A role for oxalic acid generation in ozone‐induced signallization in Arabidopis cells

ABSTRACT Ozone (O3) is an air pollutant with an impact increasingly important in our industrialized world. It affects human health and productivity in various crops. We provide the evidences that treatment of Arabidopsis thaliana with O3 results in ascorbate‐derived oxalic acid production. Using cultured cells of A. thaliana as a model, here we further showed that oxalic acid induces activation of anion channels that trigger depolarization of the cell, increase in cytosolic Ca2+ concentration, generation of reactive oxygen species and cell death. We confirmed that O3 reacts with ascorbate in the culture, thus resulting in production of oxalic acid and this could be part of the O3‐induced signalling pathways that trigger programmed cell death. Ozone is now considered to be the most phytotoxic of all air pollutants and which impact is increasingly important. Ozone causes damages to both animals and plants. We provide the evidences that treatment of Arabidopsis cells with ozone results in ascorbate‐derived oxalic acid production, as a secondary toxicant. This could be part of ozone‐induced signaling pathways that triggers programmed cell death.