Sipha maydis sensitivity to defences of Lolium multiflorum and its endophytic fungus Epichloë occultans
Background Plants possess a sophisticated immune system to defend from herbivores. These defence responses are regulated by plant hormones including salicylic acid (SA) and jasmonic acid (JA). Sometimes, plant defences can be complemented by the presence of symbiotic microorganisms. A remarkable exa...
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PeerJ Inc.
2019-12-01
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| author | Daniel A. Bastías Maria Alejandra Martínez-Ghersa Jonathan A. Newman Stuart D. Card Wade J. Mace Pedro E. Gundel |
| author_facet | Daniel A. Bastías Maria Alejandra Martínez-Ghersa Jonathan A. Newman Stuart D. Card Wade J. Mace Pedro E. Gundel |
| author_sort | Daniel A. Bastías |
| collection | DOAJ |
| description | Background Plants possess a sophisticated immune system to defend from herbivores. These defence responses are regulated by plant hormones including salicylic acid (SA) and jasmonic acid (JA). Sometimes, plant defences can be complemented by the presence of symbiotic microorganisms. A remarkable example of this are grasses establishing symbiotic associations with Epichloë fungal endophytes. We studied the level of resistance provided by the grass’ defence hormones, and that provided by Epichloë fungal endophytes, against an introduced herbivore aphid. These fungi protect their hosts against herbivores by producing bioactive alkaloids. We hypothesized that either the presence of fungal endophytes or the induction of the plant salicylic acid (SA) defence pathway would enhance the level of resistance of the grass to the aphid. Methods Lolium multiflorum plants, with and without the fungal endophyte Epichloë occultans, were subjected to an exogenous application of SA followed by a challenge with the aphid, Sipha maydis. Results Our results indicate that neither the presence of E. occultans nor the induction of the plant’s SA pathway regulate S. maydis populations. However, endophyte-symbiotic plants may have been more tolerant to the aphid feeding because these plants produced more aboveground biomass. We suggest that this insect insensitivity could be explained by a combination between the ineffectiveness of the specific alkaloids produced by E. occultans in controlling S. maydis aphids and the capacity of this herbivore to deal with hormone-dependent defences of L. multiflorum. |
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| language | English |
| last_indexed | 2024-03-09T07:03:27Z |
| publishDate | 2019-12-01 |
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| spelling | doaj.art-b309eb08761a4a35aa56b7e9bf825bf52023-12-03T09:46:17ZengPeerJ Inc.PeerJ2167-83592019-12-017e825710.7717/peerj.8257Sipha maydis sensitivity to defences of Lolium multiflorum and its endophytic fungus Epichloë occultansDaniel A. Bastías0Maria Alejandra Martínez-Ghersa1Jonathan A. Newman2Stuart D. Card3Wade J. Mace4Pedro E. Gundel5IFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, ArgentinaIFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, ArgentinaDepartment of Biology, Wilfrid Laurier University, Waterloo, Ontario, CanadaForage Science, AgResearch Limited, Grasslands Research Centre, Palmerston North, New ZealandForage Science, AgResearch Limited, Grasslands Research Centre, Palmerston North, New ZealandIFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, ArgentinaBackground Plants possess a sophisticated immune system to defend from herbivores. These defence responses are regulated by plant hormones including salicylic acid (SA) and jasmonic acid (JA). Sometimes, plant defences can be complemented by the presence of symbiotic microorganisms. A remarkable example of this are grasses establishing symbiotic associations with Epichloë fungal endophytes. We studied the level of resistance provided by the grass’ defence hormones, and that provided by Epichloë fungal endophytes, against an introduced herbivore aphid. These fungi protect their hosts against herbivores by producing bioactive alkaloids. We hypothesized that either the presence of fungal endophytes or the induction of the plant salicylic acid (SA) defence pathway would enhance the level of resistance of the grass to the aphid. Methods Lolium multiflorum plants, with and without the fungal endophyte Epichloë occultans, were subjected to an exogenous application of SA followed by a challenge with the aphid, Sipha maydis. Results Our results indicate that neither the presence of E. occultans nor the induction of the plant’s SA pathway regulate S. maydis populations. However, endophyte-symbiotic plants may have been more tolerant to the aphid feeding because these plants produced more aboveground biomass. We suggest that this insect insensitivity could be explained by a combination between the ineffectiveness of the specific alkaloids produced by E. occultans in controlling S. maydis aphids and the capacity of this herbivore to deal with hormone-dependent defences of L. multiflorum.https://peerj.com/articles/8257.pdfAlkaloidsBeneficial microorganismsEndophyte symbiosisEpichloë fungalendophytesPlant defencesSalicylic acid |
| spellingShingle | Daniel A. Bastías Maria Alejandra Martínez-Ghersa Jonathan A. Newman Stuart D. Card Wade J. Mace Pedro E. Gundel Sipha maydis sensitivity to defences of Lolium multiflorum and its endophytic fungus Epichloë occultans PeerJ Alkaloids Beneficial microorganisms Endophyte symbiosis Epichloë fungalendophytes Plant defences Salicylic acid |
| title | Sipha maydis sensitivity to defences of Lolium multiflorum and its endophytic fungus Epichloë occultans |
| title_full | Sipha maydis sensitivity to defences of Lolium multiflorum and its endophytic fungus Epichloë occultans |
| title_fullStr | Sipha maydis sensitivity to defences of Lolium multiflorum and its endophytic fungus Epichloë occultans |
| title_full_unstemmed | Sipha maydis sensitivity to defences of Lolium multiflorum and its endophytic fungus Epichloë occultans |
| title_short | Sipha maydis sensitivity to defences of Lolium multiflorum and its endophytic fungus Epichloë occultans |
| title_sort | sipha maydis sensitivity to defences of lolium multiflorum and its endophytic fungus epichloe occultans |
| topic | Alkaloids Beneficial microorganisms Endophyte symbiosis Epichloë fungalendophytes Plant defences Salicylic acid |
| url | https://peerj.com/articles/8257.pdf |
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