The epichloid fungi - comprising sexual . Epichloë species and asexual . Neotyphodium species - are symbionts of cool-season grasses (subfamily Poöideae), mostly vertically transmissible (seedborne), and well known for production of anti-herbivore alkaloids. Four classes of alkaloids are known to be produced by epichloae: lolines (saturated aminopyrrolizidines), indole-diterpenes, ergot alkaloids, and peramine. There is a wide range of chemotypic diversity among and even within epichloid species. At the molecular level, this diversity may in part reflect the telomeric association of two of the four alkaloid biosynthesis gene clusters. Ecologically, the chemotypic diversity within species may reflect frequency-dependent selection for the alkaloids, which provide defences against insects and, in some cases, vertebrates, but can be expensive to produce. Interspecific hybridization, common among asexual epichloae, can pyramid the alkaloid biosynthesis genes. Compared to sexual epichloae, many asexual epichloae produce high levels of alkaloids - particularly lolines - suggesting that strict vertical transmission selects for enhanced capability of host protection.
|Number of pages||14|
|State||Published - Jun 2012|
Bibliographical noteFunding Information:
We thank Daniel G. Panaccione (West Virginia University), Brian Tapper and Geoff Lane (AgResearch, New Zealand) for unpublished results of alkaloid analysis, and Walter Hollin and Shipra Mittal for technical assistance. Alkaloid data and genetic screening were supported by U.S. Department of Agriculture grants 2008-35318-04549 and 2009-111-31030 , and The Samuel Roberts Noble Foundation . Genomic DNA and transcriptome sequences were generated with support from National Science Foundation grants EF-0523661 and EPS-0814194 , and U.S. Department of Agriculture grants 2005-35319-16141 and 2008-34457-19176 .
- Biosynthesis genes
- Fungus species
- Vertical transmission
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Ecological Modeling
- Plant Science