Multi-year study on the effects of elevated CO2 in mature oaks unravels subtle metabolic adjustments but stable biotic stress resistance
Authors: Sanchez-Lucas, R., Raw, M., Datta, A., Hawkins, K., Brettle, D., Platt, E. A., Ullah, S., Hart, K., Mayoral, C., Stegner, M., Kranner, I., Hayward, S. A., Pastor, V., MacKenzie, A. R., Luna, E.
A long‑term FACE experiment exposing 180‑year‑old Quercus robur to +150 ppm CO₂ showed seasonal declines in powdery mildew and insect herbivory but no consistent change in biotic stress incidence. Metabolomic analyses revealed widespread shifts in amino acid, Coenzyme A, and redox pathways, indicating extensive metabolic plasticity without altered resistance to pathogens or herbivores.
The study investigated unexpected leaf spot symptoms in Psa3‑resistant kiwifruit (Actinidia) germplasm, finding that Psa3 was detectable by qPCR and metabarcoding despite poor culturing. Metabarcoding revealed distinct bacterial community shifts in lesions versus healthy tissue, and whole‑genome sequencing identified diverse Pseudomonas spp. that, while not individually more pathogenic, could enhance Psa3 growth, suggesting pathogenic consortia on resistant hosts.