Genetic Manipulation of the Ergot Alkaloid Pathway in <i>Epichloë festucae</i> var. <i>lolii</i> and Its Effect on Black Beetle Feeding Deterrence
<i>Epichloë</i> endophytes are filamentous fungi (family Clavicipitaceae) that live in symbiotic associations with grasses in the sub family Poöideae. In New Zealand, <i>E. festucae</i> var. <i>lolii</i> confers significant resistance to perennial ryegrass (<i&...
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MDPI AG
2021-01-01
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| Series: | Toxins |
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| Online Access: | https://www.mdpi.com/2072-6651/13/2/76 |
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| author | Debbie Hudson Wade Mace Alison Popay Joanne Jensen Catherine McKenzie Catherine Cameron Richard Johnson |
| author_facet | Debbie Hudson Wade Mace Alison Popay Joanne Jensen Catherine McKenzie Catherine Cameron Richard Johnson |
| author_sort | Debbie Hudson |
| collection | DOAJ |
| description | <i>Epichloë</i> endophytes are filamentous fungi (family Clavicipitaceae) that live in symbiotic associations with grasses in the sub family Poöideae. In New Zealand, <i>E. festucae</i> var. <i>lolii</i> confers significant resistance to perennial ryegrass (<i>Lolium perenne</i>) against insect and animal herbivory and is an essential component of pastoral agriculture, where ryegrass is a major forage species. The fungus produces in planta a range of bioactive secondary metabolites, including ergovaline, which has demonstrated bioactivity against the important pasture pest black beetle, but can also cause mammalian toxicosis. We genetically modified <i>E. festucae</i> var. <i>lolii</i> strain AR5 to eliminate key enzymatic steps in the ergovaline pathway to determine if intermediate ergot alkaloid compounds can still provide insecticidal benefits in the absence of the toxic end product ergovaline. Four genes (<i>dmaW</i>, <i>easG</i>, <i>cloA</i>, and <i>lpsB</i>) spanning the pathway were deleted and each deletion mutant was inoculated into five different plant genotypes of perennial ryegrass, which were later harvested for a full chemical analysis of the ergot alkaloid compounds produced. These associations were also used in a black beetle feeding deterrence study. Deterrence was seen with just chanoclavine present, but was cumulative as more intermediate compounds in the pathway were made available. Ergovaline was not detected in any of the deletion associations, indicating that bioactivity towards black beetle can be obtained in the absence of this mammalian toxin. |
| first_indexed | 2024-03-09T04:07:35Z |
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| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-09T04:07:35Z |
| publishDate | 2021-01-01 |
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| series | Toxins |
| spelling | doaj.art-3ea8af5696944adc8c4c133477fd47f02023-12-03T14:04:12ZengMDPI AGToxins2072-66512021-01-011327610.3390/toxins13020076Genetic Manipulation of the Ergot Alkaloid Pathway in <i>Epichloë festucae</i> var. <i>lolii</i> and Its Effect on Black Beetle Feeding DeterrenceDebbie Hudson0Wade Mace1Alison Popay2Joanne Jensen3Catherine McKenzie4Catherine Cameron5Richard Johnson6AgResearch Limited, Grasslands Research Centre, Private Bag 11008, Palmerston North, New ZealandAgResearch Limited, Grasslands Research Centre, Private Bag 11008, Palmerston North, New ZealandAgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, New ZealandAgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, New ZealandAgResearch Limited, Grasslands Research Centre, Private Bag 11008, Palmerston North, New ZealandAgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, New ZealandAgResearch Limited, Grasslands Research Centre, Private Bag 11008, Palmerston North, New Zealand<i>Epichloë</i> endophytes are filamentous fungi (family Clavicipitaceae) that live in symbiotic associations with grasses in the sub family Poöideae. In New Zealand, <i>E. festucae</i> var. <i>lolii</i> confers significant resistance to perennial ryegrass (<i>Lolium perenne</i>) against insect and animal herbivory and is an essential component of pastoral agriculture, where ryegrass is a major forage species. The fungus produces in planta a range of bioactive secondary metabolites, including ergovaline, which has demonstrated bioactivity against the important pasture pest black beetle, but can also cause mammalian toxicosis. We genetically modified <i>E. festucae</i> var. <i>lolii</i> strain AR5 to eliminate key enzymatic steps in the ergovaline pathway to determine if intermediate ergot alkaloid compounds can still provide insecticidal benefits in the absence of the toxic end product ergovaline. Four genes (<i>dmaW</i>, <i>easG</i>, <i>cloA</i>, and <i>lpsB</i>) spanning the pathway were deleted and each deletion mutant was inoculated into five different plant genotypes of perennial ryegrass, which were later harvested for a full chemical analysis of the ergot alkaloid compounds produced. These associations were also used in a black beetle feeding deterrence study. Deterrence was seen with just chanoclavine present, but was cumulative as more intermediate compounds in the pathway were made available. Ergovaline was not detected in any of the deletion associations, indicating that bioactivity towards black beetle can be obtained in the absence of this mammalian toxin.https://www.mdpi.com/2072-6651/13/2/76<i>Epichloë</i>ergot alkaloidergovalineblack beetle<i>Heteronychus arator</i>perennial ryegrass |
| spellingShingle | Debbie Hudson Wade Mace Alison Popay Joanne Jensen Catherine McKenzie Catherine Cameron Richard Johnson Genetic Manipulation of the Ergot Alkaloid Pathway in <i>Epichloë festucae</i> var. <i>lolii</i> and Its Effect on Black Beetle Feeding Deterrence Toxins <i>Epichloë</i> ergot alkaloid ergovaline black beetle <i>Heteronychus arator</i> perennial ryegrass |
| title | Genetic Manipulation of the Ergot Alkaloid Pathway in <i>Epichloë festucae</i> var. <i>lolii</i> and Its Effect on Black Beetle Feeding Deterrence |
| title_full | Genetic Manipulation of the Ergot Alkaloid Pathway in <i>Epichloë festucae</i> var. <i>lolii</i> and Its Effect on Black Beetle Feeding Deterrence |
| title_fullStr | Genetic Manipulation of the Ergot Alkaloid Pathway in <i>Epichloë festucae</i> var. <i>lolii</i> and Its Effect on Black Beetle Feeding Deterrence |
| title_full_unstemmed | Genetic Manipulation of the Ergot Alkaloid Pathway in <i>Epichloë festucae</i> var. <i>lolii</i> and Its Effect on Black Beetle Feeding Deterrence |
| title_short | Genetic Manipulation of the Ergot Alkaloid Pathway in <i>Epichloë festucae</i> var. <i>lolii</i> and Its Effect on Black Beetle Feeding Deterrence |
| title_sort | genetic manipulation of the ergot alkaloid pathway in i epichloe festucae i var i lolii i and its effect on black beetle feeding deterrence |
| topic | <i>Epichloë</i> ergot alkaloid ergovaline black beetle <i>Heteronychus arator</i> perennial ryegrass |
| url | https://www.mdpi.com/2072-6651/13/2/76 |
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