| This project going to be… | Experimental (lab/field based) |
| Email | gareth.thomas@rothamsted.ac.uk |
| Position held | Post-doctoral Research Scientist (Chemical Ecology) |
| Title of Project | Understanding the role of fruit-flies in Botrytis cinerea transmission: a chemical ecology approach |
| Institution Department and Address | Rothamsted Research |
| Harpenden, AL5 2JQ |
| United Kingdom |
| Full Name of Supervisor | Gareth Thomas |
| Date of Project Commencement | 03/07/2023 |
| Duration (weeks) | 8 |
| Brief Description of Project | Background: Grey mould is a disease caused by the fungal pathogen Botrytis cinerea; the primary pathogen of strawberries (1). Global losses caused by the pathogen are estimated to be $10-$100 billion annually (2). Current methods to control the pathogen include the application of fungicides, which can lead to the development of resistance, rendering them less effective, therefore more sustainable methods of control are needed. B. cinerea spores are spread through water, wind, and by insect vectors, including Drosophila melanogaster (3). To locate food sources, insects rely on a range of cues, including olfactory cues, through sensing volatile organic compounds (VOCs) produced by plants. Whilst the attraction of D. melanogaster towards healthy fruit VOCs is well-studied, the influence of B. cinerea inoculation of fruits on VOC profiles, and D. melanogaster behaviour, is unknown. Therefore, characterising VOCs produced by B. cinerea could provide novel insights into the role of D. melanogaster as a vector, leading to the development of Botrytis based semiochemical attractants/repellents to reduce the pathogen transmission by the vector, reducing post-harvest losses. Hypotheses: 1) Changes in strawberry VOC production occurs following pathogen inoculation 2) VOCs produced by B. cinerea inoculated on (a) Petri dishes and (b) Strawberries alter insect behaviour Objectives/methodology: 1) Perform VOC collections from B. cinerea grown on (a) agar and (b) strawberries, using dynamic headspace collections (weeks 1-4). Collected VOCs will be identified using Gas Chromatography (GC)/coupled GC-Mass Spectrometry (GC-MS), and statistical analyses of peak areas will enable discrimination of treatments based on VOC profiles to test hypothesis 1. 2) Determine behavioural responses of D. melanogaster to B. cinerea VOCs using (a) antennal electrophysiology, and (b) arena bioassays (weeks 4-8) (a) To determine which compounds from B. cinerea VOCs elicit antennal responses by D. melanogaster, GC-electroantennography (GC-EAG) will be used using chemical extracts collected in objective 1). (b) To determine whether D. melanogaster shows a preference for B. cinerea inoculated fruit versus healthy fruit, arena bioassays will be performed. For further information on methods, see (4) in further reading. Student development: This multidisciplinary project will equip the student with skills including: 1) Handling chemicals safely in the lab 2) Microbiology – Culturing fungi in vitro and in planta 3) Chemical Ecology – Performing VOC collections from B. cinerea and fruit material (dynamic headspace collections, analytical chemistry (GC/GC-MS)) 4) Entomology – Using bioassays to determine the role of B. cinerea VOCs on insect behaviour. 5) Experimental design/statistical analysis using statistical packages (Genstat, R Studio). |
| Attach the recommended reading for the project | (1) Petrasch, S., Knapp, S. J., van Kan, J. A. L., Blanco‐Ulate, B. (2019). Grey mould of strawberry, a devastating disease caused by the ubiquitous necrotrophic fungal pathogen Botrytis cinerea. Molecular Plant Pathology, 2016, (6), 877–892. https://doi.org/10.1111/mpp.12794 |
| (2) Weiberg, A., Wang, M., Lin, F.-M., Zhao, H., Zhang, Z., Kaloshian, I., Huang, H.-D., Jin, H. (2013). Fungal Small RNAs Suppress Plant Immunity by Hijacking Host RNA Interference Pathways. Science, 342(6154), 118–123. https://doi.org/10.1126/science.1239705 |
| (3) Louis, C., Girard, M., Kuhl, G. and Lopez-Ferber, M. (1996). Persistence of Botrytis cinerea in its vector Drosophila melanogaster. Phytopathology, 86, 934–939 |
| (4) Thomas, G. (2021). Using the Odour of Bacteria to tackle Acute Oak Decline. BSPP blog. https://www.bspp.org.uk/using-the-odour-of-bacteria-to-tackle-acute-oak-decline/ |
