A fungal endophyte induces transcription of genes encoding a redundant fungicide pathway in its host plant

BMC Plant Biology

Research Article

Christopher P Trobacher¹  John S Greenwood¹  Manish N Raizada²  Sameh SM Soliman³  Rong Tsao⁴ 

[1] Department of Molecular and Cellular Biology, University of Guelph, N1G 2W1, Guelph, ON, Canada;Department of Plant Agriculture, University of Guelph, N1G 2W1, Guelph, ON, Canada;Department of Plant Agriculture, University of Guelph, N1G 2W1, Guelph, ON, Canada;Faculty of Pharmacy, Zagazig University, Zagazig, Egypt;The Guelph Food Research Centre, Agriculture and Agri-Food Canada, N1G 5C9, Guelph, ON, Canada;

关键词: Taxus;    Paraconiothyrium;    Fungus;    Endophyte;    Taxol;    Biosynthesis;    Fungicide;    DXR;    Taxadiene synthase;   

DOI  :  10.1186/1471-2229-13-93

 received in 2013-02-01, accepted in 2013-06-11,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundTaxol is an anti-cancer drug harvested from Taxus trees, proposed ecologically to act as a fungicide. Taxus is host to fungal endophytes, defined as organisms that inhabit plants without causing disease. The Taxus endophytes have been shown to synthesize Taxol in vitro, providing Taxus with a second potential biosynthetic route for this protective metabolite. Taxol levels in plants vary 125-fold between individual trees, but the underlying reason has remained unknown.ResultsComparing Taxus trees or branches within a tree, correlations were observed between Taxol content, and quantity of its resident Taxol-producing endophyte, Paraconiothyrium SSM001. Depletion of fungal endophyte in planta by fungicide reduced plant Taxol accumulation. Fungicide treatment of intact plants caused concomitant decreases in transcript and/or protein levels corresponding to two critical genes required for plant Taxol biosynthesis. Taxol showed fungicidal activity against fungal pathogens of conifer wood, the natural habitat of the Taxol-producing endophyte. Consistent with other Taxol-producing endophytes, SSM001 was resistant to Taxol.ConclusionsThese results suggest that the variation in Taxol content between intact Taxus plants and/or tissues is at least in part caused by varying degrees of transcriptional elicitation of plant Taxol biosynthetic genes by its Taxol-producing endophyte. As Taxol is a fungicide, and the endophyte is resistant to Taxol, we discuss how this endophyte strategy may be to prevent colonization by its fungal competitors but at minimal metabolic cost to itself.

【 授权许可】

Unknown   
© Soliman et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.