ORCID IDs: 0000-0002-6609-7242 (C.M.-P); 0000-0002-2210-9547 (B.S.-C.); 0000-0001-5284-8837 (J.J.-R.); 0000-0002-1814-9212 (F.J.C.); 0000-0002-9477-9195 (J.J.B.).Nitro-fatty acids (NO 2 -FAs) are the product of the reaction between reactive nitrogen species derived of nitric oxide (NO) and unsaturated fatty acids. In animal systems, NO 2 -FAs are considered novel signaling mediators of cell function based on a proven antiinflammatory response. Nevertheless, the interaction of NO with fatty acids in plant systems has scarcely been studied. Here, we examine the endogenous occurrence of nitro-linolenic acid (NO 2 -Ln) in Arabidopsis and the modulation of NO 2 -Ln levels throughout this plant's development by mass spectrometry. The observed levels of this NO 2 -FA at picomolar concentrations suggested its role as a signaling effector of cell function. In fact, a transcriptomic analysis by RNA-seq technology established a clear signaling role for this molecule, demonstrating that NO 2 -Ln was involved in plant defense response against different abiotic-stress conditions, mainly by inducing heat shock proteins and supporting a conserved mechanism of action in both animal and plant defense processes. Bioinformatics analysis revealed that NO 2 -Ln was also involved in the response to oxidative stress conditions, mainly depicted by H 2 O 2 , reactive oxygen species, and oxygen-containing compound responses, with a high induction of ascorbate peroxidase expression. Closely related to these results, NO 2 -Ln levels significantly rose under several abiotic-stress conditions such as wounding or exposure to salinity, cadmium, and low temperature, thus validating the outcomes found by RNA-seq technology. Jointly, to our knowledge, these are the first results showing the endogenous presence of NO 2 -Ln in Arabidopsis (Arabidopsis thaliana) and supporting the strong signaling role of these molecules in the defense mechanism against different abiotic-stress situations.

Linolenic acid (Ln) released from chloroplast membrane galactolipids is a precursor of the phytohormone jasmonic acid (JA). The involvement of this hormone in different plant biological processes, such as responses to biotic stress conditions, has been extensively studied. However, the role of Ln in the regulation of gene expression during abiotic stress situations mediated by cellular redox changes and/or by oxidative stress processes remains poorly understood. An RNA-seq approach has increased our knowledge of the interplay among Ln, oxidative stress and ROS signaling that mediates abiotic stress conditions. Transcriptome analysis with the aid of RNA-seq in the absence of oxidative stress revealed that the incubation of Arabidopsis thaliana cell suspension cultures (ACSC) with Ln resulted in the modulation of 7525 genes, of which 3034 genes had a 2-fold-change, being 533 up- and 2501 down-regulated genes, respectively. Thus, RNA-seq data analysis showed that an important set of these genes were associated with the jasmonic acid biosynthetic pathway including lypoxygenases (LOXs) and Allene oxide cyclases (AOCs). In addition, several transcription factor families involved in the response to biotic stress conditions (pathogen attacks or herbivore feeding), such as WRKY, JAZ, MYC, and LRR were also modified in response to Ln. However, this study also shows that Ln has the capacity to modulate the expression of genes involved in the response to abiotic stress conditions, particularly those mediated by ROS signaling. In this regard, we were able to identify new targets such as galactinol synthase 1 (GOLS1), methionine sulfoxide reductase (MSR) and alkenal reductase in ACSC. It is therefore possible to suggest that, in the absence of any oxidative stress, Ln is capable of modulating new sets of genes involved in the signaling mechanism mediated by additional abiotic stresses (salinity, UV and high light intensity) and especially in stresses mediated by ROS.

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Currently, there is a growing interest in the use of non-Saccharomyces yeast to enhance the aromatic quality of wine, with pure or mixed cultures, as well as sequential inoculation. Volatile components of wines were closely related to their sensory quality. Hence, to study the evolution of volatile compounds during fermentation was of great interest. For this, sampling methods that did not alter the volume of fermentation media were the most suitable. This work reports the usefulness of headspace sorptive extraction as non-invasive method to monitor the changes in volatile compounds during fermentation. This method allowed monitoring of 141 compounds throughout the process of fermentation by Saccharomyces cerevisiae and Lachancea thermotolerans strains. Both strains showed a similar ability to ferment a must with high sugar content. The S. cerevisiae strain produced higher amount of volatile compounds especially esters that constitutes fruity aroma than L. thermotorelans.