Endogenous Biosynthesis of S-Nitrosoglutathione From Nitro-Fatty Acids in Plants

Nitro-fatty acids (NO 2 -FAs) are novel molecules resulting from the interaction of unsaturated fatty acids and nitric oxide (NO) or NO-related molecules. In plants, it has recently been described that NO 2 -FAs trigger an antioxidant and a defence response against stressful situations. Among the properties of NO 2 -FAs highlight the ability to release NO therefore modulating specific protein targets through post-translational modifications (NO-PTMs). Thus, based on the capacity of NO 2 -FAs to act as physiological NO donors and using high-accuracy mass-spectrometric approaches, herein, we show that endogenous nitro-linolenic acid (NO 2 -Ln) can modulate S -nitrosoglutathione (GSNO) biosynthesis in Arabidopsis . The incubation of NO 2 -Ln with GSH was analyzed by LC-MS/MS and the in vitro synthesis of GSNO was noted. The in vivo confirmation of this behavior was carried out by incubating Arabidopsis plants with 15 N-labeled NO 2 -Ln throughout the roots, and 15 N-labeled GSNO (GS 15 NO) was detected in the leaves. With the aim to go in depth in the relation of NO 2 -FA and GSNO in plants, Arabidopsis alkenal reductase mutants ( aer mutants) which modulate NO 2 -FAs levels were used. Our results constitute the first evidence of the modulation of a key NO biological reservoir in plants (GSNO) by these novel NO 2 -FAs, increasing knowledge about S -nitrosothiols and GSNO-signaling pathways in plants.