Mutations in the pantothenate kinase 2 gene (PANK2) are the cause of pantothenate kinase-associated neurodegeneration (PKAN), the most common form of neurodegeneration with brain iron accumulation. Although different disease models have been created to investigate the pathogenic mechanism of PKAN, the cascade of molecular events resulting from CoA synthesis impairment is not completely understood. Moreover, for PKAN disease, only symptomatic treatments are available. Despite the lack of a neural system, Saccharomyces cerevisiae has been successfully used to decipher molecular mechanisms of many human disorders including neurodegenerative diseases as well as iron-related disorders. To gain insights into the molecular basis of PKAN, a yeast model of this disease was developed: a yeast strain with the unique gene encoding pantothenate kinase CAB1 deleted, and expressing a pathological variant of this enzyme. A detailed functional characterization demonstrated that this model recapitulates the main phenotypes associated with human disease: mitochondrial dysfunction, altered lipid metabolism, iron overload, and oxidative damage suggesting that the yeast model could represent a tool to provide information on pathophysiology of PKAN. Taking advantage of the impaired oxidative growth of this mutant strain, a screening for molecules able to rescue this phenotype was performed. Two molecules in particular were able to restore the multiple defects associated with PKAN deficiency and the rescue was not allele-specific. Furthermore, the construction and characterization of a set of mutant alleles, allowing a quick evaluation of the biochemical consequences of pantothenate kinase (PANK) protein variants could be a tool to predict genotype/phenotype correlation.

Lettuce (Lactuca sativa L., Asteraceae) is a popular vegetable leafy crop playing a relevant role in human nutrition. Nowadays, novel strategies are required to sustainably support plant growth and elicit the biosynthesis of bioactive molecules with functional roles in crops including lettuce. In this work, the polyphenolic profile of lettuce treated with glutamic acid (GA), humic acid (HA), and their combination (GA + HA) was investigated using an untargeted metabolomics phenolic profiling approach based on high-resolution mass spectrometry. Both aerial and root organ parts were considered, and a broad and diverse phenolic profile could be highlighted. The phenolic profile included flavonoids (anthocyanins, flavones, flavanols, and flavonols), phenolic acids (both hydroxycinnamics and hydroxybenzoics), low molecular weight phenolics (tyrosol equivalents), lignans and stilbenes. Overall, GA and HA treatments significantly modulated the biosynthesis of flavanols, lignans, low molecular weight phenolics, phenolic acids, and stilbene. Thereafter, antioxidant capacity was evaluated in vitro with 2,2-diphenyln-1-picrylhydrazyl (DPPH), 2,2′-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and cupric ion reducing antioxidant capacity (CUPRAC) assays. In addition, this study examined the inhibitory properties of enzymes, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), tyrosinase, alpha-amylase, and alpha-glucosidase. Compared to individual treatments, the combination of GA + HA showed stronger antioxidant abilities in free radical scavenging and reducing power assays in root samples. Moreover, this combination positively influenced the inhibitory effects of root samples on AChE and BChE and the tyrosinase inhibitory effect of leaf samples. Concerning Pearson’s correlations, antioxidant and enzyme inhibition activities were related to phenolic compounds, and lignans in particular correlated with radical scavenging activities. Overall, the tested elicitors could offer promising insights for enhancing the functional properties of lettuce in agricultural treatments.

Despite the growing evidence on unique and unpredictable impact of stress combination over plants, waterlogging-combined stresses effects are still underexplored. Under those conditions, besides the impairment of plant aerial parts, the root system is particularly vulnerable, leading to consequences on plant survival. Here, we report on the short-term exposure of soil-grown Arabidopsis thaliana L. to waterlogging alone and combined with cold, heat, and salinity to inspect their antagonistic, additive or synergistic effects in the rhizosphere. To this aim, root metabolic changes, exudation profiles, and microbial diversity were investigated using a combination of metabolomics and metagenomics, and their interaction was analysed through multi-omics data integration. In roots, waterlogging strongly affected metabolism compared to other single stresses, causing a down-accumulation of targeted classes of compounds including, phenylpropanoids, sterols, terpenoids, and alkaloids. Additive and synergistic effects were reported in roots under waterlogging combined with heat and cold stresses, respectively. Regarding root exudates, flavonoids, terpenoids, and alkaloids were the main classes of compounds affected. Waterlogging caused a down-accumulation of all classes except for coumarins, and mixed trends were observed in waterlogging-combined stresses, with waterlogging-salinity stresses resulting in an ameliorating effect. Even though microbial communities' alpha- and beta-diversity remained stable, suggesting their resilience under short-term exposure, specific taxa modulation was recorded under each condition. Overall, these results contribute to understanding the hierarchical impact of waterlogging on root metabolism and exudation, influencing rhizosphere interactions. This multi-omics approach advances our understanding of plant stress responses and microbial dynamics, paving the way for future studies on adaptive mechanisms.

Melatonin (MLT) is an indole derivative that exhibits hormone‐like activities in plants, regulating multiple aspects of growth and development. Due to its role in mitigating oxidative stress and facilitating osmoprotectant accumulation, MLT enhances abiotic stress tolerance, although the pathways and metabolic mechanisms involved remain unclear despite being studied in various crops. This work aimed to investigate the changes elicited by the exogenous MLT application at different concentrations (10, 50, 150 μM) and its role in mitigating the salinity stress in Lactuca sativa L. through metabolomics and phenotyping approaches. Our results clearly indicated that MLT increases photosynthetic efficiency at high dosage (150 μM) at either early or late salinity stress conditions ( p < 0.01). Untargeted metabolomics provided insight into the significant effect of salinity and MLT ( p < 0.01 in both cases, according to multivariate chemometrics), mediated by a broad reprogramming involving secondary metabolism, phytohormones, fatty acids and amino acids biosynthesis. In detail, 150 μM MLT induced an adjustment of the phytohormones profile to reduce the salinity‐induced damages. Our findings support the well‐known potential of melatonin in alleviating salinity stress. These findings address existing challenges in studying the molecular effects of MLT in mitigating abiotic stress, providing insights into the biochemical pathways that drive its effectiveness. In this sense, further research is acknowledged to provide a multidisciplinary high throughput perspective leading to its exploitation in a wide range of crops of agricultural and economic importance.

Five Salsola species have been studied as sources of bioactive compounds using a comprehensive, untargeted metabolomic and bioactivity assessment. Plant material was extracted using ethyl acetate (EA), water, and methanol (MeOH). S. ruthenica exhibited the highest total phenolic content (46.04 mg GAE/g, MeOH extract) and antioxidant capacity (DPPH: 47.21 mg TE/g; ABTS: 97.40 mg TE/g; CUPRAC: 141.38 mg TE/g; FRAP: 80.30 mg TE/g). Extracts of S. stenoptera and S. ruthenica showed potent cholinesterase inhibition, while S. crassa was notably active against tyrosinase. A total of 265 metabolites were annotated, revealing strong solvent- and species-specific differences in phenolic composition, as confirmed by AMOPLS analysis. Flavanols, anthocyanins, and lignans emerged as the major chemotaxonomic markers, based on PCA, contributing the most to the total variance. Strong correlations were observed between TPC and CUPRAC (r = 0.93) and between flavanols and DPPH (r = 0.70), suggesting functional relevance of these compounds in redox activity, confirming the importance of different classes of phenolic constituents. VIP markers also revealed species- and solvent-specific enrichments of metabolites. Regularized canonical correlation analysis (rCCA) further linked specific metabolites, namely Quercetin 3-O-glucosyl-xyloside and 6″-O-Acetylgenistin, the flavanone sakuranetin, the lignans Secoisolariciresinol, Anhydro-secoisolariciresinol, and Medioresinol, and p-Coumaric acid ethyl ester, with antioxidant functions. These findings underscore the pharmacological potential of Salsola species and highlight the importance of valorizing metabolic diversity in the search for new sources of health-promoting natural compounds. Furthermore, the work shows the need for a tailored solvent selection in bioactivity-guided phytochemical research.

Halophytic plants possess a huge range of active constituents and medicinal benefits. In this study, extracts (water, ethanol, ethyl acetate, dichloromethane, and n-hexane) of two halophytes of the genus Petrosimonia (P. brachiata and P. nigdeensis) were investigated for their phytochemical profiles and pharmacological properties. The phytochemical profiles of both species were investigated using an untargeted metabolomics approach based on high-resolution mass spectrometry. The two species show different polyphenolic profiles and these are influenced by the different extraction solvents used. The same extracts were used for different bioactivity assays. The results show that all extracts yielded total flavonoid and phenolic contents of 11.14–24.22 mg GAE/g and 3.15–22.03 mg RE/g, respectively. While extracts of both species demonstrated a radical scavenging ability in the ABTS assay (16.12–98.02 mg TE/g), only the polar and moderately polar extracts (water, ethanol, and ethyl acetate) showed scavenging potential in the DPPH assay (4.74–16.55 mg TE/g). A reducing potential was also displayed by all extracts in the CUPRAC and FRAP assays (26.02–80.35 mg TE/g and 31.70–67.69 mg TE/g, respectively). The total antioxidant capacity of the extracts ranged from 0.24 to 2.17 mmol TE/g, and the metal chelating activity ranged from 14.74 to 33.80 mg EDTAE/g. The water extracts possessed a higher metal chelating power than the other extracts. All extracts acted as inhibitors of acetylcholinesterase (0.16–3.85 mg GALAE/g) and amylase (0.11–1.28 mmol ACAE/g). Moreover, apart from the water extracts, the other extracts also showed anti-butyrylcholinesterase activity (0.73–2.86 mg GALAE/g), as well as anti-tyrosinase (36.74–61.40 mg KAE/g) and anti-glucosidase (2.37–2.73 mmol ACAE/g) potential. In general, the water extracts were found to be weak inhibitors of the tested enzymes, while the ethanol extracts mostly showed an inhibitory effect. The obtained findings revealed the antioxidant and enzyme inhibitory properties of these two species and demonstrated that the solvent type used affected the pharmacological properties of the extracts and hence, can be useful to further investigate the active constituents yielded in the extracts and understand the mechanisms involved.