Nitro-fatty acids in plant signaling: New key mediators of nitric oxide metabolism

• Published in: Redox biology Vol. 11; pp. 554 - 561
• Main Authors: Mata-Pérez, Capilla, Sánchez-Calvo, Beatriz, Padilla, María N., Begara-Morales, Juan C., Valderrama, Raquel, Corpas, Francisco J., Barroso, Juan B.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-04-2017; Elsevier
• Subjects: alpha-Linolenic Acid - metabolism; Antioxidant response; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis - physiology; Defense response; Fatty Acids - genetics; Fatty Acids - metabolism; Nitric Oxide - metabolism; Nitric oxide donor; Nitro-fatty acids; Nitro-linolenic acid; Oxidative stress; Plants; Proteome - genetics; Proteome - metabolism; Reactive Nitrogen Species - metabolism; Review; Signal Transduction - genetics; Signaling molecule; Oxidative stress; Nitro-fatty acids; Nitric oxide donor; Antioxidant response; Signaling molecule; Nitro-linolenic acid; Plants; Defense response
• ISSN: 2213-2317; 2213-2317
• DOI: 10.1016/j.redox.2017.01.002

Recent studies in animal systems have shown that NO can interact with fatty acids to generate nitro-fatty acids (NO2-FAs). They are the product of the reaction between reactive nitrogen species and unsaturated fatty acids, and are considered novel mediators of cell signaling based mainly on a proven anti-inflammatory response. Although these signaling mediators have been described widely in animal systems, NO2-FAs have scarcely been studied in plants. Preliminary data have revealed the endogenous presence of free and protein-adducted NO2-FAs in extra-virgin olive oil (EVOO), which appear to be contributing to the cardiovascular benefits associated with the Mediterranean diet. Importantly, new findings have displayed the endogenous occurrence of nitro-linolenic acid (NO2-Ln) in the model plant Arabidopsis thaliana and the modulation of NO2-Ln levels throughout this plant's development. Furthermore, a transcriptomic analysis by RNA-seq technology established a clear signaling role for this molecule, demonstrating that NO2-Ln was involved in plant-defense response against different abiotic-stress conditions, mainly by inducing the chaperone network and supporting a conserved mechanism of action in both animal and plant defense processes. Thus, NO2-Ln levels significantly rose under several abiotic-stress conditions, highlighting the strong signaling role of these molecules in the plant-protection mechanism. Finally, the potential of NO2-Ln as a NO donor has recently been described both in vitro and in vivo. Jointly, this ability gives NO2-Ln the potential to act as a signaling molecule by the direct release of NO, due to its capacity to induce different changes mediated by NO or NO-related molecules such as nitration and S-nitrosylation, or by the electrophilic capacity of these molecules through a nitroalkylation mechanism. Here, we describe the current state of the art regarding the advances performed in the field of NO2-FAs in plants and their implication in plant physiology.
Nitro-fatty acid signaling in plants. 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 some antioxidant enzymes such as APX. 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 NO2-FA release (pathway 4) and the observed antioxidant properties of these molecules. NO: nitric oxide; HSP: heat shock protein; APX: ascorbate peroxidase. [Display omitted]
•Nitro-Linolenic acid is an endogenous molecule whose levels are modulated throughout Arabidopsis development.•Nitro-Linolenic acid induces the molecular chaperone network in Arabidopsis.•Nitro-fatty acids are able to act as a signaling mediators in the plant-defense mechanism in abiotic and oxidative stress situations, setting up a defense response against cell damage.•Nitro-fatty acids have been demonstrated to be in vitro and in vivo NO donors.•The nitro-fatty acid detection in other plant species highlight a ubiquitous distribution of nitro-fatty acids in plant kingdom and the potential signaling actions of these molecules in plant systems.