BIFoR are part of the Action Oak network. Action Oak brings together representatives from charities, landowners and government to develop a coordinated plan to identify and tackle issues threatening our native oak trees. BIFoR continues to support the Action Oak (AO) initiative including via a very well attended Action Oak session at the BIFoR conference in January 2020. In October 2021, two new postgraduate students joined our team; Emily Grace (oak bacteriophages) and Vanja Milenkovic (soil and tree health) both will be affiliated to Action Oak.
At our research woodland - the BIFoR FACE facility - the forest stand has the most complex canopy structure of all forest FACE experiments to date, dominated by up to 25m tall mature pedunculate oak (Quercus robur) (Norby et al., 2016).
Two postdoctoral research fellows, Dr Rosa Sanchez-Lucas (working with Dr Estrella Luna-Diez) and Dr Thomas Welch (working with Dr Graeme Kettles), are carrying out research projects examining defence mechanisms in oak that can help to protect the tree from pathogen infection. One aim has been to establish and optimise protocols for performing an oak seedling diversity panel screen against the Acute Oak Decline (AOD) bacterial complex and the oak powdery mildew (PM) fungus.
A new protocol for generating stem infections of oak seedlings with Acute Oak Decline bacteria and a medium-throughput image analysis platform for the quantification of foliar disease symptoms induced by the Powdery Mildew fungus on oak leaves has been developed. These will allow experiments to be done that can identify two main components of defence: priming of resistance; and identification of resistance alleles that help fight off infections by pathogens.
Dr Kettles received funding from the British Society of Plant Pathology (BSPP) and the Royal Society of Biology (RSB) to initiate projects aimed at developing tools to understand tree disease resistance, and investigate the microbial communities (microbiomes) that inhabit oak trees. These projects, started by two undergraduate summer students (Adriana Iamandi and Chris Griffin) and have since been continued back in the lab at the Edgbaston campus.
Dr Sabrine Dhaouadi's research includes several approaches to be employed for the establishment of robust pathosystem models that underpin a detailed examination of infection and disease progression. This research will be applied to the main tree diseases in the UK: acute oak decline, bacterial canker of cherry and ash, bleeding canker of horse chestnut, diseases that had emerged in both UK and Europe within the last 20 years.
Kieran Clark: KRC026@student.bham.ac.uk
Supervisors: Prof. Pola Goldberg Oppenheimer (Chem Eng), Dr Estrella Luna Diez (Bio)
Year of Study: First
PhD Draft Title: Study and Fabrication of Rapid Engineered Spectroscopic Technology (FoRESTech) for Identification of Filamentous Pathogens in Leaves
Info: This project aims to use the non-destructive and versatile method of Raman spectroscopy as a diagnostic tool to probe biomolecular changes to the surface structure of the leaf during the course of ash dieback and oak powdery mildew infections. A microscopic survey of the surface of the leaf is conducted and areas of non-vein, secondary vein and primary vein tissues are identified. An 830nm laser is used to probe these tissue types and Raman spectra are formed for the healthy and infected classes for ash and oak leaves both grown in ambient and elevated carbon dioxide environments. An initial study, conducted for a healthy oak leaf grown in an ambient carbon dioxide environment, indicated spectral similarity between all tissue types with the primary vein tissue being the most dissimilar. The major differences between the tissue type spectra were identified between the pectin region at 800-900cm-1; the carotenoid peaks at 1158cm-1 and 1527cm-1; and the lignin peak at 1610cm-1. The produced spectra will be further compared in different ways using advanced computational methods to identify spectral differences. These differences will be attributed to either biomarkers of disease, structural differences between growth conditions or further tissue type differences. Finally, a handheld Raman spectrometer will be developed to identify these biomarker-related spectral changes to diagnose these diseases in the field.
Emily Grace - firstname.lastname@example.org
Supervisors: Professor Robert Jackson (Bio)
Year of Study: First
PhD draft title: Analysis of phage that infect oak pathogens and the dynamics of phage population changes and bacterial community change in a disease lesion
Info: There are currently no anti-microbial treatments available for AOD. However, bacteriophages (phages) are a biocontrol alternative to traditional antibiotic and copper compounds. Phages, viruses that infect and kill bacteria, have been proven to be effective treatments for several bacterial tree pathogens. This study aims to isolate phages which infect the four AOD-associated bacteria species and characterise them via several assays to assess their suitability as biocontrol agents. It is also important to identify the extent and consequences of phage resistance; therefore, the coevolution dynamics of these different phages and bacteria species will be tracked over a period of 7 days, both in vitro and in planta. Seasonal sampling of infected trees will be performed to determine how phage diversity changes over symptom progression. Dependent on these findings, cocktails of the different phages will be trialled to assess their ability to reduce AOD symptoms and bacteria prevalence.
*Mark Raw - MXR816@student.bham.ac.uk
Supervisors: Estrella Luna Diez (Bio), Scott Hayward (Bio)
Year of study: Second
PhD Draft Title: Priming of defence in an elevated CO2 world
PhD: Priming of defence in an elevated CO2 world - Rising CO2 levels are a reality of our current world, however the impact of this on plant species is still little understood. Elevated CO2 is believed to result in increased growth in some species however there are reports that elevated levels could negatively impact on plant defence making them more susceptible to pests & diseases. This project aims to understand how elevated CO2 will impact oak defence priming in both juvenile & mature oak trees against the oak pathogen powdery mildew & insect herbivores. This knowledge will allow humans to better assess risks to future forests & allow for better protection of these vital organisms.
Further information: Poster 2021
Jiaqi Wei: email@example.com
Supervisors: Prof Robert Jackson (Bio), Dr Graeme Kettles (Bio)
Year of study: First
PhD (draft) title: Evaluating the threat of Xylella on UK trees
Info: Xylella fastidiosa is a bacterium that is endemic to central America. It is an established pathogen in the US and is a recently emerging pathogen causing devastating disease in southern Europe. Presently, they are limited to Italy, Portugal, Spain and France, but detection of infected plants has been found in other countries in Europe triggering control and eradication procedures. Tree species like ash and oak have also been observed with Xylella infections in Europe, highlighting the wide host range of the pathogen.
There is considerable concern around the potential threat to the UK’s horticulture and ecosystem, particularly to trees, should Xylella establish in the country and thus it is important that investment is made to fully understand the threat the pathogen poses. This will help with identifying the potential hosts for the pathogen and whether any resistance exists in the plant population. It will also help with identification and monitoring as well as considering the risk of widespread disease spread.
BIFoR postdoctoral researchers and Biosciences undergraduate students preparing oak acorns for planting in the glasshouses.
Dr Carolina Mayoral at the BIFoR FACE woodland laboratory - photosynthesis measurements.