Modulation of Ergot Alkaloids in a Grass–Endophyte Symbiosis by Alteration of mRNA Concentrations of an Ergot Alkaloid Synthesis Gene

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• 作者：Prashanthi Mulinti ; Simona Florea ; Christopher L. Schardl ; Daniel G. Panaccione
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2016
• 出版时间：June 22, 2016
• 年：2016
• 卷：64
• 期：24
• 页码：4982-4989
• 全文大小：375K
• 年卷期：0
• ISSN：1520-5118

文摘

The profile of ergot alkaloids in perennial ryegrass (Lolium perenne) containing the endophytic fungus Epichloë typhina × festucae includes high concentrations of the early pathway metabolites ergotryptamine and chanoclavine-I in addition to the pathway end-product ergovaline. Because these alkaloids differ in activity, we investigated strategies to alter their relative concentrations. An RNAi-based approach reduced the concentration of mRNA from the gene easA, which encodes an enzyme required for a ring closure that separates ergotryptamine and chanoclavine-I from ergovaline. Lower easA mRNA concentrations correlated with lower concentrations of ergovaline and higher concentrations of ergotryptamine and chanoclavine-I. Overexpression of easA led to higher concentrations of ergovaline in leaf blades but not in pseudostems; concentrations of the early pathway metabolites were not altered in overexpression strains. The data indicate that altering the concentration of mRNA from a single gene can change alkaloid flux, but the magnitude of the change was limited and variable.