Plant Health Undergraduate Studentship 2019 projects
The following studentship projects took place over summer 2019
Applications are now open for funding to host one of nine Plant Health Undergraduate Studentships over summer 2020.
We are grateful to Defra, BSPP, N8 AgriFood and the David Colegrave Foundation for funding the 2019 programme.
Below-ground controls of oak decline
Host: University of Manchester
Supervisor: Agnes Ardanuy
Oak decline episodes in the UK have been associated with different combinations of biotic and abiotic factors that make trees more susceptible to further stresses, like disease, which in some cases leads to tree death.
Recent work shows that mutualistic root-associated (ectomycorrhizal) fungi could be key in shaping tree tolerance to stress, partly through the ability of the fungi to acquire growth-limiting nutrients and water from soil. However, little is known about the importance of the association of oaks with ectomycorrhizal fungi on the tolerance to successive stresses.
In this project, we will try to cover this gap by evaluating the tolerance of oaks (Quercus robur) to herbivory and drought, either alone or in combination. We will investigate these interactions when the trees are grown in their own or an ‘alien’ soil; this latter approach will illustrate how oak seedlings might respond to new environments where the populations of compatible mycorrhizal partners are low.
This multifactorial experimental set-up will give insights on how the defence of oak trees is shaped by interacting stressors in own and ‘alien’ soil. The results of this study will help to understand oak decline and seedling establishment in new environments.
Safeguarding UK hop production: validating race-specific diagnostics tools for Verticillium albo-atrum
Host: NIAB EMR, Kent
Supervisor: Helen Cockerton
The fungal plant pathogen which causes Verticillium wilt has had a significant impact on the UK hop industry.
This detrimental pathogen has led to the restriction of UK hop plant movement; this embargo aims to prohibit the spread of the pathogen within hop material. Reports indicate that the use of disease resistant hop varieties has led to the evolution of highly virulent isolates of the pathogen.
This project will validate existing and newly developed molecular diagnostic tests to identify the highly virulent strains of the fungus. This work will support the understanding of the application and resilience of resistance genes in the field.
Stop them in their tracks: disrupting the temporal regulators of cyst nematode parasitism
Host: University of Cambridge
Supervisor: Sebastian Eves-van den Akker
The potato cyst nematodes Globodera rostochiensis and G. pallida are devastating plant-parasites of global economic importance, present on both the USDA and EPPO quarantine organism lists.
These nematodes produce “effector” proteins in sequential waves, inject them into the plant cell, and re-programme plant root cells into a novel tissue.
This project aims to disrupt effector regulation over time. In preparation for this project we have:
- conducted a genome-wide analysis of gene expression across the life cycle to categorize clusters of genes that are regulated at discrete times of infection, and
- conducted a within-cluster connectivity analysis to identify the most highly connected transcription factors within each cluster, thereby curating a list of putative “temporal regulators”.
The goals of this project are to:
- Silence putative temporal regulators by exogenous application of double stranded RNA to Juvenile nematodes.
- Confirm a role in regulation by measuring the disruption in expression of the targeted regulator, and the concerted disruption in expression of associated effectors by RNAseq.
This project will advance understanding of quarantine pests and, given that effectors are required for successful parasitism, may highlight attractive targets for control.
Development of combination phage therapy against Ralstonia solanacearum plant pathogenic bacterium
Host: University of York
Supervisor: Ville-Petri Friman
Current food systems are vulnerable to plant pathogens that are difficult to control with highly toxic agrochemicals.
Ralstonia solanacearum, a causative agent of bacterial wilt disease has both global distribution and an unusually wide host range, being able to infect over 200 plant species including many economically important crops. In the UK, R. solanacearum causes potato brown rot. Crucially, no effective control method of R. solanacearum exists at the moment.
This summer project will develop a novel way to control bacterial wilt disease outbreaks using naturally occurring, Ralstonia-specific viruses (phages) that infect and kill the pathogen. The project will build upon existing projects providing student access to multiple pathogen and phage strains.
Traditionally, two shortcomings of phage therapies have been the limited infectivity range of phages and rapid evolution of phage resistance. Here we will overcome these limitations by developing functionally robust phage combinations that have very broad infectivity range and that impose weak selection for phage resistance evolution.
To achieve this, we will use a combination of short-term model biocontrol experiments in vitro to study pathogen resistance evolution to phages at phenotypic and molecular level.
Assessment of Psyllid vectors of Lso in the UK and their potential risk to agriculture
Host: Science and Advice for Scottish Agriculture (SASA), Edinburgh
Supervisor: Fiona Highet
The bacterium, “Candidatus Liberibacter solanacearum” (Lso), causes disease in several important crops, including carrots and potato.
A recent report by SASA has confirmed the presence of Lso in a native Scottish psyllid species, Trioza anthrisci, a species that feeds on several weed plants. This was the first finding of Lso in this species and strongly suggests that Lso is present in the UK in weed host plants.
What is not clear is the risk of this psyllid, and potentially other Lso carrying native psyllid species, in vectoring disease to agriculturally important crops.
This project aims to continue psyllid field survey work for the detection of Lso along with investigating the risk to agriculture of Lso haplotypes known to be in Scotland through transmission studies.
Students will gain a range of experiences in the field of molecular biology, planning and running experiments, interpreting results and writing up their work in a scientific format.
Life cycle and biology of an emergent pest, the agapanthus gall midge
Host: RHS, Wisley
Supervisor: Hayley Jones
The agapanthus gall midge, Enigmadiplosis agapanthi, causes damage to the popular ornamental plant Agapanthus.
The midge larvae form galls in the flower buds, deforming them and stopping their flowering. It was first discovered in the UK in 2014, and at that time was new to science.
It was subsequently added to the UK Plant Health Risk Register. This pest is a major concern to Agapanthus growers, both in industry and home gardens, but its novelty means there is a real lack of information about its biology and life cycle.
Working with the scientists that first intercepted the pest, this project will use field observations and laboratory rearing to answer questions about the midge including:
- How deep underground do the midge larvae pupate?
- Is pupation time affected by temperature?
- Where and when does the female lay eggs on the plant?
- How long do eggs take to hatch and the larvae take to travel into the flower buds?
This project will gather essential life cycle information. The knowledge gained will inform the development and targeting of control options, with the aim of improving the economic stability of Agapanthus breeders and nurseries, and empowering gardeners to protect their garden plants from this pest.
Microbial profiling of the oak tree phyllosphere in response to changing atmospheric carbon dioxide levels
Host: University of Birmingham
Supervisor: Graeme Kettles
The surfaces of plants and animals (e.g. leaves, roots or skin) are colonised by numerous types of microbes. These communities of microbes are termed microbiomes, and can have health benefits for the organisms that they inhabit, such as protecting against pathogens.
In comparison to other plants, little is known about the microbiomes of trees.
This project will investigate the microbiome that exists on the leaves of oak trees, and how it might be influenced by increasing atmospheric carbon dioxide (CO2) concentration.
Leaves will be sourced from oak trees at the BIFoR-FACE climate change experiment, where some will have developed under high CO2 conditions designed to mimic the earth’s atmosphere 30 years into the future.
This project will test whether these different growth conditions can change the species of bacteria and fungi that make up the oak leaf microbiome.
We will also assess whether any of the microbes isolated from leaves can have a protective effect on oak trees, by limiting growth of bacteria associated with the Acute Oak Decline (AOD) disease.
Ability to perform work at heights may be required for this project.
Towards curbing the ash dieback epidemic
Host: NIAB EMR, Kent
Supervisor: Matevz Papp-Rupar
European ash (Fraxinus excelsior) is recognised as an ecological keystone species with large commercial importance. Large proportions of European ash populations are being devastated by ash dieback (ADB) which is categorised as a priority for regulation and management in UK Plant Health Risk Register.
Disease is caused by invasive ascomycete fungus Hymenoscyphus fraxineus. This pathogen is aggressive with high mortality in seedlings and new plantings while older trees develop chronic infections which are often fatal.
Remarkably, F. excelsior trees with low susceptibility to ADB were found across UK and we are investigating the basis of the resistance within BBSRC funded ‘Retaining the Ashes’ project.
Our preliminary data suggests that ascospore germination and attachment is compromised in more resistant ash lines. Along with researchers in Germany, we have also noted differences in epiphytes present on susceptible and resistant ash leaves.
This project aims to complement ‘Retaining the Ashes’ project by profiling of antimicrobial compounds in ash leaves and conducting initial assessment of microbiome associated with ADB susceptible and resistant ash lines in UK.
This project will use variety of concepts and methodologies with the aim to help potential student to become a well-rounded plant pathologist ready for future challenges.
This project will involve working with media that contains oat meal, potato dextrose and yeast extract, and is not appropriate for those with allergies.
Using a multi-disciplinary approach to tackle a formidable foe - wheat stem rust
Host: John Innes Centre, Norwich
Supervisor: Diane Saunders
Wheat rusts are known as the “polio of agriculture” due to the threat they pose to wheat production worldwide.
As is common among rust pathogens, they require two hosts to complete their life cycles, undertaking asexual reproduction on cereals and complete sexual reproduction on Berberis, where recombination can lead to emergence of novel genetic combinations.
Eradication of common barberry (B. vulgaris) in the UK drove stem rust to almost complete extinction. However, over the past decade, barberry planting has re-initiated and stem rust has re-emerged in western Europe.
To assess and mitigate the risk of sexual variants emanating from barberry infecting cereal crops we need accurate biological data on spore release. Using a citizen science approach, we are currently mapping the locations of barberry bushes across the UK.
This studentship project will utilise this information to assess the number and viability of sexual spores found at many of these locations on barberry.
This data will then feed into models assessing the risk to cereal crops under different environmental scenarios. This will contribute to broad assessments of the probability of positive and negative outcomes of factors generating rust epidemics, including barberry planting, on a large scale throughout the UK.