:Chitosan / Q000494:pharmacology*; D004492:Edetic Acid / Q000494:pharmacology*; D005670:Fusarium / Q000187:drug effects*; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology* / Q000628:therapy*
chemical_list: D000890:Anti-Infective Agents; D048271:Chitosan; D004492:Edetic Acid
keywords: Antimicrobial activity; Chitosan oligosaccharide; EDTA; Fusarium fujikuroi