Doctorat candidate in plant science
Valérie Gravel lab
Title to come
My project compares how different doses of three UV wavelengths (UVA, 395-410 nm; UVB, 310-315 nm; and UVC, 254 nm) affect Botrytis cinerea (grey mould) on strawberry. Several studies have reported antimicrobial effects of UV light. UVC, the most commonly used, is highly damaging to living organisms and is applied as an abiotic strategy to reduce microbial load on a wide range of substrates, but it is also highly damaging to plants.
UV has a weaker antimicrobial effect but is better tolerated by plants and can stimulate the production of secondary metabolites, although it is phytotoxic at higher doses. UVA, which is abundant in sunlight, has been described as having little effect on microbes but a positive effect on plant defence. UVA and UVB have recently gained attention, and supplemental lighting at these wavelengths is now marketed as a defence strategy in controlled environment agriculture. UVC microdoses applied by robots in these environments is also becoming increasingly popular. Previous studies have shown that UVC can kill B. cinerea spores and mycelia at higher doses, and that UVB can reduce colony growth.
To compare the effects of these wavelengths on grey mould, three doses were selected: 5 kJ/m² (high), 1.5 kJ/m² (intermediate), and 0.5 kJ/m² (low). These doses were tested for their effects on spore induction, germination and on mycelial growth. We also tested whether direct treatment or priming of strawberry plants with these wavelengths and doses affects the plant’s interaction with B. Cinerea.
Bellino M, Waite-Cusic J, Wang Q. Multi-method in vitro assessment of ultraviolet-C treatment against conidia and hyphal fragments of Botrytis cinerea. Appl Environ Microbiol. 2025 Dec 23;91(12):e0141325. doi: 10.1128/aem.01413-25. Epub 2025 Nov 24. PMID: 41283669; PMCID: PMC12724258.
Forges, M., Bardin, M., Urban, L., Aarrouf, J., & Charles, F. (2020). Impact of UV-C Radiation Applied during Plant Growth on Pre- and Postharvest Disease Sensitivity and Fruit Quality of Strawberry. Plant disease, 104(12), 3239–3247. https://doi.org/10.1094/PDIS-02-20-0306-RE
Janisiewicz, W. J., Takeda, F., Glenn, D. M., Camp, M. J., & Jurick, W. M., 2nd (2016). Dark Period Following UV-C Treatment Enhances Killing of Botrytis cinerea Conidia and Controls Gray Mold of Strawberries. Phytopathology, 106(4), 386–394. https://doi.org/10.1094/PHYTO-09-15-0240-R