The role of NO2 and nitrated electrophiles in Arabidopsis defense signaling

Nitrogen dioxide (NO2) is a reaction product of NO with molecular oxygen or ozone. In cellular metabolism, it can be produced by hemoglobins and peroxidases through one-electron oxidation of nitrite in the presence of H2O2 and is emitted by herbicide- and stress-treated plants (for references see Groß F, Durner J, Gaupels F (2013) Nitric oxide, antioxidants and prooxidants in plant defence responses, Front Plant Sci, 4: 419). NO2 oxidizes and nitrates (-NO2 group) electrophiles such as proteins, nucleotides and lipids.

We are interested in deciphering the role of NO2 and nitrated electrophiles in Arabidopsis defense signaling. To this end, we fumigate different wild type accessions and selected signaling mutants of Arabidopsis with high (ppm range) concentrations of NO2 before analyzing leave material for cell death symptoms, nitrite, S-nitrosothiols, nitrated proteins, reactive oxygen species and other signal molecules.