Mitochondrial Signs and Subcellular Imaging Imply the Antifungal Mechanism of Carabrone against Gaeumannomyces graminis var. tritici

Mitochondrial Signs and Subcellular Imaging Imply the Antifungal Mechanism of Carabrone against Gaeumannomyces graminis var. tritici

Carabrone, a botanical bicyclic sesquiterpenic lactone, has broad-spectrum antifungal activities, and is particularly efficient against the devastating phytopathogen Gaeumannomyces graminis var.tritici (Ggt). The antifungal mechanism of carabrone against Ggt, however, remains unclear. The main objec...

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Bibliographic Details
Published in:Journal of agricultural and food chemistry 2017-12
Main Authors: Wang, Lanying, Zhang, Yunfei, Wang, Delong, Wang, Mei, Wang, Yong, Feng, Juntao
Format: Article
Language:eng
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Summary:Carabrone, a botanical bicyclic sesquiterpenic lactone, has broad-spectrum antifungal activities, and is particularly efficient against the devastating phytopathogen Gaeumannomyces graminis var.tritici (Ggt). The antifungal mechanism of carabrone against Ggt, however, remains unclear. The main objective of this study was to investigate the subcellular localization of carabrone in Ggt to make a better understanding of the mechanism of action. When Ggt was exposed to carabrone (EC value, 28.45 μg/mL) for 7 days, the decline of mitochondrial concentration, together with some obvious alternations in the mitochondrial structure including hazy outline, medullary transition, excess accumulation of unclear settlings, and vacuolar degeneration were observed, indicating that carbrone may act on the mitochondria directly. A fluorescent conjugate (TTY) was thus designed and synthesized as a surrogate of carabrone, which possessed comparable antifungal activity against Ggt (EC , 33.68 μg/mL). Meanwhile, polyclonal antibody specific to carabrone with a high titer (256,000) was also prepared by immunizing mice. Subsequently, two imaging techniques, fluorescent conjugate (FC) and immunofluorescence (IF), were applied to determine the subcellular localization of carabrone. Both FC and IF fluorescent signals demonstrated its mitochondrial localization with a Pearson's coefficient of 0.83 for FC, and 0.86 for IF. These results imply that carabrone exerts its antifungal activity against Ggt by interference with mitochondrial functions.
ISSN:1520-5118