Fig. 1.

Schematic model of NO₂-Ln signaling. Pathway 1 indicates that NO₂-Ln is able to induce a defense mechanism through the induction of the chaperone network and the increase in the expression of ascorbate peroxidase enzyme. This latter may be involved in the alleviation of the oxidative stress generated by the overproduction of ROS such as H₂O₂. Furthermore, NO₂-Ln is a NO donor being therefore implicated in the wide range of actions in which this molecule is involved (pathway 2). The electrophilic ability of this nitro-fatty acid could contribute to the signaling actions involving NO₂-FAs (pathway 3) and, under nitro-oxidative stress conditions, the oxidation of Michael adducts may occur with subsequent nitroalkene release (pathway 4) and the observed antioxidant properties of these molecules. NO: nitric oxide; HSP: heat shock protein; APX: ascorbate peroxidase.