Characterisation of Chemical Signalling from Beneficial Trichoderma spp.
Lead Research Organisation:
University of Exeter
Department Name: Biosciences
Abstract
Trichoderma species are ubiquitous soil saprotrophs utilized in agriculture for their biocontrol activities. Some strains additionally possess the ability to activate induced systemic resistance (ISR) to a broad range of pathogens. Other strains have been shown to stimulate plant growth through the production of plant-growth-promoting (PGP) compounds, although both traits are rarely found together. This project focuses upon a novel, free-living, strain of T. hamatum, which exhibits biocontrol and plant growth promotion (PGP) capabilities in both monocots and dicots, controls plant diseases caused by pre- and post-emergence pathogens, can induce systemic resistance and modify root architecture, even in species where no increase in canopy development is evident (e.g. maize & wheat). As with other biocontrol/PGP solutions, field application presents many challenges. Complex cross-talk occurs during beneficial rhizosphere interactions and is influenced by the climate, soil type, time of year and host genotype, e.g. in tomato-T. atroviride and T. harzianum interactions. Therefore, there is significant added value in studies that seek to understand and exploit the chemical ecology that underpins beneficial traits conferred by Trichoderma in the rhizosphere.
This project will use an interdisciplinary approach to elucidate the novel bioactive chemistry produced by T. hamatum that contributes to these agronomically important traits. Bioassay-guided fractionation (using advanced chromatographic/spectroscopic analysis i.e. MS and NMR) will be used to identify bioactive natural products from microcosm extracts of Trichoderma hamatum that provide protection of lettuce (Lactuca sativa) or brassicas against the soil pathogen Sclerotinia sclerotorium (Ss). In-soil capture of the identified chemical signals, from Trichoderma isolates and the host plants will be carried out by the insertion of reverse-phase coated fibres into Trichoderma-amended soil environment of plants, in the presence or absence of Ss, and then elution/analysis of the captured compounds. This technique will shed light on the identity of the causal metabolites involved in potential enhancement of root defence against herbivores eg. clover root weevils, Sitona lepidus.
This interdisciplinary project will provide training in aspects of natural product chemistry, chemical ecology and microbiology. It will be based in Rothamsted in the lab of MB, where training in biological chemistry methods including bioassay-guided fractionation and analysis will be provided. The first year rotation will be based in MG's lab in Exeter. The candidate will train in generating microcosms, preparation of extracts with antibiotic activity from wild-type and mutant T. hamatum and undertake biological assays to evaluate Ss (or other pathogen) performance in a background of extracts, fractions and compounds.
This project will use an interdisciplinary approach to elucidate the novel bioactive chemistry produced by T. hamatum that contributes to these agronomically important traits. Bioassay-guided fractionation (using advanced chromatographic/spectroscopic analysis i.e. MS and NMR) will be used to identify bioactive natural products from microcosm extracts of Trichoderma hamatum that provide protection of lettuce (Lactuca sativa) or brassicas against the soil pathogen Sclerotinia sclerotorium (Ss). In-soil capture of the identified chemical signals, from Trichoderma isolates and the host plants will be carried out by the insertion of reverse-phase coated fibres into Trichoderma-amended soil environment of plants, in the presence or absence of Ss, and then elution/analysis of the captured compounds. This technique will shed light on the identity of the causal metabolites involved in potential enhancement of root defence against herbivores eg. clover root weevils, Sitona lepidus.
This interdisciplinary project will provide training in aspects of natural product chemistry, chemical ecology and microbiology. It will be based in Rothamsted in the lab of MB, where training in biological chemistry methods including bioassay-guided fractionation and analysis will be provided. The first year rotation will be based in MG's lab in Exeter. The candidate will train in generating microcosms, preparation of extracts with antibiotic activity from wild-type and mutant T. hamatum and undertake biological assays to evaluate Ss (or other pathogen) performance in a background of extracts, fractions and compounds.
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/M009122/1 | 01/10/2015 | 31/03/2024 | |||
| 1622285 | Studentship | BB/M009122/1 | 01/10/2015 | 30/09/2019 | Gareth Thomas |
| Description | Soil microorganisms communicate through the production of chemical compounds which can drive their ecological interactions. These interactions can occur between a beneficial fungus, which can protect plants from fungal disease, and the pathogenic fungus itself. Evidence from studies taking place on artificial growth medium suggests the physical interaction between beneficial and pathogenic fungi can lead to changes in the production of compounds by beneficial fungi, which play a role in the biocontrol response. This project focuses upon a novel, free-living, strain of the beneficial fungus Trichoderma hamatum, which exhibits a unique biocontrol and plant growth promotion (PGP) capabilities against pathogens such as Sclerotinia sclerotiorum. Whilst these biological activities are well reported, the causal metabolites produced by T. hamatum in these biological activities are currently unknown. We have shown that the detection of fungal compounds from soil, enabling us to assess the way in which compounds produced by the beneficial fungus change upon interaction with a pathogen, which can indicate a causal role for these compounds in the defence response, and plant growth promoting capabilities. This PhD work has established that co-culture of Trichoderma with S. sclerotiorum leads to the significant upregulation of compounds produced by Trichoderma, which could be playing a role in the defence response of the Trichoderma. |
| Exploitation Route | • This technique allows us to look more specifically at compounds significantly upregulated by a beneficial fungus in the presence of the pathogen which are likely activated by the pathogen, and therefore important in the biocontrol process. This could therefore lead to the discovery of novel classes of compounds involved in the suppression of fungal pathogens. • Understanding how biological control agents work (or don't work) in the field can facilitate the optimization of biocontrol agents, by seeing if compounds produced by the fungus in the lab are also produced in the field. Future outcomes for the project (i.e. publications and grant proposals) will be discussed with the supervisory team over the coming weeks |
| Sectors | Agriculture, Food and Drink,Environment |
| Description | Investigating the biological activities of non-volatile compounds produced by Trichoderma hamatum |
| Organisation | University of Warwick |
| Department | School of Life Sciences |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | The collaboration with Dr John Sidda and Professor Murray Grant, University of Warwick, has enabled us to use facilities in the life sciences department which are unavailable at Rothamsted. This has enabled us to set up more replications of plant growth experiment, and using the facilities at Warwick coupled to the expertise at Rothamsted in rhizosphere chemical signalling, it enables us to see if results from Rothamsted are consistent across different laboratories. I can then analyse the samples using Gas Chromatography and Coupled Gas Chromatography Mass Spectrometry to identify compounds involved in the biological activities of the fungus in the rhizosphere. Regular Skype meetings with our collaborators enable us to share data with the rest of the supervisory team, where we can all input on what we believe the next stages of the project should be. |
| Collaborator Contribution | Dr John Sidda, a post-doc in the laboratory group of Professor Murray Grant, has experience in microbiology and chemistry. Together, we have set up sterile plant growth experiments on a large scale, using different mutants of Trichoderma, against different isolates of S. sclerotiorum. Moreover, Dr Sidda has been focussing on the non-volatile aspects of Trichoderma chemistry, investigating the role of non-volatile compounds on the biocontrol of the economically important plant pathogen Sclerotinia sclerotiorum. Using bioassay guided fractionation and LC-MS, he can isolate specific compounds involved in the biocontrol response. This enables us to look at different classes of compounds compared to those being investigated at Rothamsted, which could be of biological significance to the biocontrol and plant growth promoting capabilities of the beneficial fungus. |
| Impact | The collaboration has enabled us to set up more treatments with the plant growth experiments, allowing us to see if the beneficial fungus has different biocontrol responses to different isolates of S. sclerotiorum, which we have established is the case. This demonstrates that pathogens of the same species, but of different geographical origin, behave differently and elicit different responses when challenged with a beneficial fungus. This provides an impetus to look at different species of pathogen altogether, to see how different soil pathogens could elicit different responses, and potentially unlock novel chemistries in Trichoderma hamatum. |
| Start Year | 2017 |
| Description | PhD: Characterisation of Chemical Signalling from Beneficial Trichoderma spp. |
| Organisation | University of Exeter |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | Principal PhD supervisor |
| Collaborator Contribution | Co-supervisor and collaborator |
| Impact | Work in progress |
| Start Year | 2015 |
| Description | PhD: Characterisation of Chemical Signalling from Beneficial Trichoderma spp. |
| Organisation | University of Warwick |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | Principal PhD supervisor |
| Collaborator Contribution | Co-supervisor and collaborator |
| Impact | Work in progress |
| Start Year | 2015 |
| Description | Outreach event at greenman festival, as part of the SWBio DTP 'Agriculture and Environment' research theme |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Other audiences |
| Results and Impact | Participated in the SWBio DTP outreach event at Greenman music festival. Took part in outreach activity from our stall 'the plant power station', which is composed of four substations, containing games and demonstrations which highlight the importance of global food security to the general public. |
| Year(s) Of Engagement Activity | 2018 |
| URL | https://www.swbio.ac.uk/2018/10/16/promoting-plant-power-green-man-festival/ |