Using volatile organic compounds to detect infection in trees
Can VOCs emitted by larch trees be used to detect infection by Phytophthora ramorum?
My research investigates whether volatile organic compounds (VOCs) emitted by larch (Larix spp.) trees can be used to detect infection by Phytophthora ramorum, the pathogen responsible for sudden larch death. By combining field-based VOC sampling with molecular diagnostics, the project aims to characterise both pathogen-associated microbial volatiles and changes in host plant emissions associated with infection.
To achieve this, VOCs are collected from larch branches, surrounding air, and soil using dynamic headspace sampling onto Tenax sorbent tubes, followed by thermal desorption gas chromatography–mass spectrometry (TD-GC-MS) analysis. Quantitative PCR (qPCR) is used to determine infection status from needle, bark, and root tissues collected from the same trees.
The project focuses on understanding how VOC profiles change across seasons and between infected and uninfected trees, with particular interest in stress-related green leaf volatiles and other compounds that may act as early indicators of disease. Ultimately, this work aims to improve understanding of plant–pathogen chemical interactions and explore the potential for VOC-based approaches to forest disease monitoring.
- Aim 1: Generate robust, high-resolution characterisation of VOC emissions from P. ramorum.
- Aim 2: Distinguish microbe-derived VOCs from plant-derived responses in P. ramorum x larch interactions.
- Aim 3: Establish whether VOC changes can reveal P. ramorum infection prior to visible symptom development.
- Aim 4: Test field-applicable VOC sampling approaches and infection detection VOCs in areas with known Phytophthora infection compared with areas where Phytophthora infection is absent.
