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Bubica Bustos LM, Ueno AC, Biganzoli F, Card SD, Mace WJ, Martínez-Ghersa MA, Gundel PE. Can Aphid Herbivory Induce Intergenerational Effects of Endophyte-conferred Resistance in Grasses? J Chem Ecol 2022; 48:867-881. [PMID: 36372818 DOI: 10.1007/s10886-022-01390-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/20/2022] [Accepted: 10/23/2022] [Indexed: 11/15/2022]
Abstract
Plants have evolved mechanisms to survive herbivory. One such mechanism is the induction of defences upon attack that can operate intergenerationally. Cool-season grasses (sub-family Pooideae) obtain defences via symbiosis with vertically transmitted fungal endophytes (genus Epichloë) and can also show inducible responses. However, it is unknown whether these herbivore-induced responses can have intergenerational effects. We hypothesized that herbivory by aphids on maternal plants induces the intergenerational accumulation of endophyte-derived defensive alkaloids and resistance intensification in the progeny. We subjected mother plants symbiotic or not with Epichloë occultans, a species known for its production of anti-insect alkaloids known as lolines, to the aphid Rhopalosiphum padi. Then, we evaluated the progeny of these plants in terms of loline alkaloid concentration, resistance level (through herbivore performance), and shoot biomass. Herbivory on mother plants did not increase the concentration of lolines in seeds but it tended to affect loline concentration in progeny plants. There was an overall herbivore-induced intergenerational effect increasing the endophyte-conferred defence and resistance. Symbiotic plants were more resistant to aphids and had higher shoot biomass than their non-symbiotic counterparts. Since maternal herbivory did not affect the loline concentrations in seeds, the greater resistance of the progeny could have resulted from an inherited mechanism of epigenetic regulation. It would be interesting to elucidate the origin of this regulation since it could come from the host or the fungal symbiont. Thus, endophyte-driven differential fitness between symbiotic and non-symbiotic plants might be higher as generations pass on in presence of herbivores.
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Affiliation(s)
| | - Andrea C Ueno
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Campus Lircay, Talca, Chile
| | - Fernando Biganzoli
- Departamento de Métodos Cuantitativos y Sistemas de Información, Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Stuart D Card
- Resilient Agriculture, Grasslands Research Centre, AgResearch Limited, Palmerston North, New Zealand
| | - Wade J Mace
- Resilient Agriculture, Grasslands Research Centre, AgResearch Limited, Palmerston North, New Zealand
| | | | - Pedro E Gundel
- IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina.
- Centro de Ecología Integrativa, Instituto de Ciencias Biológicas, Universidad de Talca, Campus Lircay, Talca, Chile.
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Grupstra CGB, Lemoine NP, Cook C, Correa AMS. Thank you for biting: dispersal of beneficial microbiota through 'antagonistic' interactions. Trends Microbiol 2022; 30:930-939. [PMID: 35393166 DOI: 10.1016/j.tim.2022.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 12/23/2022]
Abstract
Multicellular organisms harbor populations of microbial symbionts; some of these symbionts can be dispersed through the feeding activities of consumers. Studies of consumer-mediated microbiota dispersal generally focus on pathogenic microorganisms; the dispersal of beneficial microorganisms has received less attention, especially in the context of 'antagonistic' trophic interactions (e.g., herbivory, parasitism, predation). Yet, this 'trophic transmission' of beneficial symbionts has significant implications for microbiota assembly and resource species (e.g., prey) health. For example, trophic transmission of microorganisms could assist with environmental acclimatization and help resource species to suppress other consumers or competitors. Here, we highlight model systems and approaches that have revealed these potential 'silver-linings' of antagonism as well as opportunities and challenges for future research.
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Affiliation(s)
- C G B Grupstra
- BioSciences Department, Rice University, Houston, TX 77098, USA.
| | - N P Lemoine
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA; Department of Zoology, Milwaukee Public Museum, Milwaukee, WI 53233, USA
| | - C Cook
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53233, USA
| | - A M S Correa
- BioSciences Department, Rice University, Houston, TX 77098, USA
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Bastías DA, Gianoli E, Gundel PE. Fungal endophytes can eliminate the plant growth-defence trade-off. THE NEW PHYTOLOGIST 2021; 230:2105-2113. [PMID: 33690884 DOI: 10.1111/nph.17335] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/08/2021] [Indexed: 05/27/2023]
Abstract
A trade-off between growth and defence functions is commonly observed in plants. We propose that the association of plants with Epichloë fungal endophytes may eliminate this trade-off. This would be a consequence of the double role of these endophytes in host plants: the stimulation of plant growth hormones (e.g. gibberellins) and the fungal production of antiherbivore alkaloids. We put forward a model that integrates this dual effect of endophytes on plant growth and defence and test its predictions by means of meta-analysis of published literature. Our results support the notion that the enhanced plant resistance promoted by endophytes does not compromise plant growth. The limits and ecological benefits of this endophyte-mediated lack of plant growth-defence trade-off are discussed.
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Affiliation(s)
- Daniel A Bastías
- Resilient Agriculture Innovation Centre of Excellence, AgResearch Limited, Grasslands Research Centre, Palmerston North, New Zealand
| | - Ernesto Gianoli
- Departamento de Biología, Universidad de La Serena, Casilla 554, La Serena, Chile
- Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción, Chile
| | - Pedro E Gundel
- Facultad de Agronomía, IFEVA, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
- Laboratorio de Biología Vegetal, Instituto de Ciencias Biológicas, Universidad de Talca, Campus Lircay, Talca, Chile
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Aghdam SA, Brown AMV. Deep learning approaches for natural product discovery from plant endophytic microbiomes. ENVIRONMENTAL MICROBIOME 2021; 16:6. [PMID: 33758794 PMCID: PMC7972023 DOI: 10.1186/s40793-021-00375-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/21/2021] [Indexed: 05/10/2023]
Abstract
Plant microbiomes are not only diverse, but also appear to host a vast pool of secondary metabolites holding great promise for bioactive natural products and drug discovery. Yet, most microbes within plants appear to be uncultivable, and for those that can be cultivated, their metabolic potential lies largely hidden through regulatory silencing of biosynthetic genes. The recent explosion of powerful interdisciplinary approaches, including multi-omics methods to address multi-trophic interactions and artificial intelligence-based computational approaches to infer distribution of function, together present a paradigm shift in high-throughput approaches to natural product discovery from plant-associated microbes. Arguably, the key to characterizing and harnessing this biochemical capacity depends on a novel, systematic approach to characterize the triggers that turn on secondary metabolite biosynthesis through molecular or genetic signals from the host plant, members of the rich 'in planta' community, or from the environment. This review explores breakthrough approaches for natural product discovery from plant microbiomes, emphasizing the promise of deep learning as a tool for endophyte bioprospecting, endophyte biochemical novelty prediction, and endophyte regulatory control. It concludes with a proposed pipeline to harness global databases (genomic, metabolomic, regulomic, and chemical) to uncover and unsilence desirable natural products. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1186/s40793-021-00375-0.
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Affiliation(s)
- Shiva Abdollahi Aghdam
- Department of Biological Sciences, Texas Tech University, 2901 Main St, Lubbock, TX 79409 USA
| | - Amanda May Vivian Brown
- Department of Biological Sciences, Texas Tech University, 2901 Main St, Lubbock, TX 79409 USA
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Vikuk V, Fuchs B, Krischke M, Mueller MJ, Rueb S, Krauss J. Alkaloid Concentrations of Lolium perenne Infected with Epichloë festucae var. lolii with Different Detection Methods-A Re-Evaluation of Intoxication Risk in Germany? J Fungi (Basel) 2020; 6:jof6030177. [PMID: 32961967 PMCID: PMC7558822 DOI: 10.3390/jof6030177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/09/2020] [Accepted: 09/15/2020] [Indexed: 11/29/2022] Open
Abstract
Mycotoxins in agriculturally used plants can cause intoxication in animals and can lead to severe financial losses for farmers. The endophytic fungus Epichloë festucae var. lolii living symbiotically within the cool season grass species Lolium perenne can produce vertebrate and invertebrate toxic alkaloids. Hence, an exact quantitation of alkaloid concentrations is essential to determine intoxication risk for animals. Many studies use different methods to detect alkaloid concentrations, which complicates the comparability. In this study, we showed that alkaloid concentrations of individual plants exceeded toxicity thresholds on real world grasslands in Germany, but not on the population level. Alkaloid concentrations on five German grasslands with high alkaloid levels peaked in summer but were also below toxicity thresholds on population level. Furthermore, we showed that alkaloid concentrations follow the same seasonal trend, regardless of whether plant fresh or dry weight was used, in the field and in a common garden study. However, alkaloid concentrations were around three times higher when detected with dry weight. Finally, we showed that alkaloid concentrations can additionally be biased to different alkaloid detection methods. We highlight that toxicity risks should be analyzed using plant dry weight, but concentration trends of fresh weight are reliable.
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Affiliation(s)
- Veronika Vikuk
- Department of Animal Ecology and Tropical Biology, University of Würzburg, 97074 Würzburg, Germany; (S.R.); (J.K.)
- Correspondence:
| | - Benjamin Fuchs
- Biodiversity Unit, University of Turku, 20014 Turku, Finland;
| | - Markus Krischke
- Department of Pharmaceutical Biology, Metabolomics Core Unit, University of Würzburg, 97074 Würzburg, Germany; (M.K.); (M.J.M.)
| | - Martin J. Mueller
- Department of Pharmaceutical Biology, Metabolomics Core Unit, University of Würzburg, 97074 Würzburg, Germany; (M.K.); (M.J.M.)
| | - Selina Rueb
- Department of Animal Ecology and Tropical Biology, University of Würzburg, 97074 Würzburg, Germany; (S.R.); (J.K.)
| | - Jochen Krauss
- Department of Animal Ecology and Tropical Biology, University of Würzburg, 97074 Würzburg, Germany; (S.R.); (J.K.)
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Maternal Exposure to Ozone Modulates the Endophyte-Conferred Resistance to Aphids in Lolium multiflorum Plants. INSECTS 2020; 11:insects11090548. [PMID: 32824905 PMCID: PMC7564161 DOI: 10.3390/insects11090548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/06/2020] [Accepted: 08/11/2020] [Indexed: 01/29/2023]
Abstract
Plants are challenged by biotic and abiotic stress factors and the incidence of one can increase or decrease resistance to another. These relations can also occur transgenerationally. For instance, progeny plants whose mothers experienced herbivory can be more resistant to herbivores. Certain fungal endophytes that are vertically transmitted endow plants with alkaloids and resistance to herbivores. However, endophyte-symbiotic plants exposed to the oxidative agent ozone became susceptible to aphids. Here, we explored whether this effect persists transgenerationally. We exposed Lolium multiflorum plants with and without fungal endophyte Epichloë occultans to ozone (120 or 0 ppb), and then, challenged the progeny with aphids (Rhopalosiphum padi). The endophyte was the main factor determining the resistance to aphids, but its importance diminished in plants with ozone history. This negative ozone effect on the endophyte-mediated resistance was apparent on aphid individual weights. Phenolic compounds in seeds were increased by the symbiosis and diminished by the ozone. The endophyte effect on phenolics vanished in progeny plants while the negative ozone effect persisted. Independently of ozone, the symbiosis increased the plant biomass (≈24%). Although ozone can diminish the importance of endophyte symbiosis for plant resistance to herbivores, it would be compensated by host growth stimulation.
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