Nitroalkylation Mediated by Nitro‐Fatty Acids Is Involved in Key Physiological Processes During Arabidopsis thaliana Development

ABSTRACT Nitro‐fatty acids (NO 2 ‐FAs) are potent electrophiles that react with nucleophilic residues in proteins (cysteines, histidines and lysines) via a process known as nitroalkylation. This reversible post‐translational modification (PTM) functions as a selective signalling mechanism by modulating the structure, transport, and catalysis of target proteins. In the present work, in vivo nitroalkylated proteins targets by nitro‐oleic acid (NO 2 ‐OA), nitro‐linoleic acid (NO 2 ‐LA) and NO 2 ‐Ln have been identified in different Arabidopsis development, including the seed, vegetative, generative and senescence stages. The results reveal that nitroalkylation is a PTM that occurs throughout the development of Arabidopsis, primarily during the vegetative and generative stages. This modification predominantly affects proteins involved in energy metabolism, redox coenzymes and stress responses. Although all three NO 2 ‐FAs interact with the three amino acids mentioned, cysteine is the primary target. However, its adducts are significantly more labile and redox‐sensitive than those formed with histidine or lysine. Overall, these results suggest that nitroalkylation constitutes a reversible post‐translational modification linked to the redox state. This regulation could participate in modulating the plasticity of energy flow, contributing to maintaining homoeostasis throughout the life cycle and resilience to environmental stress. Data are available via ProteomeXchange with identifier PXD060471.