• Research in Plant Disease
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• v.15 no.2
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• pp.112-119
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• 2009

We discovered two novel phytotoxins produced by the pathogenic fungus, Botrytis cinerea. Among the twenty-five B. cinerea isolates, which were obtained from various host plants in 1994 and 1996, twenty-two showed strong or moderate pathogenicity on five plants such as cucumber, tomato, red pepper, tobacco and Chinese cabbage. The culture filtrate of the B. cinerea 2-16 strain showed the most potent phytotoxic activity in a tobacco leaf-wounding assay. Two novel phytotoxins were isolated from the liquid cultures of B. cinerea 2-16 by ethyl acetate extraction, flash silica gel column chromatography, silica gel column chromatography, Sephadex LH-20 column chromatography, preparative TLC and subsequently preparative HPLC. Their chemical structures were determined to be 3-O-acetyl botcinol and 3-O-acetyl botcinolide, respectively, by mass and NMR spectral analyses. These two phytotoxins caused leaf necrosis in a leaf-wounding bioassay, and significant electrolyte leakage from leaf tissues of tobacco. In the two bioassays tested, 3-O-acetyl botcinol exhibited stronger phytotoxic activity than 3-O-acetyl botcinolide. This is the first report on the production of both 3-O-acetyl botcinol and 3-O-acetyl botcinolide from B. cinerea.

• Research in Plant Disease
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• v.15 no.2
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• pp.120-126
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• 2009

In the course of study on the roles of phytotoxins in the pathogenicity of Botrytis cinerea, we isolated two novel phytotoxins. They were identified as 3-O-acetyl botcinol and 3-O-acetyl botcinolide. In this study, we investigated correlation between the two phytotoxins and the pathogenicity of B. cinerea. In liquid cultures, the two phytotoxins were not produced by three low pathogenic isolates out of 25 B. cinerea isolates. Among strong or moderate pathogenic isolates, some produced the two phytotoxins, but the others did not. On the other hand, the ethyl acetate extracts of fermentation broths of 10 out of 25 isolates showed phytotoxic activity against various plants tested in a whole plant assay. The phytotoxins were detected in all of the 10 phytotoxic ethyl acetate extracts. In planta, the two phytotoxins were detected in all of the plant tissues infected with strong pathogenic isolates. However, there was no correlation between the ability of B. cinerea isolates to produce the two phytotoxins and their pathogenicities. The two phytotoxins began to detect in tomato plant tissues infected with B. cinerea 2-16 at 3 days after inoculation, increased gradually till 4 days after inoculation, and then decreased. The above results suggest that 3-O-acetyl botcinol and 3-O-acetyl botcinolide are one of pathogenicity factors for B. cinerea, but not a primary determinant of its pathogenicity.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.98.2-99
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• 2002