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Bastías DA, Martínez-Ghersa MA, Newman JA, Card SD, Mace WJ, Gundel PE. Sipha maydis sensitivity to defences of Lolium multiflorum and its endophytic fungus Epichloë occultans. PeerJ 2019; 7:e8257. [PMID: 31976166 PMCID: PMC6966988 DOI: 10.7717/peerj.8257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 11/20/2019] [Indexed: 01/29/2023] Open
Abstract
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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Affiliation(s)
- Daniel A. Bastías
- IFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
- Forage Science, AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | | | - Jonathan A. Newman
- Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, Canada
| | - Stuart D. Card
- Forage Science, AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Wade J. Mace
- Forage Science, AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Pedro E. Gundel
- IFEVA, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Buenos Aires, Argentina
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do Prado Ribeiro L, Klock ALS, Filho JAW, Tramontin MA, Trapp MA, Mithöfer A, Nansen C. Hyperspectral imaging to characterize plant-plant communication in response to insect herbivory. Plant Methods 2018; 14:54. [PMID: 29988987 PMCID: PMC6034322 DOI: 10.1186/s13007-018-0322-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 06/29/2018] [Indexed: 05/20/2023]
Abstract
BACKGROUND In studies of plant stress signaling, a major challenge is the lack of non-invasive methods to detect physiological plant responses and to characterize plant-plant communication over time and space. RESULTS We acquired time series of phytocompound and hyperspectral imaging data from maize plants from the following treatments: (1) individual non-infested plants, (2) individual plants experimentally subjected to herbivory by green belly stink bug (no visible symptoms of insect herbivory), (3) one plant subjected to insect herbivory and one control plant in a separate pot but inside the same cage, and (4) one plant subjected to insect herbivory and one control plant together in the same pot. Individual phytocompounds (except indole-3acetic acid) or spectral bands were not reliable indicators of neither insect herbivory nor plant-plant communication. However, using a linear discrimination classification method based on combinations of either phytocompounds or spectral bands, we found clear evidence of maize plant responses. CONCLUSIONS We have provided initial evidence of how hyperspectral imaging may be considered a powerful non-invasive method to increase our current understanding of both direct plant responses to biotic stressors but also to the multiple ways plant communities are able to communicate. We are unaware of any published studies, in which comprehensive phytocompound data have been shown to correlate with leaf reflectance. In addition, we are unaware of published studies, in which plant-plant communication was studied based on leaf reflectance.
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Affiliation(s)
- Leandro do Prado Ribeiro
- Research Center for Family Agriculture, Research and Rural, Extension Company of Santa Catarina, Chapecó, Santa Catarina Brazil
| | - Adriana Lídia Santana Klock
- Research Center for Family Agriculture, Research and Rural, Extension Company of Santa Catarina, Chapecó, Santa Catarina Brazil
| | - João Américo Wordell Filho
- Research Center for Family Agriculture, Research and Rural, Extension Company of Santa Catarina, Chapecó, Santa Catarina Brazil
| | | | - Marília Almeida Trapp
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Axel Mithöfer
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Christian Nansen
- Department of Entomology and Nematology, University of California, UC Davis Briggs Hall, Room 367, Davis, CA 95616 USA
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, 198 Shiqiao Road, Hangzhou, 310021 China
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Godinho DP, Janssen A, Dias T, Cruz C, Magalhães S. Down-regulation of plant defence in a resident spider mite species and its effect upon con- and heterospecifics. Oecologia 2015; 180:161-7. [PMID: 26369779 DOI: 10.1007/s00442-015-3434-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 08/06/2015] [Indexed: 01/25/2023]
Abstract
Herbivorous spider mites occurring on tomato plants (Solanum lycopersicum L.) cope with plant defences in various manners: the invasive Tetranychus evansi reduces defences below constitutive levels, whereas several strains of T. urticae induce such defences and others suppress them. In the Mediterranean region, these two species co-occur on tomato plants with T. ludeni, another closely related spider mite species. Unravelling how this third mite species affects plant defences is thus fundamental to understanding the outcome of herbivore interactions in this system. To test the effect of T. ludeni on tomato plant defences, we measured (1) the activity of proteinase inhibitors, indicating the induction of plant defences, in those plants, and (2) mite performance on plants previously infested with each mite species. We show that the performance of T. evansi and T. ludeni on plants previously infested with T. ludeni or T. evansi was better than on clean plants, indicating that these two mite species down-regulate plant defences. We also show that plants attacked by these mite species had lower activity of proteinase inhibitors than clean plants, whereas herbivory by T. urticae increased the activity of these proteins and resulted in reduced spider mite performance. This study thus shows that the property of down-regulation of plant defences below constitutive levels also occurs in T. ludeni.
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Affiliation(s)
- Diogo P Godinho
- cE3c, Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
| | - Arne Janssen
- Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands
| | - Teresa Dias
- cE3c, Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
| | - Cristina Cruz
- cE3c, Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
| | - Sara Magalhães
- cE3c, Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal.
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Vourc'h G, Martin JL, Duncan P, Escarré J, Clausen TP. Defensive adaptations of Thuja plicata to ungulate browsing: a comparative study between mainland and island populations. Oecologia 2001; 126:84-93. [PMID: 28547441 DOI: 10.1007/s004420000491] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/1999] [Accepted: 07/17/2000] [Indexed: 11/26/2022]
Abstract
Forests on the Haida Gwaii (HG) archipelago (British Columbia, Canada) evolved for about 10,000 years in the absence of large-mammal browsing. The introduction of black-tailed deer (Odocoileus hemionus sitkensis) from the mainland prior to 1901 provides an opportunity to evaluate changes in the adaptive defensive responses of plants to herbivory. We compared (1) food choice by deer and (2) chemical defence (terpene concentrations) between HG and mainland red cedars (Thuja plicata) using (1) nursery-grown seedlings never exposed to deer, (2) branches from trees that grew before the introduction of deer ("old trees") and (3) saplings exposed to deer herbivory on the mainland and on HG. We used the first two plant categories to test the hypothesis that plants that evolve under low herbivory levels have lower anti-herbivore defences. We used saplings to study the consequences of the dramatic increase in browsing on HG. During food experiments, deer preferred HG seedlings and old tree branches compared to those from the mainland. Total monoterpene concentrations were much higher than diterpene concentrations in all plant categories. Within plant categories, multivariate analysis showed that terpene profiles differed significantly between HG and mainland red cedars: HG seedlings and old trees had lower monoterpene levels. These results suggest that some monoterpenes may be determinants of deer food choice and that the defences of HG plants are less effective than those of mainland plants. The deer used branches from HG and mainland saplings indiscriminately. However, terpene profiles differed significantly between HG and mainland saplings, with multivariate analysis suggesting a higher defensive response in browsed HG saplings. Monoterpene profiles were different in lightly and heavily browsed saplings from HG, suggesting that under the current browsing regime, individuals with the greatest constitutive defences, or with greatest potential for induced defences, grow better and are selected on HG.
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Affiliation(s)
- Gwenaël Vourc'h
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS UPR 9056, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Jean-Louis Martin
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS UPR 9056, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Patrick Duncan
- Centre d'Etudes Biologiques de Chizé, CNRS UPR 1934, 79360, Beauvoir-sur-Niort, France
| | - José Escarré
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS UPR 9056, 1919 route de Mende, 34293, Montpellier Cedex 5, France
| | - Thomas P Clausen
- Department of Chemistry, University of Alaska Fairbanks, 99775-6160, Fairbanks, AK, USA
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