Ergot alkaloids are indole-derived mycotoxins that are important in agriculture and medicine. Ergot alkaloids are produced by a few representatives of two distantly related fungal lineages, the Clavicipitaceae and the Trichocomaceae. Comparison of the ergot alkaloid gene clusters from these two lineages revealed differences in the relative positions and orientations of several genes. The question arose: is ergot alkaloid biosynthetic capability from a common origin? We used a molecular phylogenetic approach to gain insights into the evolution of ergot alkaloid biosynthesis. The 4-γ,γ-dimethylallyltryptophan synthase gene, dmaW, encodes the first step in the pathway. Amino acid sequences deduced from dmaW and homologs were submitted to phylogenetic analysis, and the results indicated that dmaW of Aspergillus fumigatus (mitosporic Trichocomaceae) has the same origin as corresponding genes from clavicipitaceous fungi. Relationships of authentic dmaW genes suggest that they originated from multiple gene duplications with subsequent losses of original or duplicate versions in some lineages.
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This project was supported by the National Research Initiative of the USDA Cooperative State Research, Education and Extension Service, grant number 2008-35318-04549.
This article is published with the approval of the Kentucky Agricultural Experiment Station as publication number 09-12-058, and with the approval of the Director of the WV Agricultural and Forestry Experiment Station as Scientific Article number 3037.
Liu, Miao; Panaccione, Daniel G.; and Schardl, Christopher L., "Phylogenetic Analyses Reveal Monophyletic Origin of the Ergot Alkaloid Gene dmaW in Fungi" (2009). Plant Pathology Faculty Publications. 77.