Arabidopsis lines with modified ascorbate concentrations reveal a link between ascorbate and auxin biosynthesis
Authors: Fenech, M., Zulian, V., Moya-Cuevas, J., Arnaud, D., Morilla, I., Smirnoff, N., Botella, M. A., Stepanova, A. N., Alonso, J. M., Martin-Pizarro, C., Amorim-Silva, V.
The study used Arabidopsis thaliana mutants with low (vtc2, vtc4) and high (vtc2/OE-VTC2) ascorbate levels to examine how ascorbate concentration affects gene expression and cellular homeostasis. Transcriptomic analysis revealed that altered ascorbate levels modulate defense and stress pathways, and that TAA1/TAR2‑mediated auxin biosynthesis is required for coping with elevated ascorbate in a light‑dependent manner.
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.