Potent and specific bactericidal effect of juglone (5-hydroxy-1,4-naphthoquinone) on the fire blight pathogen Erwinia amylovora.

Abstract

A screening of plant quinones for inhibiting effects on the bacterial fire blight pathogen Erwinia amylovora was performed. The most active compound, juglone from walnuts, has a potent and specific bactericidal effect on E. amylovora and minimal inhibitory concentrations of only 2.5-10 μM, with stronger effects at lower, but still physiological, pH values. In vitro tests with juglone and inoculated flowers of apple (Malus domestica) showed an efficacy of 67% in preventing infection. In two years of field tests juglone had variable degrees of efficacy ranging from 40 to 82%, seemingly due to environmental conditions. A phytotoxic reaction to juglone, which is known for its allelopathic effect on plants, was restricted to browning of petals; later fruit russeting was not observed. Juglone is a promising candidate for the development of a new environmentally friendly plant protectant to replace the antibiotic streptomycin currently used in fire blight control.

• Authors: Thilo Christopher Fischer, Christian Gosch, Beate Mirbeth, Markus Gselmann, Veronika Thallmair, Karl Stich
• Journal: Journal of agricultural and food chemistry (J Agric Food Chem) Vol. 60 Issue 49 Pg. 12074-81 (Dec 12 2012) ISSN: 1520-5118 [Electronic] United States
• PMID: 23163769 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Agrochemicals
• Anti-Bacterial Agents
• Naphthoquinones
• Quinones
• juglone

Topics

• Agrochemicals (pharmacology)
• Anti-Bacterial Agents (pharmacology)
• Drug Evaluation, Preclinical
• Drug Stability
• Erwinia amylovora (drug effects, pathogenicity)
• Flowers (drug effects, microbiology)
• Germination (drug effects)
• Hydrogen-Ion Concentration
• Malus (drug effects, microbiology)
• Microbial Sensitivity Tests
• Naphthoquinones (pharmacology)
• Plant Diseases (microbiology, prevention & control)
• Quinones (chemistry, pharmacology)
• Toxicity Tests (methods)