In vitro liver models combined with metabolomics approaches offer promising alternatives to animal testing in toxicology. In this study, we investigated concentration-dependent effects of hydrogen peroxide (H2O2) on the intra- and extracellular metabolome of HepG2 cells using 1H Nuclear Magnetic Resonance (NMR) spectroscopy. After cells were exposed to low, medium or high concentrations of H2O2, metabolomic analysis revealed a progressive increase in metabolic perturbation with rising toxin concentration. Significant alterations were detected in a limited subset of metabolites after low H2O2 exposure, and substantially broader disruptions occurred after medium or high H2O2 exposure, with most measured metabolites affected at the highest exposure level. To enhance metabolic competence, cells were pretreated with rifampicin to induce cytochrome P450 (CYP450) activity, which is typically low in HepG2 cells. Comparative analysis of rifampicin-pretreated and untreated cells exposed to high H2O2 concentrations demonstrated disruption of multiple biochemical pathways, including energy metabolism, lipid metabolism and amino acid metabolism. Notably, rifampicin pretreatment attenuated the magnitude of metabolic perturbations, as reflected by reduced intracellular alterations and minimal changes in extracellular metabolite profiles. Furthermore, rifampicin-treated cells exhibited metabolite signatures more consistent with human liver physiology in vivo, including increased glutathione and 2-hydroxybutyrate levels. Collectively, these findings demonstrate that pretreatment with rifampicin prior to toxin exposure enhances the physiological relevance of HepG2-based hepatotoxicity models and improves their potential to predict human liver responses. Moreover, the results highlight the sensitivity of NMR-based metabolomics to detect toxin induced metabolic changes across a range of exposure concentrations.

Polyamines are small, polycationic molecules with amino groups that are present in most living organisms. Studies indicate that polyamines increase general protein synthesis and are essential for efficient translation. While progress has been made in understanding the role of polyamines in translation in bacteria and mammals, their contribution and mode of action in plants remain largely unexplored. In a previous study, we found that putrescine (Put) and the pathogen-associated molecular pattern (PAMP) from bacterial flagellin (flg22) transcriptionally induced ribosome biogenesis in plants. Here we examined the impact of polyamines (Put and spermine, Spm) and flg22 on ribosome complex formation in Arabidopsis. Our results indicate that polyamines, flg22 and their combinations increase the abundance of actively translating polysomes. Riboproteomic analyses revealed that polyamines and flg22 trigger differential changes in the accumulation of ribosomal proteins, which are structurally confined in response to Put. Importantly, Put was found binding to non-translating and actively translating ribosomes, suggesting that this polyamine has a role in functional aspects of translation, such as stabilization and/or remodeling of polysomal complexes. Additional global proteomics analyses in polyamine biosynthesis mutants revealed that lower Put availability triggers changes in proteins associated with ribonucleoprotein complex binding and biogenesis. Overall, our findings highlight the effect of polyamines and flg22 on shaping the ribosomal protein composition of actively translating ribosomes in plants.

Plant acclimation occurs through system-wide mechanisms that include proteome shifts, some of which occur at the level of protein synthesis. All proteins are synthesized by ribosomes. Rather than being monolithic, transcript-to-protein translation machines, ribosomes can be selective and cause proteome shifts. In this study, we use apical root meristems of germinating seedlings of the monocotyledonous plant barley as a model to examine changes in protein abundance and synthesis during cold acclimation. We measured metabolic and physiological parameters that allowed us to compare protein synthesis in the cold to optimal rearing temperatures. We demonstrated that the synthesis and assembly of ribosomal proteins are independent processes in root proliferative tissue. We report the synthesis and accumulation of various macromolecular complexes and propose how ribosome compositional shifts may be associated with functional proteome changes that are part of successful cold acclimation. Our study indicates that translation initiation is limiting during cold acclimation while the ribosome population is remodelled. The distribution of the triggered ribosomal protein heterogeneity suggests that altered compositions may confer 60S subunits selective association capabilities towards translation initiation complexes. To what extent selective translation depends on heterogeneous ribo-proteome compositions in barley proliferative root tissue remains a yet unresolved question.This article is part of the discussion meeting issue 'Ribosome diversity and its impact on protein synthesis, development and disease'.

Chitosan is a natural elicitor, used for stimulating plant growth and inducing plant defense. However, due to difficulty in monitoring root growth and activity, the effects of chitosan treatment on plant root systems have been less studied as compared to plant shoot parts that include leaves, seeds, and fruits. This results in an indefinite outcome of the benefits of chitosan on plant roots. Therefore, this review aims to evaluate the effects of chitosan treatment on root growth and defense responses based on current evidence. Interestingly, many studies have demonstrated that chitosan can induce plant root defense systems, yet conversely inhibiting root growth. The effects were most clearly observed from studies using liquid or solid media as substrates, while the results from the studies using soil were inconclusive and require additional investigation to observe the effects of environmental factors. In addition, root chitosan treatment showed variable effects on shoot growth, where low chitosan concentrations tend to promote shoot growth, but high chitosan concentrations may affect shoot development. Additionally, this review discusses the potential methods of chitosan application onto plant roots. Water insolubility of chitosan is likely a major issue for root treatment. Chitosan can be dissolved in acids, but this could induce acidity stress in plant roots. Modified versions of chitosan, such as chitosan nanoparticles, carboxylated chitosan, and graft chitosan copolymers have been developed to improve solubility and functionality. Chitosan nanoparticles can also be used to encapsulate other biocontrol agents to augment biological effects on plant defense. In conclusion, root chitosan treatment could help to promote plant defense and prevent root infections, abating the uses of chemical fungicides in agriculture. However, further research is required to monitor the impact of root chitosan treatment on long-term plant growth in order to gain multifaceted information to maximize the effectiveness of root chitosan application.

We present compelling evidence for the existence of an extended innate viperin-dependent pathway, which provides crucial evidence for an adaptive response to viral agents, such as SARS-CoV-2. We show the in vivo biosynthesis of a family of novel endogenous cytosine metabolites with potential antiviral activities. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy revealed a characteristic spin-system motif, indicating the presence of an extended panel of urinary metabolites during the acute viral replication phase. Mass spectrometry additionally enabled the characterization and quantification of the most abundant serum metabolites, showing the potential diagnostic value of the compounds for viral infections. In total, we unveiled ten nucleoside (cytosine- and uracil-based) analogue structures, eight of which were previously unknown in humans allowing us to propose a new extended viperin pathway for the innate production of antiviral compounds. The molecular structures of the nucleoside analogues and their correlation with an array of serum cytokines, including IFN-α2, IFN-γ, and IL-10, suggest an association with the viperin enzyme contributing to an ancient endogenous innate immune defense mechanism against viral infection.

Ribosomes are an archetypal ribonucleoprotein assembly. Due to ribosomal evolution and function, r -proteins share specific physicochemical similarities, making the riboproteome particularly suited for tailored proteome profiling methods. Moreover, the structural proteome of ribonucleoprotein assemblies reflects context -dependent functional features. Thus, characterizing the state of riboproteomes provides insights to uncover the context -dependent functionality of r -protein rearrangements, as they relate to what has been termed the ribosomal code, a concept that parallels that of the histone code, in which chromatin rearrangements influence gene expression. Compared to highresolution ribosomal structures, omics methods lag when it comes to offering customized solutions to close the knowledge gap between structure and function that currently exists in riboproteomes. Purifying the riboproteome and subsequent shot -gun proteomics typically involves protein denaturation and digestion with proteases. The results are relative abundances of r -proteins at the ribosome population level. We have previously shown that, to gain insight into the stoichiometry of individual proteins, it is necessary to measure by proteomics bound r -proteins and normalize their intensities by the sum of r -protein abundances per ribosomal complex, i.e., 40S or 60S subunits. These calculations ensure that individual r -protein stoichiometries represent the fraction of each family/paralog relative to the complex, effectively revealing which r -proteins become substoichiometric in specific physiological scenarios. Here, we present an optimized method to profile the riboproteome of any organism as well as the synthesis rates of r -proteins determined by stable isotope -assisted mass spectrometry. Our method purifies the r -proteins in a reversibly denatured state, which offers the possibility for combined top -down and bottom -up proteomics. Our method offers a milder native denaturation of the r-proteome via a chaotropic GuHCl solution as compared with previous studies that use irreversible denaturation under highly acidic conditions to dissociate rRNA and r -proteins. As such, our method is better suited to conserve post -translational modifications (PTMs). Subsequently, our method carefully considers the amino acid composition of r -proteins to select an appropriate protease for digestion. We avoid nonspecific protease cleavage by increasing the pH of our standardized r-proteome dilutions that enter the digestion pipeline and by using a digestion buffer that ensures an optimal pH for a reliable protease digestion process. Finally, we provide the R package ProtSynthesis to study the fractional synthesis rates of r -proteins. The package uses physiological parameters as input to determine peptide or protein fractional synthesis rates. Once the physiological parameters are measured, our equations allow a fair comparison between treatments that alter the biological equilibrium state of the system under study. Our equations correct peptide enrichment using enrichments in soluble amino acids, growth rates, and total protein accumulation. As a means of validation, our pipeline fails to find "false" enrichments in non -labeled samples while also filtering out proteins with multiple unique peptides that have different enrichment values, which are rare in our datasets. These two aspects reflect the accuracy of our tool. Our method offers the possibility of elucidating individual r -protein family/paralog abundances, PTM status, fractional synthesis rates, and dynamic assembly into ribosomal complexes if top -down and bottom -up proteomic approaches are used concomitantly, taking one step further into mapping the native and dynamic status of the r-proteome onto highresolution ribosome structures. In addition, our method can be used to study the proteomes of all macromolecular assemblies that can be purified, although purification is the limiting step, and the efficacy and accuracy of the proteases may be limited depending on the digestion requirements.

The immortalised human hepatocellular HepG2 cell line is commonly used for toxicology studies as an alternative to animal testing due to its characteristic liver-distinctive functions. However, little is known about the baseline metabolic changes within these cells upon toxin exposure. We have applied 1H Nuclear Magnetic Resonance (NMR) spectroscopy to characterise the biochemical composition of HepG2 cells at baseline and post-exposure to hydrogen peroxide (H2O2). Metabolic profiles of live cells, cell extracts, and their spent media supernatants were obtained using 1H high-resolution magic angle spinning (HR-MAS) NMR and 1H NMR spectroscopic techniques. Orthogonal partial least squares discriminant analysis (O-PLS-DA) was used to characterise the metabolites that differed between the baseline and H2O2 treated groups. The results showed that H2O2 caused alterations to 10 metabolites, including acetate, glutamate, lipids, phosphocholine, and creatine in the live cells; 25 metabolites, including acetate, alanine, adenosine diphosphate (ADP), aspartate, citrate, creatine, glucose, glutamine, glutathione, and lactate in the cell extracts, and 22 metabolites, including acetate, alanine, formate, glucose, pyruvate, phenylalanine, threonine, tryptophan, tyrosine, and valine in the cell supernatants. At least 10 biochemical pathways associated with these metabolites were disrupted upon toxin exposure, including those involved in energy, lipid, and amino acid metabolism. Our findings illustrate the ability of NMR-based metabolic profiling of immortalised human cells to detect metabolic effects on central metabolism due to toxin exposure. The established data sets will enable more subtle biochemical changes in the HepG2 model cell system to be identified in future toxicity testing.

Sarcoidosis embodies a complex inflammatory disorder spanning multiple systems, with its origin remaining elusive. It manifests as the infiltration of inflammatory cells that coalesce into distinctive noncaseous granulomas within afflicted organs. Unraveling this disease necessitates the utilization of cellular or tissue-based imaging methods to both visualize and characterize the biochemistry of these sarcoid granulomas. Although hematoxylin and eosin stain, standard in routine use alongside cytological stains have found utility in diagnosis within clinical contexts, special stains such as Masson's trichrome, reticulin, methenamine silver, and Ziehl-Neelsen provide additional varied perspectives of sarcoid granuloma imaging. Immunohistochemistry aids in pinpointing specific proteins and gene expressions further characterizing these granulomas. Finally, recent advances in spatial transcriptomics promise to divulge profound insights into their spatial orientation and three-dimensional (3-D) molecular mapping. This review focuses on a range of preexisting imaging methods employed for visualizing sarcoid granulomas at the cellular level while also exploring the potential of the latest cutting-edge approaches like spatial transcriptomics and matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), with the overarching goal of shedding light on the trajectory of sarcoidosis research.

Inulin, a polysaccharide characterized by a β-2,1 fructosyl-fructose structure terminating in a glucosyl moiety, is naturally present in plant roots and tubers. Current methods provide average degrees of polymerization (DP) but lack information on the distribution and absolute concentration of each DP. To address this limitation, a reproducible (CV < 10 %) high throughput (<2 min/sample) MALDI-MRMS approach capable of characterizing and quantifying inulin molecules in plants using matched-matrix consisting of α-cyano-4-hydroxycinnamic acid butylamine salt (CHCA-BA), chicory inulin-12C and inulin-13C was developed. The method identified variation in chain lengths and concentration of inulin across various plant species. Globe artichoke hearts, yacón and elephant garlic yielded similar concentrations at 15.6 g/100 g dry weight (DW), 16.8 g/100 g DW and 17.7 g/100 g DW, respectively, for DP range between 9 and 22. In contrast, Jerusalem artichoke demonstrated the highest concentration (53.4 g/100 g DW) within the same DP ranges. Jerusalem artichoke (DPs 9-32) and globe artichoke (DPs 9-36) showed similar DP distributions, while yacón and elephant garlic displayed the narrowest and broadest DP ranges (DPs 9-19 and DPs 9-45, respectively). Additionally, qualitative measurement for all inulin across all plant samples was feasible using the peak intensities normalized to Inulin-13C, and showed that the ratio of yacón, elephant garlic and Jerusalem was approximately one, two and three times that of globe artichoke. This MALDI-MRMS approach provides comprehensive insights into the structure of inulin molecules, opening avenues for in-depth investigations into how DP and concentration of inulin influence gut health and the modulation of noncommunicable diseases, as well as shedding light on refining cultivation practices to elevate the beneficial health properties associated with specific DPs.

Increases in soil salinity impact growth and agricultural yield by inhibiting plant functions. Interactions of fungal endophytes with crop plants can improve tolerance and is a less expensive approach. Here, the role of Trichoderma harzianum T-22 in alleviating NaCl-induced stress in two barley genotypes (cv. Vlamingh and cv. Gairdner) has been investigated. Metabolomics using GC-MS for polar metabolites and LC-MS for lipids was employed to provide insights into the biochemical changes in inoculated roots during the early stages of interaction. T. harzianum improved root growth of both genotypes in saline conditions whereas uninoculated roots were significantly shorter after salt treatment. The fungus reduced relative concentration of sugars in both genotypes under saline conditions but there was no change in organic acids. Amino acids decreased only in cv. Gairdner in fungus-inoculated roots under saline conditions. Lipid analysis suggested that salt stress causes large changes in roots but that inoculation with fungus greatly reduces the extent of these changes. By studying a tolerant and a sensitive genotype and their responses to salt and inoculation we have been able to develop hypotheses that explain the tolerance of Vlamingh to salt and how fungal inoculation changes the response of Gairdner to improve its tolerance.

We present compelling evidence for the existence of an extended innate viperin dependent pathway which provides crucial evidence for an adaptive response to viral agents like SARS-CoV-2. We show the in vivo biosynthesis of a family of endogenous cytosine metabolites with potential antiviral activity. Two dimensional Nuclear magnetic resonance (NMR) spectroscopy revealed a characteristic spin-system motif indicating the presence of an extended panel of urinary metabolites during the acute viral replication phase. Mass spectrometry additionally allowed the characterization and quantification of the most abundant serum metabolites showing potential diagnostic value of the compounds for viral infections. In total, we unveiled ten nucleoside (cytosine and uracil based) analogue structures, eight of which were previously unknown in humans. The molecular structures of the nucleoside analogues and their correlation with an array of serum cytokines, including IFN-α2, IFN-γ and IL-10, suggest an association with the viperin enzyme contributing to an endogenous innate immune defence mechanism against viral infection. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement We thank The Spinnaker Health Research Foundation, WA, The McCusker Foundation, WA, The Western Australian State Government and the Medical Research Future Fund (EPCD000037 and MRF2014349) for financial support. We thank the Department of Jobs, Tourism, Science and Innovation, Government of a Western Australian Premier's Fellowship for RLL and the ARC for Laureate Fellowship funding for EH. JW thanks Ministerio de Ciencia, Tecnología e Innovación (Minciencias), Ministerio de Educación Nacional, Ministerio de Industria, Comercio y Turismo e ICETEX (792-2017) 2a Convocatoria Ecosistema Científico - Colombia Científica para la Financiación de Proyectos de I + D + i), World Bank and Vicerrectoría de Investigaciones, Pontificia Universidad Javeriana, Bogotá, Colombia (contract no. FP44842 - 221-2018). We gratefully thank the Werner Siemens Imaging Center under direction of Prof. Bernd Pichler for supporting this project as well as Aditi Kulkarni and Daniele Bucci for excellent technical assistance. JMW, GBE and LDH thank the New Zealand Ministry of Business Innovation & Employment for support (Endeavour Fund program contract UOOX1904 (NZ)). JKN and JW acknowledge Dr. Oscar Millet for pertinent discussions. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The usage of all samples and data was approved by the Ethics Commission of Heidelberg Medical University (S-324/2020) and the Human Research Ethics Committee (HREC) of Murdoch University (Approval 2020/053, and Approval 2021/049). All participants signed a written informed consent according to the declaration of Helsinki. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors. Some data are available online at:

SUMMARY Skeletal muscle contains a resident population of somatic stem cells capable of both self-renewal and differentiation. The signals that regulate this important decision have yet to be fully elucidated. Here we use metabolomics and mass spectrometry imaging (MSI) to identity a state of localized hyperglycaemia following skeletal muscle injury. We show that committed muscle progenitor cells exhibit an enrichment of glycolytic and TCA cycle genes and that extracellular monosaccharide availability regulates intracellular citrate levels and global histone acetylation. Muscle stem cells exposed to a reduced (or altered) monosaccharide environment demonstrate reduced global histone acetylation and transcription of myogenic determination factors (including myod1 ). Importantly, reduced monosaccharide availability was linked directly to increased rates of asymmetric division and muscle stem cell self-renewal in regenerating skeletal muscle. Our results reveal an important role for the extracellular metabolic environment in the decision to undergo self-renewal or myogenic commitment during skeletal muscle regeneration.

In Huntington's disease (HD), a key pathological feature includes the development of inclusion-bodies of fragments of the mutant huntingtin protein in the neurons of the striatum and hippocampus. To examine the molecular changes associated with inclusion-body formation, we applied MALDI-mass spectrometry imaging and deuterium pulse labelling to determine lipid levels and synthesis rates in the hippocampus of a transgenic mouse model of HD (R6/1 line). The R6/1 HD mice lacked inclusions in the hippocampus at 6 weeks of age (pre-symptomatic), whereas inclusions were pervasive by 16 weeks of age (symptomatic). Hippocampal subfields (CA1, CA3 and DG), which formed the highest density of inclusion formation in the mouse brain showed a reduction in the relative abundance of neuron-enriched lipids that have roles in neurotransmission, synaptic plasticity, neurogenesis, and ER-stress protection. Lipids involved in the adaptive response to ER stress (phosphatidylinositol, phosphatidic acid, and ganglioside classes) displayed increased rates of synthesis in HD mice relative to WT mice at all the ages examined, including prior to the formation of the inclusion bodies. Our findings, therefore, support a role for ER stress occurring pre-symptomatically and potentially contributing to pathological mechanisms underlying HD.

Floral chemical defence strategies remain under-investigated, despite the significance of flowers to plant fitness. We used cyanogenic glycosides (CNglycs)—constitutive secondary metabolites that deter herbivores by releasing hydrogen cyanide, but also play other metabolic roles—to ask whether more apparent floral tissues and those most important for fitness are more defended as predicted by optimal defence theories, and what fine-scale CNglyc localisation reveals about function(s)? Florets of eleven species from the Proteaceae family were dissected to quantitatively compare the distribution of CNglycs within flowers and investigate whether distributions vary with other floral/plant traits. CNglycs were identified and their localisation in florets was revealed by matrix-assisted laser desorption ionisation mass spectrometry imaging (MALDI-MSI). We identified extremely high CNglyc content in floral tissues of several species (>1% CN), highly tissue-specific CNglyc distributions within florets, and substantial interspecific differences in content distributions, not all consistent with optimal defence hypotheses. Four patterns of within-flower CNglyc allocation were identified: greater tissue-specific allocations to (1) anthers, (2) pedicel (and gynophore), (3) pollen presenter, and (4) a more even distribution among tissues with higher content in pistils. Allocation patterns were not correlated with other floral traits (e.g. colour) or taxonomic relatedness. MALDI-MSI identified differential localisation of two tyrosine-derived CNglycs, demonstrating the importance of visualising metabolite localisation, with the diglycoside proteacin in vascular tissues, and monoglycoside dhurrin across floral tissues. High CNglyc content, and diverse, specific within-flower localisations indicate allocations are adaptive, highlighting the importance of further research into the ecological and metabolic roles of floral CNglycs.

Fungal pathogens pose a major threat to Cannabis sativa production, requiring safe and effective management procedures to control disease. Chitin and chitosan are natural molecules that elicit plant defense responses. Investigation of their effects on C. sativa will advance understanding of plant responses towards elicitors and provide a potential pathway to enhance plant resistance against diseases. Plants were grown in the in vitro Root-TRAPR system and treated with colloidal chitin and chitosan. Plant morphology was monitored, then plant tissues and exudates were collected for enzymatic activity assays, phytohormone quantification, qPCR analysis and proteomics profiling. Chitosan treatments showed increased total chitinase activity and expression of pathogenesis-related (PR) genes by 3-5 times in the root tissues. In the exudates, total peroxidase and chitinase activities and levels of defense proteins such as PR protein 1 and endochitinase 2 were increased. Shoot development was unaffected, but root development was inhibited after chitosan exposure. In contrast, chitin treatments had no significant impact on any defense parameters, including enzymatic activities, hormone quantities, gene expression levels and root secreted proteins. These results indicate that colloidal chitosan, significantly enhancing defense responses in C. sativa root system, could be used as a potential elicitor, particularly in hydroponic scenarios to manage crop diseases.

Abstract Southern blight disease, caused by the fungal pathogen Athelia rolfsii, suppresses plant growth and reduces product yield in Cannabis sativa agriculture. Mechanisms of pathology of this soil‐borne disease remain poorly understood, with disease management strategies reliant upon broad‐spectrum antifungal use. Exposure to chitosan, a natural elicitor, has been proposed as an alternative method to control diverse fungal diseases in an eco‐friendly manner. In this study, C. sativa plants were grown in the Root‐TRAPR system, a transparent hydroponic growth device, where plant roots were primed with .2% colloidal chitosan prior to A. rolfsii inoculation. Both chitosan‐primed and unprimed inoculated plants displayed classical symptoms of wilting and yellowish leaves, indicating successful infection. Non‐primed infected plants showed increased shoot defense responses with doubling of peroxidase and chitinase activities. The levels of growth and defense hormones including auxin, cytokinin, and jasmonic acid were increased 2–5‐fold. In chitosan‐primed infected plants, shoot peroxidase activity and phytohormone levels were decreased 1.5–4‐fold relative to the unprimed infected plants. When compared with shoots, roots were less impacted by A. rolfsii infection, but the pathogen secreted cell wall‐degrading enzymes into the root‐growth solution. Chitosan priming inhibited root growth, with root lengths of chitosan‐primed plants approximately 65% shorter than the control, but activated root defense responses, with root peroxidase activity increased 2.7‐fold along with increased secretion of defense proteins. The results suggest that chitosan could be an alternative platform to manage southern blight disease in C. sativa cultivation; however, further optimization is required to maximize effectiveness of chitosan.

This study explores the sphingolipid class of oligohexosylceramides (OHCs), a rarely studied group, in barley ( Hordeum vulgare L.) through a new lipidomics approach. Profiling identified 45 OHCs in barley ( Hordeum vulgare L.), elucidating their fatty acid (FA), long-chain base (LCB) and sugar residue compositions; and was accomplished by monophasic extraction followed by reverse-phased high performance liquid chromatography electrospray ionisation quadrupole-time-of-flight tandem mass spectrometry (HPLC–ESI–QqTOF–MS/MS) employing parallel reaction monitoring (PRM). Results revealed unknown ceramide species and highlighted distinctive FA and LCB compositions when compared to other sphingolipid classes. Structurally, the OHCs featured predominantly trihydroxy LCBs associated with hydroxylated FAs and oligohexosyl residues consisting of two–five glucose units in a linear 1 → 4 linkage. A survey found OHCs in tissues of major cereal crops while noting their absence in conventional dicot model plants. This study found salinity stress had only minor effects on the OHC profile in barley roots, leaving questions about their precise functions in plant biology unanswered.

Background Influenza A virus (IAV) is the only influenza virus causing flu pandemics (i.e., global epidemics of flu disease). Influenza (the flu) is a highly contagious disease that can be deadly, especially in high-risk groups. Worldwide, these annual epidemics are estimated to result in about 3 to 5 million cases of severe illness and in about 290,000 to 650,000 respiratory deaths. We intend to reveal the effect of IAV infection on the host′s metabolism, immune response, and neurotoxicity by using a mouse IAV infection model. Methods 51 metabolites of murine blood plasma (33 amino acids/amino acid derivatives (AADs) and 18 metabolites of the tryptophan pathway) were analyzed by using Ultra-High-Performance Liquid Chromatography-Mass Spectrometry with Electrospray Ionization at the acute (7 days post-infection (dpi)), resolution (14 dpi), and recovery (21 dpi) stages of the virus infection in comparison with controls. Results Among the 33 biogenic amino acids/AADs, the levels of five amino acids/AADs (1-methylhistidine, 5-oxoproline, α-aminobutyric acid, glutamine, and taurine) increased by 7 dpi, whereas the levels of ten amino acids/AADs (4-hydroxyproline, alanine, arginine, asparagine, cysteine, citrulline, glycine, methionine, proline, and tyrosine) decreased. By 14 dpi, the levels of one AAD (3-methylhistidine) increased, whereas the levels of five amino acids/AADs (α-aminobutyric acid, aminoadipic acid, methionine, threonine, valine) decreased. Among the 18 metabolites from the tryptophan pathway, the levels of kynurenine, quinolinic acid, hydroxykynurenine increased by 7 dpi, whereas the levels of indole-3-acetic acid and nicotinamide riboside decreased. Conclusions Our data may facilitate understanding the molecular mechanisms of host responses to IAV infection and provide a basis for discovering potential new mechanistic, diagnostic, and prognostic biomarkers and therapeutic targets for IAV infection.