Indole-diterpene biosynthetic capability of epichloë endophytes as predicted by ltm gene analysis
In: Applied and environmental microbiology, Jg. 75 (2009-02-03), Heft 7
Online
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Zugriff:
Bioprotective alkaloids produced byEpichloëand closely related asexualNeotyphodiumfungal endophytes protect their grass hosts from insect and mammalian herbivory. One class of these compounds, known for antimammalian toxicity, is the indole-diterpenes. TheLTMlocus ofNeotyphodium lolii(Lp19) andEpichloë festuce(Fl1), required for the biosynthesis of the indole-diterpene lolitrem, consists of 10ltmgenes. We have used PCR and Southern analysis to screen a broad taxonomic range of 44 endophyte isolates to determine why indole-diterpenes are present in so few endophyte-grass associations in comparison to that of the other bioprotective alkaloids, which are more widespread among the endophtyes. All 10ltmgenes were present in only three epichloë endophytes. A predominance of the asexualNeotyphodiumspp. examined contained 8 of the 10ltmgenes, with only oneN. loliicontaining the entireLTMlocus and the ability to produce lolitrems. Liquid chromatography-tandem mass spectrometry profiles of indole-diterpenes from a subset of endophyte-infected perennial ryegrass showed that endophytes that contained functional genes present inltmclusters 1 and 2 were capable of producing simple indole-diterpenes such as paspaline, 13-desoxypaxilline, and terpendoles, compounds predicted to be precursors of lolitrem B. Analysis of toxin biosynthesis genes by PCR now enables a diagnostic method to screen endophytes for both beneficial and detrimental alkaloids and can be used as a resource for screening isolates required for forage improvement.
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Indole-diterpene biosynthetic capability of epichloë endophytes as predicted by ltm gene analysis
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Autor/in / Beteiligte Person: | May, Kimberley J. ; Schardl, Christopher L. ; Young, Carolyn A. ; Moon, Christina D. ; Scott, Barry ; Tapper, B. A. |
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Zeitschrift: | Applied and environmental microbiology, Jg. 75 (2009-02-03), Heft 7 |
Veröffentlichung: | 2009 |
Medientyp: | unknown |
ISSN: | 1098-5336 (print) |
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