Induced responses to the wheat pathogen: Tan Spot-(Pyrenophora tritici-repentis) in wheat (Triticum aestivum) focus on changes in defence associated and sugar metabolism.

INTRODUCTION: Tan Spot (TS) disease of wheat is caused by Pyrenophora tritici-repentis (Ptr), where most of the yield loss is linked to diseased flag leaves. As there are no fully resistant cultivars available, elucidating the responses of wheat to Ptr could inform the derivation of new resistant genotypes. OBJECTIVES: The study aimed to characterise the flag-leaf metabolomes of two spring wheat cultivars (Triticum aestivum L. cv. PF 080719 [PF] and cv. Fundacep Horizonte [FH]) following challenge with Ptr to gain insights into TS disease development. METHODS: PF and FH plants were inoculated with a Ptr strain that produces the necrotrophic toxin ToxA. The metabolic changes in flag leaves following challenge (24, 48, 72, and 96 h post-inoculation [hpi]) with Ptr were investigated using untargeted flow infusion ionisation-high resolution mass spectroscopy (FIE-HRMS). RESULTS: Both cultivars were susceptible to Ptr at the flag-leaf stage. Comparisons of Ptr- and mock-inoculated plants indicated that a major metabolic shift occurred at 24 hpi in FH, and at 48 hpi in PF. Although most altered metabolites were genotype specific, they were linked to common pathways; phenylpropanoid and flavonoid metabolism. Alterations in sugar metabolism as well as in glycolysis and glucogenesis pathways were also observed. Pathway enrichment analysis suggested that Ptr-triggered alterations in chloroplast and photosynthetic machinery in both cultivars, especially in FH at 96 hpi. In a wheat-Ptr interactome in integrative network analysis, "flavone and flavonol biosynthesis" and "starch and sucrose metabolism" were targeted as the key metabolic processes underlying PF-FH-Ptr interactions. CONCLUSION: These observations suggest the potential importance of flavone and flavonol biosynthesis as well as bioenergetic shifts in susceptibility to Ptr. This work highlights the value of metabolomic approaches to provide novel insights into wheat pathosystems.

Metabolomics targets tissue-specific responses in alleviating the negative effects of salinity in tef (Eragrostis tef) during germination.

MAIN CONCLUSION: Salinity induced metabolite responses resulted in differential accumulation of flavonoids and antioxidant metabolites in shoots and roots suggesting improved antioxidant capacity in providing salt-adaptive phenotype of tef seedling. Tef [(Eragrostis tef) (Zucc.) Trotter] is an important 'cash crop' of Ethiopia grown mainly for human food, and development of elite tef cultivars with better performance is vital to Ethiopian farmers and breeders. Soil salinity is one of the key constraints that affects tef yield in the Ethiopian lowlands and Rift valley where cultivation of tef is limited. Being a minor crop, the responses of tef towards salinity is unknown. Salinity involves physiological and metabolite reprogramming that can have major impact on germination and seedling establishment. Here we evaluate the in vitro effect of NaCl on tef germination and associate this with metabolomic approaches to suggest salt tolerance mechanisms. In this study, 19 tef varieties were screened for NaCl tolerance and were investigated using untargeted metabolomics. Screened tef varieties showed differential germination rates with NaCl treatment varying from < 20 to 100%. Viable seedlings exposed to NaCl exhibited purple-red pigment accumulation in the roots except for Beten and Tullu nasy varieties. Metabolite comparisons between shoots and roots showed significant differences and, in particular, roots of salt tolerant tef varieties accumulated flavonoid derivatives as well as sugars and cell wall associated metabolites. These metabolic changes were correlated with patterns of antioxidant capacities and total flavonoid content in shoots and roots and suggested a mitigating response by tef to salinity. Our study highlights the role of flavonoid accumulation following salt stress on tef seedlings and further these findings could be used as targets for selective tef breeding.

Vitamin D status modulates innate immune responses and metabolomic profiles following acute prolonged cycling.

PURPOSE: The influence of vitamin D status on exercise-induced immune dysfunction remains unclear. The aim of this study was to investigate the effects of vitamin D status (circulating 25(OH)D) on innate immune responses and metabolomic profiles to prolonged exercise. METHODS: Twenty three healthy, recreationally active males (age 25 ± 7 years; maximal oxygen uptake [[Formula: see text]max] 56 ± 9 mL·kg-1·min-1), classified as being deficient (n = 7) or non-deficient n = 16) according to plasma concentrations of 25(OH)D, completed 2.5 h of cycling at 15% Δ (~ 55-60% [Formula: see text]max). Venous blood and unstimulated saliva samples were obtained before and after exercise. RESULTS: Participants with deficient plasma 25(OH)D on average had lower total lymphocyte count (mean difference [95% confidence interval], 0.5 cells × 109 L [0.1, 0.9]), p = 0.013) and greater neutrophil:lymphocyte ratio (1.3 cells × 109 L, [0.1, 2.5], p = 0.033). The deficient group experienced reductions from pre-exercise to 1 h post-exercise (- 43% [- 70, - 15], p = 0.003) in bacterial stimulated elastase in blood neutrophils compared to non-deficient participants (1% [- 20, 21], p = 1.000) Multivariate analyses of plasma metabolomic profiles showed a clear separation of participants according to vitamin D status. Prominent sources of variation between groups were purine/pyrimidine catabolites, inflammatory markers (linoleic acid pathway), lactate and tyrosine/adrenaline. CONCLUSION: These findings provide evidence of the influence of vitamin D status on exercise-induced changes in parameters of innate immune defence and metabolomic signatures such as markers of inflammation and metabolic stress.

Molecular and physiological responses to desiccation indicate the abscisic acid pathway is conserved in the peat moss, Sphagnum.

Mosses of the genus Sphagnum are the main components of peatlands, a major carbon-storing ecosystem. Changes in precipitation patterns are predicted to affect water relations in this ecosystem, but the effect of desiccation on the physiological and molecular processes in Sphagnum is still largely unexplored. Here we show that different Sphagnum species have differential physiological and molecular responses to desiccation but, surprisingly, this is not directly correlated with their position in relation to the water table. In addition, the expression of drought responsive genes is increased upon water withdrawal in all species. This increase in gene expression is accompanied by an increase in abscisic acid (ABA), supporting a role for ABA during desiccation responses in Sphagnum. Not only do ABA levels increase upon desiccation, but Sphagnum plants pre-treated with ABA display increased tolerance to desiccation, suggesting that ABA levels play a functional role in the response. In addition, many of the ABA signalling components are present in Sphagnum and we demonstrate, by complementation in Physcomitrium patens, that Sphagnum ABI3 is functionally conserved. The data presented here, therefore, support a conserved role for ABA in desiccation responses in Sphagnum.

Spectral binning as an approach to post-acquisition processing of high resolution FIE-MS metabolome fingerprinting data.

INTRODUCTION: Flow infusion electrospray high resolution mass spectrometry (FIE-HRMS) fingerprinting produces complex, high dimensional data sets which require specialist in-silico software tools to process the data prior to analysis. OBJECTIVES: Present spectral binning as a pragmatic approach to post-acquisition procession of FIE-HRMS metabolome fingerprinting data. METHODS: A spectral binning approach was developed that included the elimination of single scan m/z events, the binning of spectra and the averaging of spectra across the infusion profile. The modal accurate m/z was then extracted for each bin. This approach was assessed using four different biological matrices and a mix of 31 known chemical standards analysed by FIE-HRMS using an Exactive Orbitrap. Bin purity and centrality metrics were developed to objectively assess the distribution and position of accurate m/z within an individual bin respectively. RESULTS: The optimal spectral binning width was found to be 0.01 amu. 80.8% of the extracted accurate m/z matched to predicted ionisation products of the chemical standards mix were found to have an error of below 3 ppm. The open-source R package binneR was developed as a user friendly implementation of the approach. This was able to process 100 data files using 4 Central Processing Units (CPU) workers in only 55 seconds with a maximum memory usage of 1.36 GB. CONCLUSION: Spectral binning is a fast and robust method for the post-acquisition processing of FIE-HRMS data. The open-source R package binneR allows users to efficiently process data from FIE-HRMS experiments with the resources available on a standard desktop computer.

Metabotyping the Welsh population of badgers based on thoracic fluid.

INTRODUCTION: The European badger (Meles meles) is a known wildlife reservoir for bovine tuberculosis (bTB) and a better understanding of the epidemiology of bTB in this wildlife species is required for disease control in both wild and farmed animals. Flow infusion electrospray-high-resolution mass spectrometry (FIE-HRMS) may potentially identify novel metabolite biomarkers based on which new, rapid, and sensitive point of care tests for bTB infection could be developed. OBJECTIVES: In this foundational study, we engaged on assessing the baseline metabolomic variation in the non-bTB infected badger population ("metabotyping") across Wales. METHODS: FIE-HRMS was applied on thoracic fluid samples obtained by post-mortem of bTB negative badgers (n = 285) which were part of the Welsh Government 'All Wales Badger Found Dead' study. RESULTS: Using principal component analysis and partial least squares-discriminant analyses, the major sources of variation were linked to sex, and to a much lesser extent age, as indicated by tooth wear. Within the female population, variation was seen between lactating and non-lactating individuals. No significant variation linked to the presence of bite wounds, obvious lymphatic lesions or geographical region of origin was observed. CONCLUSION: Future metabolomic work when making comparisons between bTB infected and non-infected badger samples will only need be sex-matched and could focus on males only, to avoid lactation bias.

Untargeted metabolomic analysis of thoracic blood from badgers indicate changes linked to infection with bovine tuberculosis (Mycobacterium bovis): a pilot study.

INTRODUCTION: Mycobacterium bovis, the causative agent of bovine tuberculosis (bTB) in cattle, represents a major disease burden to UK cattle farming, with considerable costs associated with its control. The European badger (Meles meles) is a known wildlife reservoir for bTB and better knowledge of the epidemiology of bTB through testing wildlife is required for disease control. Current tests available for the diagnosis of bTB in badgers are limited by cost, processing time or sensitivities. MATERIALS AND METHODS: We assessed the ability of flow infusion electrospray-high-resolution mass spectrometry (FIE-HRMS) to determine potential differences between infected and non-infected badgers based on thoracic blood samples obtained from badgers found dead in Wales. Thoracic blood samples were autoclaved for handling in a containment level 2 (CL2) hazard laboratory. RESULTS: Here we show the major differences associated with with M. bovis infection were changes to folate, pyrimidine, histidine, glycerophospholipid and phosphonate metabolism. CONCLUSIONS: Our studies have indicated differences in the metabolomic signature of badgers found dead in relation to their infection status, suggesting metabolomics could hold potential for developing novel diagnostics for bTB in badgers. As well as highlighting a potential way to handle samples containing a highly pathogenic agent at CL2 for metabolomics studies.

Metabolomic changes in Mycobacterium avium subsp. paratuberculosis (MAP) challenged Holstein-Friesian cattle highlight the role of serum amino acids as indicators of immune system activation.

INTRODUCTION: Paratuberculosis, commonly known as Johne's disease, is a chronic granulomatous infection of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). Clinical signs, including reduced milk yields, weight loss and diarrhoea, are typically absent until 2 to 6 years post exposure. OBJECTIVES: To identify metabolomic changes profiles of MAP challenged Holstein-Friesian (HF) cattle and correlate identified metabolites to haematological and immunological parameters. METHODS: At approximately 6 weeks of age, calves (n = 9) were challenged with 3.8 × 109 cells of MAP (clinical isolate CIT003) on 2 consecutive days. Additional unchallenged calves (n = 9) formed the control group. The study used biobanked serum from cattle sampled periodically from 3- to 33-months post challenge. The assessment of sera using flow infusion electrospray high resolution mass spectrometry (FIE-HRMS) for high throughput, sensitive, non-targeted metabolite fingerprinting highlighted differences in metabolite levels between the two groups. RESULTS: In total, 25 metabolites which were differentially accumulated in MAP challenged cattle were identified, including 20 which displayed correlation to haematology parameters, particularly monocyte levels. CONCLUSION: The targeted metabolites suggest shifts in amino acid metabolism that could reflect immune system activation linked to MAP and as well as differences in phosphocholine levels which could reflect activation of the Th1 (tending towards pro-inflammatory) immune response. If verified by future work, selected metabolites could be used as biomarkers to diagnose and manage MAP infected cattle.

Metabolomic changes in polyunsaturated fatty acids and eicosanoids as diagnostic biomarkers in Mycobacterium avium ssp. paratuberculosis (MAP)-inoculated Holstein-Friesian heifers.

Mycobacterium avium subspecies paratuberculosis (MAP) is the causative organism of Johne's disease, a chronic granulomatous enteritis of ruminants. We have previously used naturally MAP-infected heifer calves to document metabolomic changes occurring in MAP infections. Herein, we used experimentally MAP-inoculated heifer calves to identify biomarkers for MAP infections. At 2-weeks of age, 20 Holstein-Friesian (HF) calves were experimentally inoculated with MAP. These calves, along with 20 control calves, were sampled biweekly up to 13-months of age and then monthly up to 19-months of age. Sera were assessed using flow infusion electrospray high-resolution mass spectrometry (FIE-HRMS) on a Q Exactive hybrid quadrupole-Orbitrap mass spectrometer for high throughput, sensitive, non-targeted metabolite fingerprinting. Partial least squares-discriminate analysis (PLS-DA) and hierarchical cluster analysis (HCA) discriminated between MAP-inoculated and control heifer calves. Out of 34 identified metabolites, six fatty acyls were able to differentiate between experimental groups throughout the study, including 8, 11, 14-eicosatrienoic acid and cis-8, 11, 14, 17-eicosatetraenoic acid which were also detected in our previous study and so further suggested their value as biomarkers for MAP infection. Pathway analysis highlighted the role of the alpha-linoleic acid and linoleic acid metabolism. Within these pathways, two broad types of response, with a rapid increase in some saturated fatty acids and some n-3 polyunsaturated fatty acids (PUFAs) and later n-6 PUFAs, became predominant. This could indicate an initial anti-inflammatory colonisation phase, followed by an inflammatory phase. This study demonstrates the validity of the metabolomic approach in studying MAP infections. Nevertheless, further work is required to define further key events, particularly at a cell-specific level.

FluoroMatch 2.0-making automated and comprehensive non-targeted PFAS annotation a reality.

Because of the pervasiveness, persistence, and toxicity of per- and polyfluoroalkyl substances (PFAS), there is growing concern over PFAS contamination, exposures, and health effects. The diversity of potential PFAS is astounding, with nearly 10,000 PFAS catalogued in databases to date (and growing). The ability to detect the thousands of known PFAS, and discover previously uncatalogued PFAS, is necessary to understand the scope of PFAS contamination and to identify appropriate remediation and regulatory solutions. Current non-targeted methods for PFAS analysis require manual curation and are time-consuming, prone to error, and not comprehensive. FluoroMatch Flow 2.0 is the first software to cover all steps of data processing for PFAS discovery in liquid chromatography-high-resolution tandem mass spectrometry samples. These steps include feature detection, feature blank filtering, exact mass matching to catalogued PFAS, mass defect filtering, homologous series detection, retention time pattern analysis, class-based MS/MS screening, fragment screening, and predicted MS/MS from SMILES structures. In addition, a comprehensive confidence level criterion is implemented to help users understand annotation certainty and integrate various layers of evidence to reduce overreporting. Applying the software to aqueous film forming foam analysis, we discovered over one thousand likely PFAS including previously unreported species. Furthermore, we were able to filter out 96% of features which were likely not PFAS. FluoroMatch Flow 2 increased coverage of likely PFAS by over tenfold compared to the previous release. This software will enable researchers to better characterize PFAS in the environment and in biological systems.

Non-Targeted Metabolite Profiling Reveals Host Metabolomic Reprogramming during the Interaction of Black Pepper with Phytophthora capsici.

Phytophthora capsici is one of the most destructive pathogens causing quick wilt (foot rot) disease in black pepper (Piper nigrum L.) to which no effective resistance has been defined. To better understand the P. nigrum-P. capsici pathosystem, we employed metabolomic approaches based on flow-infusion electrospray-high-resolution mass spectrometry. Changes in the leaf metabolome were assessed in infected and systemic tissues at 24 and 48 hpi. Principal Component Analysis of the derived data indicated that the infected leaves showed a rapid metabolic response by 24 hpi whereas the systemic leaves took 48 hpi to respond to the infection. The major sources of variations between infected leaf and systemic leaf were identified, and enrichment pathway analysis indicated, major shifts in amino acid, tricarboxylic acid cycle, nucleotide and vitamin B6 metabolism upon infection. Moreover, the individual metabolites involved in defensive phytohormone signalling were identified. RT-qPCR analysis of key salicylate and jasmonate biosynthetic genes indicated a transient reduction of expression at 24 hpi but this increased subsequently. Exogenous application of jasmonate and salicylate reduced P. capsici disease symptoms, but this effect was suppressed with the co-application of abscisic acid. The results are consistent with abscisic acid reprogramming, salicylate and jasmonate defences in infected leaves to facilitate the formation of disease. The augmentation of salicylate and jasmonate defences could represent an approach through which quick wilt disease could be controlled in black pepper.

Developing community-based urine sampling methods to deploy biomarker technology for the assessment of dietary exposure.

OBJECTIVE: Obtaining objective, dietary exposure information from individuals is challenging because of the complexity of food consumption patterns and the limitations of self-reporting tools (e.g., FFQ and diet diaries). This hinders research efforts to associate intakes of specific foods or eating patterns with population health outcomes. DESIGN: Dietary exposure can be assessed by the measurement of food-derived chemicals in urine samples. We aimed to develop methodologies for urine collection that minimised impact on the day-to-day activities of participants but also yielded samples that were data-rich in terms of targeted biomarker measurements. SETTING: Urine collection methodologies were developed within home settings. PARTICIPANTS: Different cohorts of free-living volunteers. RESULTS: Home collection of urine samples using vacuum transfer technology was deemed highly acceptable by volunteers. Statistical analysis of both metabolome and selected dietary exposure biomarkers in spot urine collected and stored using this method showed that they were compositionally similar to urine collected using a standard method with immediate sample freezing. Even without chemical preservatives, samples can be stored under different temperature regimes without any significant impact on the overall urine composition or concentration of forty-six exemplar dietary exposure biomarkers. Importantly, the samples could be posted directly to analytical facilities, without the need for refrigerated transport and involvement of clinical professionals. CONCLUSIONS: This urine sampling methodology appears to be suitable for routine use and may provide a scalable, cost-effective means to collect urine samples and to assess diet in epidemiological studies.

Spot and Cumulative Urine Samples Are Suitable Replacements for 24-Hour Urine Collections for Objective Measures of Dietary Exposure in Adults Using Metabolite Biomarkers.

BACKGROUND: Measurement of multiple food intake exposure biomarkers in urine may offer an objective method for monitoring diet. The potential of spot and cumulative urine samples that have reduced burden on participants as replacements for 24-h urine collections has not been evaluated. OBJECTIVE: The aim of this study was to determine the utility of spot and cumulative urine samples for classifying the metabolic profiles of people according to dietary intake when compared with 24-h urine collections in a controlled dietary intervention study. METHODS: Nineteen healthy individuals (10 male, 9 female, aged 21-65 y, BMI 20-35 kg/m2) each consumed 4 distinctly different diets, each for 1 wk. Spot urine samples were collected ∼2 h post meals on 3 intervention days/wk. Cumulative urine samples were collected daily over 3 separate temporal periods. A 24-h urine collection was created by combining the 3 cumulative urine samples. Urine samples were analyzed with metabolite fingerprinting by both high-resolution flow infusion electrospray mass spectrometry (FIE-HRMS) and proton nuclear magnetic resonance spectroscopy (1H-NMR). Concentrations of dietary intake biomarkers were measured with liquid chromatography triple quadrupole mass spectrometry and by integration of 1H-NMR data. RESULTS: Cross-validation modeling with 1H-NMR and FIE-HRMS data demonstrated the power of spot and cumulative urine samples in predicting dietary patterns in 24-h urine collections. Particularly, there was no significant loss of information when post-dinner (PD) spot or overnight cumulative samples were substituted for 24-h urine collections (classification accuracies of 0.891 and 0.938, respectively). Quantitative analysis of urine samples also demonstrated the relation between PD spot samples and 24-h urines for dietary exposure biomarkers. CONCLUSIONS: We conclude that PD spot urine samples are suitable replacements for 24-h urine collections. Alternatively, cumulative samples collected overnight predict similarly to 24-h urine samples and have a lower collection burden for participants.

Diversity and association of phenotypic and metabolomic traits in the close model grasses Brachypodium distachyon, B. stacei and B. hybridum.

Background and Aims: Morphological traits in combination with metabolite fingerprinting were used to investigate inter- and intraspecies diversity within the model annual grasses Brachypodium distachyon, Brachypodium stacei and Brachypodium hybridum . Methods: Phenotypic variation of 15 morphological characters and 2219 nominal mass ( m / z ) signals generated using flow infusion electrospray ionization-mass spectrometry (FIE-MS) were evaluated in individuals from a total of 174 wild populations and six inbred lines, and 12 lines, of the three species, respectively. Basic statistics and multivariate principal component analysis and discriminant analysis were used to differentiate inter- and intraspecific variability of the two types of variable, and their association was assayed with the rcorr function. Key Results: Basic statistics and analysis of variance detected eight phenotypic characters [(stomata) leaf guard cell length, pollen grain length, (plant) height, second leaf width, inflorescence length, number of spikelets per inflorescence, lemma length, awn length] and 434 tentatively annotated metabolite signals that significantly discriminated the three species. Three phenotypic traits (pollen grain length, spikelet length, number of flowers per inflorescence) might be genetically fixed. The three species showed different metabolomic profiles. Discriminant analysis significantly discriminated the three taxa with both morphometric and metabolome traits and the intraspecific phenotypic diversity within B. distachyon and B. stacei . The populations of B. hybridum were considerably less differentiated. Conclusions: Highly explanatory metabolite signals together with morphological characters revealed concordant patterns of differentiation of the three taxa. Intraspecific phenotypic diversity was observed between northern and southern Iberian populations of B. distachyon and between eastern Mediterranean/south-western Asian and western Mediterranean populations of B. stacei . Significant association was found for pollen grain length and lemma length and ten and six metabolomic signals, respectively. These results would guide the selection of new germplasm lines of the three model grasses in ongoing genome-wide association studies.

Metabolic changes in response to varying whole-grain wheat and rye intake.

Epidemiological studies have shown associations between whole-grain intake and lowered disease risk. A sufficient level of whole-grain intake to reach the health benefits has not been established, and there is limited knowledge about the impact of whole-grain intake on metabolite levels. In this clinical intervention study, we aimed to identify plasma and urine metabolites associated with two different intake levels of whole-grain wheat and rye and to correlate them with clinical plasma biomarkers. Healthy volunteers (N = 68) were divided into two groups receiving either whole-grain wheat or whole-grain rye in two four-week interventions with 48 and 96 g/d of whole grains consumed. The metabolomics of the plasma samples was performed with UPLC-QTOF-MS. Plasma alkylresorcinols were quantified with GC-MS and plasma and urinary mammalian lignans with HPLC-ECD. The high-dose intervention impacted the metabolite profile, including microbial metabolites, more in the rye-enriched diet compared with wheat. Among the increased metabolites were alkylresorcinol glucuronides, sinapyl alcohol, and pipecolic acid betaine, while the decreased metabolites included acylcarnitines and ether lipids. Plasma alkylresorcinols, urinary enterolactone, and total mammalian lignans reflected the study diets in a dose-dependent manner. Several key metabolites linked with whole-grain consumption and gut microbial metabolism increased in a linear manner between the two interventions. The results reveal that an increase in whole-grain intake, particularly rye, is strongly reflected in the metabolite profile, is correlated with clinical variables, and suggests that a diet rich in whole grains promotes the growth and/or metabolism of microbes producing potentially beneficial microbial metabolites.

Deciphering systemic wound responses of the pumpkin extrafascicular phloem by metabolomics and stable isotope-coded protein labeling.

In cucurbits, phloem latex exudes from cut sieve tubes of the extrafascicular phloem (EFP), serving in defense against herbivores. We analyzed inducible defense mechanisms in the EFP of pumpkin (Cucurbita maxima) after leaf damage. As an early systemic response, wounding elicited transient accumulation of jasmonates and a decrease in exudation probably due to partial sieve tube occlusion by callose. The energy status of the EFP was enhanced as indicated by increased levels of ATP, phosphate, and intermediates of the citric acid cycle. Gas chromatography coupled to mass spectrometry also revealed that sucrose transport, gluconeogenesis/glycolysis, and amino acid metabolism were up-regulated after wounding. Combining ProteoMiner technology for the enrichment of low-abundance proteins with stable isotope-coded protein labeling, we identified 51 wound-regulated phloem proteins. Two Sucrose-Nonfermenting1-related protein kinases and a 32-kD 14-3-3 protein are candidate central regulators of stress metabolism in the EFP. Other proteins, such as the Silverleaf Whitefly-Induced Protein1, Mitogen Activated Protein Kinase6, and Heat Shock Protein81, have known defensive functions. Isotope-coded protein labeling and western-blot analyses indicated that Cyclophilin18 is a reliable marker for stress responses of the EFP. As a hint toward the induction of redox signaling, we have observed delayed oxidation-triggered polymerization of the major Phloem Protein1 (PP1) and PP2, which correlated with a decline in carbonylation of PP2. In sum, wounding triggered transient sieve tube occlusion, enhanced energy metabolism, and accumulation of defense-related proteins in the pumpkin EFP. The systemic wound response was mediated by jasmonate and redox signaling.

Acute oral administration of a tyrosine and phenylalanine-free amino acid mixture reduces exercise capacity in the heat.

Acute tyrosine administration is associated with increased exercise capacity in the heat. To explore whether reduced plasma tyrosine and phenylalanine (tyrosine precursor) is associated with impaired exercise capacity in the heat, eight healthy, moderately trained male volunteers, unacclimated to exercise in the heat, performed two tests in a crossover design separated by at least 7 days. In a randomised, double-blind fashion, subjects ingested 500 mL flavoured, sugar-free water containing amino acids [(TYR-free; isoleucine 15 g, leucine 22.5 g, valine 17.5 g, lysine 17.5 g, methionine 5 g, threonine 10 g, tryptophan 2.5 g)] to lower the ratio of plasma tyrosine plus phenylalanine:amino acids competing for blood-brain barrier uptake (CAA), a key determinant of brain uptake, or a balanced mixture (BAL; TYR-free plus 12.5 g tyrosine and 12.5 g phenylalanine). One hour later, subjects cycled to exhaustion at 63 ± 5 % [Formula: see text]O2peak in 30 °C and 60 % relative humidity. Pre-exercise ratio of plasma tyrosine plus phenylalanine:ΣCAA declined 75 ± 5 % from rest in TYR-free (P < 0.001), but was unchanged in BAL (P = 0.061). Exercise time was shorter in TYR-free (59.8 ± 19.0 min vs. 66.2 ± 16.9 min in TYR-free and BAL respectively; P = 0.036). Heart rate (P = 0.298), core (P = 0.134) and skin (P = 0.384) temperature, RPE (P > 0.05) and thermal sensation (P > 0.05) were similar at exhaustion in both trials. These data indicate that acutely depleting plasma catecholamine precursors:ΣCAA is associated with reduced submaximal exercise capacity in the heat.

Corrigendum: Identification and metabolomic characterization of potent anti-MRSA phloroglucinol derivatives from Dryopteris crassi rhizoma Nakai (Polypodiaceae).

[This corrects the article DOI: 10.3389/fphar.2022.961087.].

Small Molecule Ligands of the BET-like Bromodomain, SmBRD3, Affect Schistosoma mansoni Survival, Oviposition, and Development.

Schistosomiasis is a disease affecting >200 million people worldwide, but its treatment relies on a single agent, praziquantel. To investigate new avenues for schistosomiasis control, we have conducted the first systematic analysis of bromodomain-containing proteins (BCPs) in a causative species, Schistosoma mansoni. Having identified 29 putative bromodomains (BRDs) in 22 S. mansoni proteins, we selected SmBRD3, a tandem BRD-containing BCP that shows high similarity to the human bromodomain and extra terminal domain (BET) family, for further studies. Screening 697 small molecules identified the human BET BRD inhibitor I-BET726 as a ligand for SmBRD3. An X-ray crystal structure of I-BET726 bound to the second BRD of SmBRD3 [SmBRD3(2)] enabled rational design of a quinoline-based ligand (15) with an ITC Kd = 364 ± 26.3 nM for SmBRD3(2). The ethyl ester pro-drug of compound 15 (compound 22) shows substantial effects on sexually immature larval schistosomula, sexually mature adult worms, and snail-infective miracidia in ex vivo assays.

Identification and metabolomic characterization of potent anti-MRSA phloroglucinol derivatives from Dryopteris crassirhizoma Nakai (Polypodiaceae).

Traditional Chinese medicine (TCM) has been used to treat infectious diseases and could offer potential drug leads. This study evaluates the in vitro antimicrobial activities from commercially sourced Dryopteris crassirhizoma Nakai (Polypodiaceae) whose authenticity was confirmed by DNA barcoding based on the ribulose bisphosphate carboxylase (rbcL) gene. Powdered rhizomes were sequentially extracted using n-hexane, dichloromethane, ethyl acetate, and methanol at ambient temperature. The dried extracts at different concentrations were tested for antimicrobial activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Mycobacterium smegmatis. D. crassirhizoma extracts exhibited significant antimicrobial activities only against MRSA (minimum inhibitory concentration: 3.125 µg/ml n-hexane extract). Activity-led fractionations of D. crassirhizoma and characterization by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) targeted a fraction (A3), with two anti-MRSA phloroglucinol derivatives, flavaspidic acid AB and norflavaspidic acid AB-being greatly enriched in the latter. The impact of A3 on MRSA cells was examined using untargeted metabolomic analysis and compared to that of other established antibiotics (all treatments normalized to MIC50 at 6 h). This suggested that norflavaspidic acid AB had distinctive effects, one of which involved targeting bioenergetic transformation, metabolism, and particularly acetyl-CoA, on MRSA cells. No cytotoxicity was observed for the norflavaspidic acid AB-enriched fraction against murine HepG2 cells. This study requires further experimental validation but can have indicated a naturally available compound that could help counter the threat of clinically relevant strains with antibiotic resistance.