Metabolomic insights into the browning inhibition of fresh-cut apple by hydrogen sulfide

Hydrogen sulfide (H2S) is known to effectively inhibit the browning of fresh-cut apples, but the mechanism at a metabolic level remains unclear. Herein, non-targeted metabolomics was used to analyze metabolic changes in surface and internal tissues of fresh-cut apple after H2S treatment. The results showed that prenol lipids were the most up-accumulated differential metabolites in both surface and inner tissue of fresh-cut apple during browning process, which significantly down-accumulated by H2S treatment. H2S treatment reduced the consumption of amino acid in surface tissue. Regarding inner tissue, H2S activated defense response through accumulation of lysophospholipid signaling and induced the biosynthesis of phenolic compounds. We therefore propose that H2S inhibited the surface browning of fresh-cut apple by reducing the accumulation of prenol lipids, directly delaying amino acid consumption in surface tissue and indirectly regulating defense response in inner tissue, which provides fundamental insights into browning inhibition mechanisms by H2S.

A GC×GC-MS method based on solid-state modulator for non-targeted metabolomics: Comparison with traditional GC-MS method

The formidable challenge posed by the presence of extremely high amounts of compounds and large differences in concentrations in plasma significantly complicates non-targeted metabolomics analyses. In this study, a comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC×GC-qMS) method with a solid-state modulator (SSM) for non-targeted metabolomics in beagle plasma was first established based on a GC-MS method, and the qualitative and quantitative performance of the two platforms were compared. Identification of detected compounds was accomplished utilizing NIST database match scores, retention indices (RIs) and standards. Semi-quantification involved the calculation of peak area ratios to internal standards. Metabolite identification sheets were generated for plasma samples on both analytical platforms, featuring 22 representative metabolites chosen for validating qualitative accuracy, and for conducting comparisons of linearity, accuracy, precision, and sensitivity. The outcomes revealed a threefold increase in the number of identifiable metabolites on the GC×GC-MS platform, with lower limits of quantitation (LLOQs) reduced to 0.5-0.05 times those achieved on the GC-MS platform. Accuracy in quantification for both GC×GC-MS and GC-MS fell within the range of 85-115%, and the vast majority of intra- and inter-day precisions were within the range of 20%. These findings underscore that relative to the conventional GC-MS method, the GC×GC-MS method developed in this study, combined with SSM, exhibits enhanced qualitative capabilities, heightened sensitivity, and comparable accuracy and precision, rendering it more suitable for non-targeted metabolomics analyses.

Spatial metabolome of biosynthesis and metabolism in Cyclocarya paliurus leaves

A large number of plant metabolites were discovered, but their biosynthetic and metabolic pathways are still largely unknown. However, the spatial distribution of metabolites and their changes in metabolic pathways can be supplemented by mass spectrometry imaging (MSI) techniques. For this purpose, the combination of desorption electrospray ionization (DESI)-MSI and non-targeted metabolomics was used to obtain the spatial distribution information of metabolites in the leaves of Cyclocarya paliurus (Batal.) Iljinskaja (C. paliurus). The sample pretreatment method was optimized to have higher detection sensitivity in DESI. The changes of metabolites in C. paliurus were analyzed in depth with the integration of the spatial distribution information of metabolites. The main pathways for biosynthesis of flavonoid precursor and the effect of changes in compound structure on the spatial distribution were found. Spatial metabolomics can provide more metabolite information and a platform for the in-depth understanding of the biosynthesis and metabolism in plants.

Identification of metabolites produced by six gut commensal Bacteroidales strains using non-targeted LC-MS/MS metabolite profiling

As the most abundant gram-negative bacterial order in the gastrointestinal tract, Bacteroidales bacteria have been extensively studied for their contribution to various aspects of gut health. These bacteria are renowned for their involvement in immunomodulation and their remarkable capacity to break down complex carbohydrates and fibers. However, the human gut microbiota is known to produce many metabolites that ultimately mediate important microbe-host and microbe-microbe interactions. To gain further insights into the metabolites produced by the gut commensal strains of this order, we examined the metabolite composition of their bacterial cell cultures in the stationary phase. Based on their abundance in the gastrointestinal tract and their relevance in health and disease, we selected a total of six bacterial strains from the relevant genera Bacteroides, Phocaeicola, Parabacteroides, and Segatella. We grew these strains in modified Gifu anaerobic medium (mGAM) supplemented with mucin, which resembles the gut microbiota's natural environment. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based metabolite profiling revealed 179 annotated metabolites that had significantly differential abundances between the studied bacterial strains and the control growth medium. Most of them belonged to classes such as amino acids and derivatives, organic acids, and nucleot(s)ides. Of particular interest, Segatella copri DSM 18205 (previously referred to as Prevotella copri) produced substantial quantities of the bioactive metabolites phenylethylamine, tyramine, tryptamine, and ornithine. Parabacteroides merdae CL03T12C32 stood out due to its ability to produce cadaverine, histamine, acetylputrescine, and deoxycarnitine. In addition, we found that strains of the genera Bacteroides, Phocaeicola, and Parabacteroides accumulated considerable amounts of proline-hydroxyproline, a collagen-derived bioactive dipeptide. Collectively, these findings offer a more detailed comprehension of the metabolic potential of these Bacteroidales strains, contributing to a better understanding of their role within the human gut microbiome in health and disease.

Rewiring cis-2-butene-1,4-dial mediated urinary metabolomics fingerprints of short-term exposure to furan

Furan represents one of the dietary-sourced persistent organic pollutants and thermal processing contaminants. Given its widespread occurrence in food and various toxicological effects, accurately assessing furan exposure is essential for informing public health risks. Furan is metabolized to a reactive primary product, cis-2-butene-1,4-dial (BDA) upon absorption. Some of the resulting BDA-derived metabolites have been proposed as potential exposure biomarkers of furan. However, the lack of quantification for recognized and feasible furan biomarkers has hampered the development of internal exposure risk assessment of furan. In this study, we employed reliable non-targeted metabolomics techniques to uncover urinary furan metabolites and elucidate their chemical structures. We characterized 8 reported and 11 new furan metabolites derived from the binding of BDA with glutathione (GSH), biogenic amines, and/or amino acids in the urine of male rats subjected to varying doses of furan. Notably, a mono-GSH-BDA adduct named cyclic GSH-BDA emerged as a highly prospective specific biomarker of furan exposure, as determined by an ultrahigh-performance liquid chromatography-tandem mass spectrometry method. Cyclic GSH-BDA demonstrated a robust mass spectrometry ion response intensity and exhibited evident time- and dose response. Additionally, we conducted a comprehensive profiling of the kinetics of potential furan biomarkers over time to capture the metabolic dynamics of furan in vivo. Most urinary furan metabolites reached peak concentrations at either the first (3 h) or second (6 h) sampling time point and were largely eliminated within 36 h following furan treatment. The present study provides novel insights into furan metabolism and sheds light on the biomonitoring of furan exposure.

Integration of non-targeted/targeted metabolomics and electronic sensor technology reveals the chemical and sensor variation in 12 representative yellow teas

Yellow tea is a lightly fermented tea with unique sensory qualities and health benefits. However, chemical composition and sensory quality of yellow tea products have rarely been studied. 12 representative yellow teas, which were basically covered the main products of yellow tea, were chosen in this study. Combined analysis of non-targeted/targeted metabolomics and electronic sensor technologies (E-eye, E-nose, E-tongue) revealed the chemical and sensor variation. The results showed that yellow big tea differed greatly from yellow bud teas and yellow little teas, but yellow bud teas could not be effectively distinguished from yellow little teas based on chemical constituents and electronic sensory characteristics. Sensor variation of yellow teas might be attributed to some compounds related to bitterness and aftertaste-bitterness (4'-dehydroxylated gallocatechin-3-O-gallate, dehydrotheasinensin C, myricitin 3-O-galactoside, phloroglucinol), aftertaste-astringency (methyl gallate, 1,5-digalloylglucose, 2,6-digalloylglucose), and sweetness (maltotriose). This study provided a comprehensive understanding of yellow tea on chemical composition and sensory quality.

Mechanic evaluation of Wu-Mei-Pill on colitis-associated colorectal cancer: An integrated transcriptomics, metabolomics, and experimental validation study

BACKGROUND

Chronic intestinal inflammatory diseases play a crucial role in the onset of colorectal cancer (CRC). Effectively impeding the progression of colitis-associated colorectal cancer (CAC) can be instrumental in hindering CRC development. Wu-Mei-Pill (WMP), a formulation comprising various herbal extracts, is clinically employed for CAC treatment, yet the underlying mechanism of WMP's efficacy in CAC remains unclear. Our study firstly demonstrated the effects and mechanisms of WMP on transcriptional and metabolic levels based on integrated transcriptomics and untargeted metabolomics and relative experimental validations.

MATERIALS AND METHODS

A CAC mouse model was established through a single injection of azoxymethane (AOM) followed by intermittent dextran sodium sulfate (DSS) intervention, with subsequent WMP administration. Initially, the therapeutic impact of WMP on the CAC model was assessed by observing survival rate, body weight change, colon length, tumor number, tumor load, and pathological changes in the colon tissue of CAC mice post-WMP intervention. Subsequently, differential genes and metabolites in the colorectal tissue of CAC mice following WMP intervention were identified through transcriptomics and non-targeted metabolomics. Finally, the influence of WMP on the peroxisome proliferator activated receptor (PPAR) pathway, Wnt pathway, and CC motif chemokine ligand 3 (CCL3)/ CC motif chemokine receptor 1 (CCR1) axis in CAC mice was verified through western blot, immunofluorescence, and ELISA based on the results of transcriptomics and non-targeted metabolomics.

RESULTS

WMP intervention enhanced survival, alleviated body weight loss, shortened colon length, tumor occurrence, and pathological changes in the colorectal tissue of CAC mice, such as glandular damage, tumourigenesis, and inflammatory cell infiltration. Transcriptomic and non-targeted metabolomic results revealed that WMP intervention up-regulated the expression of key regulatory mechanisms of fatty acid oxidation PPAR pathway-related genes (Pparg, Ppara, Cpt1a, and Acadm) and metabolites (L-carnitine and L-palmitoylcarnitine). Additionally, it down-regulated Wnt pathway-related genes (Wnt3, Axin2, Tcf7, Mmp7, Lgr5, Wnt5a, Fzd6, Wnt7b, Lef1, and Fzd10 etc.) and pro-inflammatory related genes (Il1b, Il6, Il17a, Ccl3, and Ccr1 etc.). Experimental validation demonstrated that WMP up-regulated PPAR pathway-related proteins [PPARγ, PPARα, carnitine palmitoyltransferase 1A (CPT1A), and acyl-CoA dehydrogenase medium chain (ACADM)] in the colorectal tissue of CAC mice. It also down-regulated Wnt pathway-related proteins [β-catenin, T-cell factor (TCF), lymphoid enhancer-binding factor (LEF), and matrix metallopeptidase 7 (MMP7)], inhibited the nuclear translocation of the key transcription factor β-catenin in the Wnt pathway, and suppressed epithelial-to-mesenchymal transition (EMT) activation induced by the Wnt pathway (up-regulated E-cadherin and down-regulated Vimentin). Furthermore, WMP intervention reduced pro-inflammatory factors [interleukin (IL)-6, IL-1β, and IL-17A] and decreased CCL3/CCR1 axis factors, including CCL3 protein levels and diminished F4/80+CCR1+ positive expressed cells.

CONCLUSION

WMP significantly inhibits CAC tumorigenesis by up-regulating PPARα-mediated fatty acid oxidation, inhibiting the Wnt signaling pathway-mediated EMT, and suppressing CCL3/CCR1-mediated inflammatory responses.

Inhibition of anaerobic digestion by various ammonia sources resulted in subtle differences in metabolite dynamics

The impact of ammonia on anaerobic digestion performance and microbial dynamics has been extensively studied, but the concurrent effect of anions brought by ammonium salt should not be neglected. This paper studied this effect using metabolomics and a time-course statistical framework. Metabolomics provides novel perspectives to study microbial processes and facilitates a more profound understanding at the metabolic level. The advanced statistical framework enables deciphering the complexity of large metabolomics data sets. More specifically, a series of lab-scale batch reactors were set up with different ammonia sources added. Samples of nine time points over the degradation were analyzed with liquid chromatography-mass spectrometry. A filtering procedure was applied to select the promising metabolomic peaks from 1262 peaks, followed by modeling their intensities across time. The metabolomic peaks with similar time profiles were clustered, evidencing the correlation of different biological processes. Differential analysis was performed to seek the differences in metabolite dynamics caused by different anions. Finally, tandem mass spectrometry and metabolite annotation provided further information on the molecular structure and possible metabolic pathways. For example, the consumption of 5-aminovaleric acid, a short-chain fatty acid obtained from l-lysine degradation, was slowed down by phosphates. Overall, by investigating the effect of anions on anaerobic digestion, our study demonstrated the effectiveness of metabolomics in providing detailed information in a set of samples from different experimental conditions. With the statistical framework, the approach enables capturing subtle differences in metabolite dynamics between samples while accounting for the differences caused by time variations.

Rootstock vigor dictates the canopy light environment that regulates metabolite profile and internal fruit quality development in peach

Five rootstock cultivars of differing vigor: vigorous ('Atlas™' and 'Bright's Hybrid® 5'), standard ('Krymsk® 86' and 'Lovell') and dwarfing ('Krymsk® 1') grafted with 'Redhaven' as the scion were studied for their impact on productivity, mid-canopy photosynthetic active radiation transmission (i.e., light availability) and internal fruit quality. Αverage yield (kg per tree) and fruit count increased significantly with increasing vigor (trunk cross sectional area, TCSA). Α detailed peach fruit quality analysis on fruit of equal maturity (based on the index of absorbance difference, IAD) coming from trees with equal crop load (no. of fruit cm-2 of TCSA) characterized the direct impact of rootstock vigor on peach internal quality [dry matter content (DMC) and soluble solids concentration (SSC)]. DMC and SSC increased significantly with decreasing vigor and increasing light availability, potentially due to reduced intra-tree shading and better light distribution within the canopy. Physiologically characterized peach fruit mesocarp was further analyzed by non-targeted metabolite profiling using gas chromatography mass spectrometry (GC-MS). Metabolite distribution was associated with rootstock vigor class, mid-canopy light availability and fruit quality characteristics. Fructose, glucose, sorbose, neochlorogenic and quinic acids, catechin and sorbitol were associated with high light environments and enhanced quality traits, while sucrose, butanoic and malic acids related to low light conditions and inferior fruit quality. These outcomes show that while rootstock genotype and vigor are influencing peach tree productivity and yield, their effect on manipulating the light environment within the canopy also plays a significant role in fruit quality development.

Refined metabolite profiling in the collateral circulation of chronic total occlusion of coronary arteries: Insights from a metabolomics investigation

Background and aims

To investigate the disparities in coronary collateral circulation (CCC) and peripheral serum metabolites among patients presenting with chronic total occlusion (CTO) of the coronary arteries, a non-targeted metabolic approach was employed.

Methods

A cohort of 22 patients diagnosed with CTO of coronary arteries in the context of coronary heart disease (CHD) was selected for blood sample collection from CCC and peripheral arteries. The patients were categorized into two groups, namely CTO-C and CTO-P. The Waters UPLC I-Class Plus is combined with the Q Exactive high-resolution mass spectrometer for metabolite separation and detection. The acquired raw data from mass spectrometry is subsequently imported into Compound Discoverer 3.2 software for comprehensive analysis, which seamlessly integrates the BGI Metabolome Database (BMDB), mzCloud database, and ChemSpider online database. Subsequently, the identified differential metabolites were subjected to a metabolic pathway enrichment analysis, as documented in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database.

Results

A total of 403 differential metabolites were identified in CCC and peripheral serum samples from patients with CTO of coronary arteries in CHD. Compared to the CTO-P group, the CTO-C group exhibited decreased levels of metabolites such as Testosterone, dehydroepiandrosterone (DHA), deoxyacetone, while demonstrating increased levels of metabolites including Progesterone, androstanone, l-threonine. The biosynthesis pathway of steroid hormones emerges as the key metabolic pathway significantly associated with differential metabolites.

Conclusions

Through metabolomics analysis, distinct differences in the CCC and peripheral serum metabolites have been identified among patients with CTO of coronary artery. Notably, a significant association between the steroid hormone biosynthesis pathway and CCC has been observed.

Analysis of dog meat adulteration in beef meatballs using non-targeted UHPLC-Orbitrap HRMS metabolomics and chemometrics for halal authentication study

Due to the different price and high quality, halal meat such as beef can be adulterated with non-halal meat with low price to get an economical price. The objective of this research was to develop an analytical method for halal authentication testing of beef meatballs (BM) from dog meat (DM) using a non-targeted metabolomics approach employing liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and chemometrics. The differentiation of authentic BM from that adulterated with DM was successfully performed using partial least square-discriminant analysis (PLS-DA) with high accuracy (R2X = 0.980, and R2Y = 0.980) and good predictivity (Q2 = 0.517). In addition, partial least square (PLS) and orthogonal PLS (OPLS) were successfully used to predict the DM added (% w/w) in BM with high accuracy (R2 > 0.990). A number of metabolites, potential for biomarker candidates, were identified to differentiate BM and that adulterated with DM. It showed that the combination of a non-targeted LC-HRMS Orbitrap metabolomics and chemometrics could detect up to 0.1% w/w of DM adulteration. The developed method was successfully applied for analysis of commercial meatball samples (n = 28). Moreover, pathway analysis revealed that beta-alanine, histidine, and ether lipid metabolism were significantly affected by dog meat adulteration. In summary, this developed method has great potential to be developed and used as an alternative method for analysis of non-halal meats in halal meat products.

Biosurfactants-based mixed polycyclic aromatic hydrocarbon degradation: From microbial community structure toward non-targeted metabolomic profile determination

Biosurfactants-based bioremediation is considered an efficient technology to eliminate environmental pollutants including polycyclic aromatic hydrocarbons (PAHs). However, the precise role of rhamnolipids or lipopeptide-biosurfactants in mixed PAH dissipation, shaping microbial community structure, and influencing metabolomic profile remained unclear. In this study, results showed that the maximum PAH degradation was achieved in lipopeptide-assisted treatment (SPS), where the pyrene and phenanthrene were substantially degraded up to 74.28 % and 63.05 % respectively, as compared to rhamnolipids (SPR) and un-aided biosurfactants (SP). Furthermore, the high throughput sequencing analysis revealed a significant change in the PAH-degrading microbial community, with Proteobacteria being the predominant phylum (>98 %) followed by Bacteroidota and Firmicutes in all the treatments. Moreover, Pseudomonas and Pannonibacter were found as highly potent bacterial genera for mixed PAH degradation in SPR, SPS, and SP treatments, nevertheless, the abundance of the genus Pseudomonas was significantly enhanced (>97 %) in SPR treatment groups. On the other hand, the non-targeted metabolomic profile through UHPLC-MS/MS exhibited a remarkable change in the metabolites of amino acids, carbohydrates, and lipid metabolisms by the input of rhamnolipids or lipopeptide-biosurfactants whereas, the maximum intensities of metabolites (more than two-fold) were observed in SPR treatment. The findings of this study suggested that the aforementioned biosurfactants can play an indispensable role in mixed PAH degradation as well as seek to offer new insights into shifts in PAH-degrading microbial communities and their metabolic function, which can guide the development of more efficient and targeted strategies for complete removal of organic pollutants such as PAH from the contaminated environment.

Changes in flavor and biological activities of Lentinula edodes hydrolysates after Maillard reaction

This study aimed to elucidate how the Maillard reaction (MR) affects the flavor and bioactivities of Lentinula edodes hydrolysates (LEHs). Changes in flavor were investigated using non-targeted metabolomics techniques (GC-MS and LC-MS/MS) and sensory evaluation. Simultaneously, UV absorption, fluorescence, and FT-IR spectra were used to characterize the process of MR. We also evaluated the effects of MR on the antioxidant activity, hypoglycemic activity and antimicrobial activity of LEHs in vitro. The results revealed that MR produced many volatile aldehydes and ketones and decreased the content of most amino acids, sugars and flavonoids in the LEHs while increasing the content of l-theanine and succinic acid. MRPs had a strong caramel and like-meat flavor and an obvious improvement in umami, taste continuity, and total acceptability. Furthermore, MR improved the antioxidant and antimicrobial properties of LEHs. This research establishes a theoretical foundation for MR in the deep processing of edible mushrooms.

Maize (Zea mays L.) root exudation profiles change in quality and quantity during plant development - A field study

Deciphering root exudate composition of soil-grown plants is considered a crucial step to better understand plant-soil-microbe interactions affecting plant growth performance. In this study, two genotypes of Zea mays L. (WT, rth3) differing in root hair elongation were grown in the field in two substrates (sand, loam) in custom-made, perforated columns inserted into the field plots. Root exudates were collected at different plant developmental stages (BBCH 14, 19, 59, 83) using a soil-hydroponic-hybrid exudation sampling approach. Exudates were characterized by LC-MS based non-targeted metabolomics, as well as by photometric assays targeting total dissolved organic carbon, soluble carbohydrates, proteins, amino acids, and phenolics. Results showed that plant developmental stage was the main driver shaping both the composition and quantity of exuded compounds. Carbon (C) exudation per plant increased with increasing biomass production over time, while C exudation rate per cm² root surface area h-1 decreased with plant maturity. Furthermore, exudation rates were higher in the substrate with lower nutrient mobility (i.e., loam). Surprisingly, we observed higher exudation rates in the root hairless rth3 mutant compared to the root hair-forming WT sibling, though exudate metabolite composition remained similar. Our results highlight the impact of plant developmental stage on the plant-soil-microbe interplay.

Enhancement of the organic acid content and antioxidant capacity of yellow whey through fermentation with Lacticaseibacillus casei YQ336

Fermentation is considered an effective tool for improving the functional characteristics of food. In this study, Lacticaseibacillus casei YQ336 was used to ferment yellow whey, and physical and chemical analysis was performed to identify the changes in the nutritional components and antioxidant activity of the fermented yellow whey. Non-targeted metabolomics was used to study the transformation of small molecular substances in the fermented yellow whey. After 48 h of pure culture fermentation with L. casei YQ336, the pH of yellow whey decreased significantly (p < 0.05). Meanwhile, the content of total acids, organic acids, sugars, total phenols, and total flavonoids and the antioxidant activity showed a significant increase (p < 0.05). A total of 628 differential metabolites were identified between fermented and unfermented yellow whey samples, of which 293 were upregulated and 335 were downregulated. After fermentation, due to the growth and metabolic activity of L. casei YQ336, meaningful metabolites such as homovanillic acid, lactic acid, oxalic acid, L-glutamic acid, and phenylalanine, as well as phenyllactic acid, gallic acid, and genistein were produced. This increased the organic acid content and antioxidant activity of yellow whey. The findings provide a theoretical and practical basis for further research on the bio-functional activity of yellow whey and the recycling and utilization of food by-products.

Changes in liver metabolic pathways demonstrate efficacy of the combined dietary and microbial therapeutic intervention in MASLD mouse model

OBJECTIVE

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is the most prevalent liver disease globally, yet no therapies are approved. The effects of Escherichia coli Nissle 1917 expressing aldafermin, an engineered analog of the intestinal hormone FGF19, in combination with dietary change were investigated as a potential treatment for MASLD.

METHODS

MASLD was induced in C57BL/6J male mice by American lifestyle-induced obesity syndrome diet and then switched to a standard chow diet for seven weeks. In addition to the dietary change, the intervention group received genetically engineered E. coli Nissle expressing aldafermin, while control groups received either E. coli Nissle vehicle or no treatment. MASLD-related plasma biomarkers were measured using an automated clinical chemistry analyzer. The liver steatosis was assessed by histology and bioimaging analysis using Fiji (ImageJ) software. The effects of the intervention in the liver were also evaluated by RNA sequencing and liquid-chromatography-based non-targeted metabolomics analysis. Pathway enrichment studies were conducted by integrating the differentially expressed genes from the transcriptomics findings with the metabolites from the metabolomics results using Ingenuity pathway analysis.

RESULTS

After the intervention, E. coli Nissle expressing aldafermin along with dietary changes reduced body weight, liver steatosis, plasma aspartate aminotransferase, and plasma cholesterol levels compared to the two control groups. The integration of transcriptomics with non-targeted metabolomics analysis revealed the downregulation of amino acid metabolism and related receptor signaling pathways potentially implicated in the reduction of hepatic steatosis and insulin resistance. Moreover, the downregulation of pathways linked to lipid metabolism and changes in amino acid-related pathways suggested an overall reduction of oxidative stress in the liver.

CONCLUSIONS

These data support the potential for using engineered microbial therapeutics in combination with dietary changes for managing MASLD.

Integrated microbiome and metabolome analysis reveals a distinct microbial and metabolic signature in Graves' disease and hypothyroidism

Recent studies reveal that imbalanced microbiota is related to thyroid diseases. However, studies on the alterations in fecal metabolites in Graves' disease and clinical hypothyroidism patients are insufficient. Here, we identified 21 genera and 53 metabolites that were statistically significant among Graves' disease patients, hypothyroidism patients, and controls integrating microbiome and untargeted metabolome analysis. Disease groups revealed a decreased abundance in butyrate-producing microbiota and an increased abundance in potentially pathogenic microbiota. Lipids molecules were the major differential metabolites identified in all fecal samples. Network analysis recognized that microbiota may affect thyroid function by targeting specific metabolites. We further identified specific microbiota and metabolites that could distinguish Graves' disease patients, hypothyroidism patients, and controls. Our study reveals a distinct microbial and metabolic signature in hypothyroidism patients and Graves' disease patients and further validates the potential role of microbiota in thyroid diseases, providing new ideas for future research into the etiology and clinical intervention of thyroid diseases.

Peanut skin procyanidins reduce intestinal glucose transport protein expression, regulate serum metabolites and ameliorate hyperglycemia in diabetic mice

One of diabetic characteristics is the postprandial hyperglycemia. Inhibiting glucose uptake may be beneficial for controlling postprandial blood glucose levels and regulating the glucose metabolism Peanut skin procyanidins (PSP) have shown a potential for lowering blood glucose; however, the underlying mechanism through which PSP regulate glucose metabolism remains unknown. In the current study, we investigated the effect of PSP on intestinal glucose transporters and serum metabolites using a mouse model of diabetic mice. Results showed that PSP improved glucose tolerance and systemic insulin sensitivity, which coincided with decreased expression of sodium-glucose cotransporter 1 and glucose transporter 2 in the intestinal epithelium induced by an activation of the phospholipase C β2/protein kinase C signaling pathway. Moreover, untargeted metabolomic analysis of serum samples revealed that PSP altered arachidonic acid, sphingolipid, glycerophospholipid, bile acids, and arginine metabolic pathways. The study provides new insight into the anti-diabetic mechanism of PSP and a basis for further research.

Impacts of maternal microbiota and microbial metabolites on fetal intestine, brain, and placenta

BACKGROUND

The maternal microbiota modulates fetal development, but the mechanisms of these earliest host-microbe interactions are unclear. To investigate the developmental impacts of maternal microbial metabolites, we compared full-term fetuses from germ-free and specific pathogen-free mouse dams by gene expression profiling and non-targeted metabolomics.

RESULTS

In the fetal intestine, critical genes mediating host-microbe interactions, innate immunity, and epithelial barrier were differentially expressed. Interferon and inflammatory signaling genes were downregulated in the intestines and brains of the fetuses from germ-free dams. The expression of genes related to neural system development and function, translation and RNA metabolism, and regulation of energy metabolism were significantly affected. The gene coding for the insulin-degrading enzyme (Ide) was most significantly downregulated in all tissues. In the placenta, genes coding for prolactin and other essential regulators of pregnancy were downregulated in germ-free dams. These impacts on gene expression were strongly associated with microbially modulated metabolite concentrations in the fetal tissues. Aryl sulfates and other aryl hydrocarbon receptor ligands, the trimethylated compounds TMAO and 5-AVAB, Glu-Trp and other dipeptides, fatty acid derivatives, and the tRNA nucleobase queuine were among the compounds strongly associated with gene expression differences. A sex difference was observed in the fetal responses to maternal microbial status: more genes were differentially regulated in male fetuses than in females.

CONCLUSIONS

The maternal microbiota has a major impact on the developing fetus, with male fetuses potentially more susceptible to microbial modulation. The expression of genes important for the immune system, neurophysiology, translation, and energy metabolism are strongly affected by the maternal microbial status already before birth. These impacts are associated with microbially modulated metabolites. We identified several microbial metabolites which have not been previously observed in this context. Many of the potentially important metabolites remain to be identified.

Study on taste quality formation and leaf conducting tissue changes in six types of tea during their manufacturing processes

This study fristly investigated the taste quality formation and leaf conducting tissue changes in six types of Chinese tea (green, black, oolong, yellow, white, and dark) made from Mingke No.1 variety. Non-targeted metabolomics showed the vital manufacturing processes (green tea-de-enzyming, black tea-fermenting, oolong tea-turning-over, yellow tea-yellowing, white tea-withering, and dark tea-pile-fermenting) were highly related to their unique taste formation, due to different fermentation degree in these processes. After drying, the retained phenolics, theanine, caffeine, and other substances significantly impacted each tea taste quality formation. Meanwhile, the tea leaf conducting tissue structure was significantly influenced by high processing temperature, and the change of its inner diameter was related to moisture loss during tea processing, as indicated by its significant different Raman characteristic peaks (mainly cellulose and lignin) in each key process. This study provides a reference for process optimization to improve tea quality.

Improving flavor, bioactivity, and changing metabolic profiles of goji juice by selected lactic acid bacteria fermentation

Lactic acid bacteria (LAB) have exhibited strain/species specificity for different food matrices. We investigated the impact of LAB fermentation on the flavor, chemical profile, and bioactivity of goji juice. The colony counts of five selected strains reached above 8.5 log CFU/mL. The fermentation increased the organic acids, decreased the sugars, and improved the sensory quality of goji juice. The majority of the strains had increased acetic acid, heptanoic acid, ethyl phenylacetate, and linalool levels. Specific strains suppressed α-glucosidase and pancreatic lipase activities and increased the antioxidant activities of fermented goji juice. Based on non-targeted metabolomics and activities, 23 important differential metabolites were screened among 453 metabolites. The quantification results showed that isoquercitrin and m-coumaric content varied among strains, reflecting the strain specificity in flavone and flavonol biosynthesis and phenylalanine, tyrosine, and tryptophan biosynthesis. These findings will provide useful information for fermented goji juice biochemistry research.

Sustained oral intake of nano-iron oxide perturbs the gut-liver axis

Nanomaterial have shown excellent properties in the food industry. Although iron oxides are often considered safe and widely used as food additives, the toxicity of nano‑iron oxide remains unclear. Here we established a subchronic exposure mouse model by gavage, tested the biodistribution of nano‑iron oxide, and explored the mechanism of liver injury caused by it through disturbance of the gut-liver axis. Oral intake of nano‑iron oxide will likely disrupt the small intestinal epithelial barrier, induce hepatic lipid metabolism disorders through the gut-liver axis, and cause hepatic damage accompanied with hepatic iron deposition. Nano‑iron oxide mainly caused hepatic lipid metabolism disorder by perturbing glycerophospholipid metabolism and the sphingolipid metabolism pathways, with the total abundance of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) tending to decrease while that of triglyceride tended to increase, in a time- and dose-dependent manner. The imbalanced lipid homeostasis could cause damage via membrane disruption, lipid accumulation, and lipotoxicity. This data provides information about the subchronic toxicity of nano‑iron oxide, highlights the importance of gut-liver axis in the hepatotoxicity.

Exploring preconception signatures of metabolites in mothers with gestational diabetes mellitus using a non-targeted approach

BACKGROUND

Metabolomic changes during pregnancy have been suggested to underlie the etiology of gestational diabetes mellitus (GDM). However, research on metabolites during preconception is lacking. Therefore, this study aimed to investigate distinctive metabolites during the preconception phase between GDM and non-GDM controls in a nested case-control study in Singapore.

METHODS

Within a Singapore preconception cohort, we included 33 Chinese pregnant women diagnosed with GDM according to the IADPSG criteria between 24 and 28 weeks of gestation. We then matched them with 33 non-GDM Chinese women by age and pre-pregnancy body mass index (ppBMI) within the same cohort. We performed a non-targeted metabolomics approach using fasting serum samples collected within 12 months prior to conception. We used generalized linear mixed model to identify metabolites associated with GDM at preconception after adjusting for maternal age and ppBMI. After annotation and multiple testing, we explored the additional predictive value of novel signatures of preconception metabolites in terms of GDM diagnosis.

RESULTS

A total of 57 metabolites were significantly associated with GDM, and eight phosphatidylethanolamines were annotated using HMDB. After multiple testing corrections and sensitivity analysis, phosphatidylethanolamines 36:4 (mean difference β: 0.07; 95% CI: 0.02, 0.11) and 38:6 (β: 0.06; 0.004, 0.11) remained significantly higher in GDM subjects, compared with non-GDM controls. With all preconception signals of phosphatidylethanolamines in addition to traditional risk factors (e.g., maternal age and ppBMI), the predictive value measured by area under the curve (AUC) increased from 0.620 to 0.843.

CONCLUSIONS

Our data identified distinctive signatures of GDM-associated preconception phosphatidylethanolamines, which is of potential value to understand the etiology of GDM as early as in the preconception phase. Future studies with larger sample sizes among alternative populations are warranted to validate the associations of these signatures of metabolites and their predictive value in GDM.

Carbon sufficiency boosts phenylpropanoid biosynthesis early in peach fruit development priming superior fruit quality

Manipulating the crop load in peach trees determines carbon supply and optimum balance between fruit yield and quality potentials. The impact of carbon supply on peach fruit quality was assessed in three development stages (S2, S3, S4) on fruit of equal maturity from trees that were carbon (C) starved (unthinned) and sufficient (thinned). Previous studies determined that primary metabolites of peach fruit mesocarp are mainly linked with developmental processes, thus, the secondary metabolite profile was assessed using non-targeted liquid chromatography mass-spectrometry (LC-MS). Carbon sufficient (C-sufficient) fruit demonstrated superior quality attributes as compared to C-starved fruit. Early metabolic shifts in the secondary metabolome appear to prime quality at harvest. Enhanced C-availability facilitated the increased and consistent synthesis of flavonoids, like catechin, epicatechin and eriodyctiol, via the phenylpropanoid pathway, providing a link between the metabolome and fruit quality, and serving as signatures of C-sufficiency during peach fruit development.

Ex vivo metabolomics-A hypothesis-free approach to identify native substrate(s) and product(s) of orphan enzymes

Over the past decade, the number of fully sequenced genomes has increased at an awe-inspiring pace. Similarly, the quality and scope of tools for the prediction of both protein structure and function has seen vast improvements. However, to pinpoint the exact function of a protein, for instance the exact reaction catalyzed by an enzyme, experimental evidence is crucial. At the same time, this step is the main bottleneck when generating a conclusive model for the function of an enzyme and to interpret its function in a physiological context. Hence, a comprehensive experimental strategy for functional annotation of enzymes that is as efficient as possible is required. Ex vivo metabolomics is a powerful non-targeted approach that overcomes several of the challenges inherent to in vitro characterization of enzymes with unknown functions. By incubating the recombinant enzyme of interest in a quasi-native metabolite extract from its tissue of origin under specific environmental and developmental conditions, the complete native substrate range can be tested in a single assay. This unlocks compounds that are commercially unavailable or otherwise difficult to procure. Coupled with non-targeted metabolomics analysis, ex vivo has the capability to test for and identify even unexpected substrates and assign the respective products of the enzymatic reaction.

Plasma Non-targeted Metabolomics Analysis of Yili Horses Raced on Tracks With Different Surface Hardness

In this study, the plasma non-targeted metabolomics of Yili horses were characterized before and after exercise on tracks that differed in surface hardness to better understand exercise-related biochemical changes. Blood samples were obtained from eight trained Yili horses before and immediately after exercise. Samples were used for metabolomic analysis by ultra-performance liquid chromatography-Q-EXACTIVE mass spectrometry. In total, 938 significantly different metabolites involving sugar, lipid, and amino acid metabolism were detected in the plasma, with significant increases in glucose, glucoheptanoic acid, lactic acid, malic acid, and methylmalonic acid and significant decreases in creatinine, D-tryptophan, carnitine, and citric acid after exercise. Among these metabolites, acetylcarnitine, tuliposide, vitamin C, and methylmalonic acid showed regular changes in concentration after exercise on tracks that differed in surface hardness, providing new insights into equine exercise physiology. The findings indicated the potential of vitamin C and methylmalonic acid as novel biomarkers of equine locomotor injury.

Metabolite fingerprinting: A powerful metabolomics approach for marker identification and functional gene annotation

Non-targeted metabolome approaches aim to detect metabolite markers related to stress, disease, developmental or genetic perturbation. In the later context, it is also a powerful means for functional gene annotation. A prerequisite for non-targeted metabolome analyses are methods for comprehensive metabolite extraction. We present three extraction protocols for a highly efficient extraction of metabolites from plant material with a very broad metabolite coverage. The presented metabolite fingerprinting workflow is based on liquid chromatography high resolution accurate mass spectrometry (LC-HRAM-MS), which provides suitable separation of the complex sample matrix for the analysis of compounds of different polarity by positive and negative electrospray ionization and mass spectrometry. The resulting data sets are then analyzed with the software suite MarVis and the web-based interface MetaboAnalyst. MarVis offers a straightforward workflow for statistical analysis, data merging as well as visualization of multivariate data, while MetaboAnalyst is used in our hands as complementary software for statistics, correlation networks and figure generation. Finally, MarVis provides access to species-specific metabolite and pathway data bases like KEGG and BioCyc and to custom data bases tailored by the user to connect the identified markers or features with metabolites. In addition, identified marker candidates can be interactively visualized and inspected in metabolic pathway maps by KEGG pathways for a more detailed functional annotation and confirmed by mass spectrometry fragmentation experiments or coelution with authentic standards. Together this workflow is a valuable toolbox to identify novel metabolites, metabolic steps or regulatory principles and pathways.

Direct introduction MALDI FTICR MS based on dried droplet deposition applied to non-targeted metabolomics on Pisum Sativum root exudates

Non-targeted metabolomic approaches based on direct introduction (DI) through a soft ionization source are nowadays used for large-scale analysis and wide cover-up of metabolites in complex matrices. When coupled with ultra-high-resolution Fourier-Transform ion cyclotron resonance (FTICR MS), DI is generally performed through electrospray (ESI), which, despite the great analytical throughput, can suffer of matrix effects due to residual salts or charge competitors. In alternative, matrix assisted laser desorption ionization (MALDI) coupled with FTICR MS offers relatively high salt tolerance but it is mainly used for imaging of small molecule within biological tissues. In this study, we report a systematic evaluation on the performance of direct introduction ESI and MALDI coupled with FTICR MS applied to the analysis of root exudates (RE), a complex mixture of metabolites released from plant root tips and containing a relatively high salt concentration. Classic dried droplet deposition followed by screening of best matrices and ratio allowed the selection of high ranked conditions for non-targeted metabolomics on RE. Optimization of MALDI parameters led to improved reproducibility and precision. A RE desalted sample was used for comparison on ionization efficiency of the two sources and ion enhancement at high salinity was highlighted in MALDI by spiking desalted solution with inorganic salts. Application of a true lyophilized RE sample exhibited the complementarity of the two sources and the ability of MALDI in the detection of undisclosed metabolites suffering of matrix effects in ESI mode.

The sulfoximine insecticide sulfoxaflor exposure reduces the survival status and disrupts the intestinal metabolism of the honeybee Apis mellifera

Honeybees (Apis mellifera) are indispensable pollinators in agricultural production, biodiversity conservation, and nutrients provision. The abundance and diversity of honeybees have been rapidly diminishing, possibly related to the extensive use of insecticides in ecosystems. Sulfoxaflor is a novel sulfoximine insecticide that, like neonicotinoids, acts as a competitive modulator of nicotinic acetylcholine receptors (nAChR) in insects. However, few studies have addressed the negative effects of sulfoxaflor on honeybees at environmentally relevant concentrations. In the present study, adult workers were fed a 50% (w/v) of sugar solution containing different concentrations (0, 0.05, 0.5 and 2.0 mg/L) of sulfoxaflor for two weeks consecutively. The survival rates, food intake, and body weight of the honeybees significantly decreased after continuous exposure at higher doses (0.5 and 2.0 mg/L) of sulfoxaflor when compared with the control. The change in the metabolites in the honeybee gut was determined using high-throughput non-targeted metabolomics on day 14 after sulfoxaflor treatment. The results revealed that 24 and 105 metabolites changed after exposure to 0.5 and 2.0 mg/L sulfoxaflor, respectively, compared with that of the control groups. A total of 12 changed compounds including pregenolone and glutathione were detected as potential biomarkers, which were eventually found to be enriched in pathways of the steroid hormone biosynthesis (p = 0.0001) and glutathione metabolism (p = 0.021). These findings provide a new perspective on the physiological influence of sulfoxaflor stress in honeybees.

Zuogui-Jiangtang-Qinggan-Fang alleviates high-fat diet-induced type 2 diabetes mellitus with non-alcoholic fatty liver disease by modulating gut microbiome-metabolites-short chain fatty acid composition

Non-alcoholic fatty liver disease (NAFLD) pathogenesis is affected by dysbiosis of the gut microbiome and the metabolites it generates. Therefore, restoring the equilibrium between the gut microbiome and the generated metabolites may have therapeutic potential for the syndrome. Zuogui Jiangtang Qinggan Fang (ZGJTQGF) is a Chinese herbal formulation used clinically to treat type 2 diabetic mellitus (T2DM) and fatty liver disease. However, its pharmacological mechanisms have not been well characterized. This work aimed to evaluate the hepatoprotective mechanism of ZGJTQGF in T2DM with NAFLD mice by incorporating gut microbiota, short-chain fatty acids（SCFAs）, and metabolomic analysis, and then to provide strong support for clinical treatment of T2DM with NAFLD. The sequencing of 16 S rRNA revealed that ZGJTQGF therapy modified the composition and abundance of the gut microbiome, raised the level of SCFAs, and restored the intestinal mucosal barrier. The non-targeted metabolomic analysis of liver tissues identified 212 compounds, of which108 were differentially expressed between the HFD and ZGJTQGF groups. Moreover, L-glutamic acid, L-Phenylalanine, Glycine, Taurine, Deoxycholic acid, and citric acid levels were also considerably altered by ZGJTQGF. Our findings suggest that ZGJTQGF ameliorates HFD-induced hepatic steatosis by modulating the gut microbiota composition and its metabolites and boosting the levels of SCFAs. More notably, ZGJTQGF may be a promising medication for preventing and treating NAFLD.

Data-driven identification of plasma metabolite clusters and metabolites of interest for potential detection of early-stage non-small cell lung cancer cases versus cancer-free controls

BACKGROUND

Metabolomics is a potential means for biofluid-based lung cancer detection. We conducted a non-targeted, data-driven assessment of plasma from early-stage non-small cell lung cancer (ES-NSCLC) cases versus cancer-free controls (CFC) to explore and identify the classes of metabolites for further targeted metabolomics biomarker development.

METHODS

Plasma from 250 ES-NSCLC cases and 250 CFCs underwent ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) in positive and negative electrospray ionization (ESI) modes. Molecular feature extraction, formula generation, and find-by-ion tools annotated metabolic entities. Analysis was restricted to endogenous metabolites present in ≥ 80% of samples. Unsupervised hierarchical cluster analysis identified clusters of metabolites. The metabolites with the strongest correlation with the principal component of each cluster were included in logistic regression modeling to assess discriminatory performance with and without adjustment for clinical covariates.

RESULTS

A total of 1900 UHPLC-QTOF-MS assessments identified 1667 and 2032 endogenous metabolites in the ESI-positive and ESI-negative modes, respectively. After data filtration, 676 metabolites remained, and 12 clusters of metabolites were identified from each ESI mode. Multivariable logistic regression using the representative metabolite from each cluster revealed effective classification of cases from controls with overall diagnostic accuracy of 91% (ESI positive) and 94% (ESI negative). Metabolites of interest identified for further targeted analysis include the following: 1b, 3a, 12a-trihydroxy-5b-cholanoic acid, pyridoxamine 5'-phosphate, sphinganine 1-phosphate, gamma-CEHC, 20-carboxy-leukotriene B4, isodesmosine, and 18-hydroxycortisol.

CONCLUSIONS

Plasma-based metabolomic detection of early-stage NSCLC appears feasible. Further metabolomics studies targeting phospholipid, steroid, and fatty acid metabolism are warranted to further develop noninvasive metabolomics-based detection of early-stage NSCLC.

Authenticity and traceability of goat milk: Molecular mechanism of β-carotene biotransformation and accessibility

The efficiently extraction and accurately quantify of β-carotene and its metabolites are crucial for authenticity and traceability in goat milk. Nevertheless, its reliability can be largely improved. In this study, meticulously designed native ESI-MS, fluorescence spectroscopy and molecular docking in combination with cold-induced acetonitrile aqueous two-phase separation system weaken the interaction between β-lactoglobulin and β-carotene metabolites and realized the efficiently extraction. Furthermore, established non-targeted quantitative metabolomics with optimal ion source and variable data-independent acquisition minimized the matrix effects and potential ion suppression. Validated atmospheric pressure chemical ionization-ultra high performance liquid chromatography-Orbitrap method showed that β-carotene as distinctive biomarker in cow milk, and retinol, retinaldehyde, retinoic acid and abscisic acid in goat milk. Collectively, the proposed method is a powerful tool to detect cow adulteration risks in goat milk samples and provides valuable information for availability on authenticity of goat milk.

Molecular response of Anoxybacillus sp. PDR2 under azo dye stress: An integrated analysis of proteomics and metabolomics

Treating azo dye wastewater using thermophilic bacteria is considered a more efficient bioremediation strategy. In this study, a thermophilic bacterial strain, Anoxybacillus sp. PDR2, was regarded as the research target. This strain was characterized at different stages of azo dye degradation by using TMT quantitative proteomic and non-targeted metabolome technology. A total of 165 differentially expressed proteins (DEPs) and 439 differentially metabolites (DMs) were detected in comparisons between bacteria with and without azo dye. It was found that Anoxybacillus sp. PDR2 can degrade azo dye Direct Black G (DBG) through extracellular electron transfer with glucose serving as electron donors. Most proteins related to carbohydrate metabolism, including acetoacetate synthase, and malate synthase G, were overexpressed to provide energy. The bacterium can also self-synthesize riboflavin as a redox mediator of in vitro electron transport. These results lay a theoretical basis for industrial bioremediation of azo dye wastewater.

Integrated 16S rDNA, metabolomics, and TNF-α/NF-κB signaling pathway analyses to explain the modulatory effect of Poria cocos aqueous extract on anxiety-like behavior

BACKGROUND

Poria cocos is an ancient medicine and modern functional food, which exerts excellent effects on anxiety, although its mechanism is unknown.

PURPOSE

To explore the mechanisms of the aqueous extract of P. cocos (PCD) in ameliorating anxiety-like behavior caused by chronic sleep deprivation (CSD).

METHODS

PCD chemical composition was analyzed by UPLC-QTOF-MS/MS. A CSD rat model was established over 21 days. We examined the effects and mechanisms after 10 days of CSD using open-field tests (OFTs), enzyme-linked immunosorbent assays, 16S rDNA, non-targeted metabolomics, and Western blot analyses.

RESULTS

Sixty-two triterpenoids were identified in PCD. CSD-induced anxiety-like behavior was significantly attenuated by PCD treatment. PCD improved hypothalamic neurotransmitters, decreased proinflammatory cytokines, and depressed the proteins expression of tumor necrosis factor (TNF)-α/nuclear factor (NF)-κB signaling pathway. The full-length 16S rDNA sequence of bacterial cells was also sequenced by high-throughput analysis. CSD caused significant changes in the intestinal flora. PCD improved the species diversity and bacterial abundance in the intestines of rats with anxiety. Metabolomics analysis indicated that 12 PCD-related metabolites in serum and 32 PCD-related metabolites in feces were identified, respectively. Metabolite analysis in serum, PCD treatment affected taurine, hypotaurine, cysteine, methionine, glycine, serine, and threonine metabolism, among others. Metabolite analysis in feces showed significant effects of PCD treatment on the metabolism of vitamin B6, tyrosine, drugs, and glycerophospholipid. Additionally, the correlation analysis of heatmaps showed a tight relationship between inflammatory factors, metabolic parameters, and gut microbial phylotypes.

CONCLUSIONS

PCD relieved anxiety by regulating intestinal flora, regulating metabolic disorders, and inhibiting inflammatory pathways in chronic sleep-deprived rats.

Blood metabolic and physiological profiles of Bama miniature pigs at different growth stages

Background

Bama miniature pigs aged between six (6 M) and twelve months (12 M) are usually used in human medical research as laboratory pigs. However, the difference in serum metabolic profiles from 6 to 12 M-old pigs remains unclear. This study aimed to identify the metabolic and physiological profiles present in the blood to further explain changes in Bama miniature pig growth. We collected blood samples from 6 M-, eight-month- (8 M-), ten-month- (10 M-), and 12 M-old healthy Guangxi Bama miniature pigs. A total of 20 blood physiological indices (BPIs) were measured: seven for white blood cells, eight for red blood cells, and five for platelet indices. Liquid chromatography and mass spectrometry-based non-targeted metabolomic approaches were used to analyze the difference in metabolites. The associations between the differences were calculated using Spearman correlations with Benjamini–Hochberg adjustment. The 100 most abundant differential metabolites were selected for analysis of their metabolic profiles.

Results

There were no significant differences in BPIs at different ages, but the mid cell ratio and red blood cell number increased with age. Seven BPIs in Bama miniature pigs were closer to human BPIs than to mouse BPIs. A total of 14 and 25 significant differential metabolites were identified in 6 M vs. 12 M and 8 M vs. 12 M, respectively. In total, 9 and 18 amino acids and their derivatives showed significantly lower concentrations in 6 M- and 8 M-old pigs than in 12 M-old pigs. They were identified as the core significantly different metabolites between the age groups 6 M vs. 12 M and 8 M vs. 12 M. Half of the enriched pathways were the amino acids metabolism pathways. The concentration of six amino acids (dl-tryptophan, phenylacetylglycine, muramic acid, N-acetylornithine, l(−)-pipecolinic acid, and creatine) and their derivatives increased with age. A total of 61 of the top 100 most abundant metabolites were annotated. The metabolic profiles contained 14 amino acids and derivatives, six bile acids and derivatives, 19 fatty acids and derivatives, and 22 others. The concentrations of fatty acids and derivatives were found to be inversely proportional to those of amino acids and derivatives.

Conclusion

These findings suggest high levels of MID cell ratio, red blood count, and amino acids in 12 M-old pigs as indicators for improved body function over time in Bama miniature pigs, similar to those in human development. This makes the pig a more suitable medical model organism than the mouse. The results of this study are limited to the characteristics of blood metabolism in the inbred Bama miniature pigs, and the effects of impacting factors such as breed, age, sex, health status and nutritional level should be considered when studying other pig populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40813-022-00278-7.

Metabolomics analysis of three Artemisia species in the Tibet autonomous region of China

BACKGROUND

The Artemisia species are widely distributed around the world, and have found important usage in traditional medicinal practice. This study was designed to investigate the metabolites of Tibetan Artemisia species and understand the metabolic pathways.

METHODS

The metabolites from three Artemisia species in Tibet, were analyzed using LC-MS/MS. The differential metabolites were classified and analyzed by principal component analysis (PCA), partial least squares analysis and hierarchical clustering. KEGG Pathway enrichment analysis was used to identify the key metabolic pathways involved in the differential metabolites of three Artemisia species.

RESULT

The metabolites of three Artemisia species were analyzed. Under the positive ion mode in LC-MS/MS, 262 distinct metabolites were differentially detected from Artemisia sieversiana and Artemisia annua, 312 differential metabolites were detected from Artemisia wellbyi and Artemisia sieversiana, 306 differential metabolites were screened from Artemisia wellbyi and Artemisia annua. With the negative ion mode, 106 differential metabolites were identified from Artemisia sieversiana and Artemisia annua, 131 differential metabolites were identified from Artemisia wellbyi and Artemisia sieversiana,133 differential metabolites were differentially detected from Artemisia wellbyi and Artemisia annua. The selected differential metabolites were mainly organic acids and their derivatives, ketones, phenols, alcohols and coumarins. Among these natural compounds, artemisinin, has the highest relative content in Artemisia annua.

CONCLUSIONS

This is the first reported attempt to comparatively determine the types of the metabolites of the three widely distributed Artemisia species in Tibet. The information should help medicinal research and facilitate comprehensive development and utilization of Artemisia species in Tibet.

Non-targeted metabolomic profiling of filamentous cyanobacteria Aphanizomenon flos-aquae exposed to a concentrated culture filtrate of Microcystis aeruginosa

Microcystis and Aphanizomenon are two toxic cyanobacteria genera, which frequently cause blooms in freshwater lakes. In some cases, succession of these two genera was observed in natural water bodies. Among the diverse factors contributing to such succession of dominant cyanobacterial genera, an allelopathic effect was proposed to be involved after the growth inhibitory effect of several Microcystis species on A. flos-aquae was investigated. However, the response of target species exposed to Microcystis are poorly described. In the present study, we used two toxic cyanobacteria strains, Aphanizomenon flos-aquae (Aph1395) and Microcystis aeruginosa strain 905 (Ma905) as research subjects. Aph1395 was inhibited with a necessarily concentrated culture filtrate of Ma905 (MA905-SPE), and the response of the inhibited Aph1395 cells was explored via non-targeted metabolomic profiling. In total, 3735 features were significantly different in the Aph1395 treated with Ma905-SPE vs. those treated with BG11 medium. Among them, the annotations of 146 differential features were considered to be confident via MS/MS spectrum matching analysis. Based on the reported physiological functions of the annotated differential features, we proposed a putative model that in the growth-inhibited Aph1395, a suite of increased or decreased features with activities in apoptosis, growth inhibition, and stress response processes contributed to, or defended against, the allelopathic effect caused by Ma905. Our findings provide insights into the interaction between the bloom forming cyanobacterial species that share the same ecological environment.

Fecal metabolomic analysis of rabbits infected with Eimeria intestinalis and Eimeria magna based on LC-MS/MS technique

Rabbit coccidiosis is a common parasitic disease leading to economic losses in the rabbit industry. The intestinal flora plays a key role in pathogenesis of coccidiosis, and fecal metabolome mediates host-microbiome interactions as a functional readout of the gut microbiome. In this study, the E. intestinalis-infected and E. magna-infected rabbit models were established to investigate metabolic alterations and metabolic pathways based on LC-MS/MS technique for the first time. Multivariate OPLS-DA analysis was performed to explore differential metabolites. In total, 288 metabolites were detected from infected and uninfected rabbits. The level of 33 metabolites increased and 4 decreased in rabbits infected with E. intestinalis. Eight pathways were significantly perturbed during E. intestinalis infection including biosynthesis of unsaturated fatty acids, fatty acid biosynthesis, etc. After rabbits infected with E. magna, 13 metabolites were altered and 7 metabolic pathways were dysregulated. These metabolites and metabolic pathways were mainly involved in tuberculosis, parathyroid hormone synthesis, etc. Besides, 25 metabolites differed in abundance between E. intestinalis infection group and E. magna infection group, the major perturbed metabolic pathways were lipid metabolism and endocrine system, respectively. In general, it is confirmed that E. intestinalis and E. magna infection destroyed the intestinal flora, which caused corresponding changes in metabolites, and provide novel insights into the molecular mechanisms of rabbit-parasite interactions.

Integration of transcriptomics and non-targeted metabolomics reveals the underlying mechanism of follicular atresia in Chinese buffalo

Follicular atresia is a complex physiological process, which results in the waste of follicles and oocytes from the ovary. Elucidating the physiological mechanism of follicular atresia will hopefully reverse the fate of follicles, thereby improve the reproductive efficiency of female animals. However, there are still many gaps to be filled during the follicular atresia process. In this study, we first comprehensively summarized and compared a variety of methods to classify Chinese buffalo follicles with different extent of atresia. Then follicular fluid and granulosa cells from the corresponding follicles with different extent of atresia were collected for non-targeted metabolomics and transcriptomics analysis, respectively. After the detection and analysis of 129 follicles, a reasonable classification standard was formed: on the basis of morphological classification, the relative concentrations of estradiol (E2) and progesterone (PROG) in the follicular fluid were determined, follicles with an estradiol-to-progesterone (E2/PROG) ratio >5 were classified as healthy follicles (HF), 1≤ E2/PROG ≤5 as early atretic follicles (EF) and E2/PROG <1 as late atretic follicles (LF). Correspondingly, follicles with granulosa cells apoptosis rate less than 15 % were divided into HF, 15%-25% were classified as EF and more than 25 % were classified as LF. The integration analysis of non-targeted metabolomics and transcriptomics highlights the following three aspects: (1) Atresia seriously damaged the lipid metabolism homeostasis of follicle, in which PPARγ play important roles. (2) Energy metabolism and nucleotide metabolism of atretic follicles were inhibited. (3) Bilirubin is involved in follicular atresia, and it may be the main force to prevent lipid peroxidation in follicular cells. In summary, results of this study provide new understanding of the molecular mechanisms of Chinese buffalo follicular atresia.

Investigating the role of endogenous estrogens, hormone replacement therapy, and blockade of estrogen receptor-α activity on breast metabolic signaling

Purpose

Menopause is associated with an increased risk of estrogen receptor-positive (ER +) breast cancer. To characterize the metabolic shifts associated with reduced estrogen bioavailability on breast tissue, metabolomics was performed from ovary-intact and ovariectomized (OVX) female non-human primates (NHP). The effects of exogenous estrogen administration or estrogen receptor blockade (tamoxifen treatment) on menopause-induced metabolic changes were also investigated.

Methods

Bilateral ovariectomies were performed on female cynomolgus macaques (Macaca fascicularis) to model menopause. OVX NHP were then divided into untreated (n = 13), conjugated equine estrogen (CEE)-treated (n= 13), or tamoxifen-treated (n = 13) subgroups and followed for 3 years. Aged-matched ovary-intact female NHP (n = 12) were used as a premenopausal comparison group. Metabolomics was performed on snap-frozen breast tissue.

Results

Changes in several different metabolic biochemicals were noted, particularly in glucose and fatty acid metabolism. Specifically, glycolytic, Krebs cycle, acylcarnitines, and phospholipid metabolites were elevated in breast tissue from ovary-intact NHP and OVX + CEE in relation to the OVX and OVX + tamoxifen group. In contrast, treatment with CEE and tamoxifen decreased several cholesterol metabolites, compared to the ovary-intact and OVX NHP. These changes were accompanied by elevated bile acid metabolites in the ovary-intact group.

Conclusion

Alterations in estrogen bioavailability are associated with changes in the mammary tissue metabolome, particularly in glucose and fatty acid metabolism. Changes in these pathways may represent a bioenergetic shift in gland metabolism at menopause that may affect breast cancer risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06354-w.

Taurine reduction associated with heart dysfunction after real-world PM2.5 exposure in aged mice

Ambient PM_2.5 has been proved to be an independent risk factor for cardiovascular diseases; however, little information is available on the age-dependent effects of PM_2.5 on the cardiovascular system and the underlying mechanisms following chronic exposure. In this study, multi-aged mice were exposed to PM_2.5 via the newly developed real-ambient PM_2.5 exposure system to investigate age-related effects on the heart after long-term exposure. First, the chemical and physical properties of PM_2.5 used in the exposure system were analyzed. The heart rate of conscious mice was recorded, and results showed that exposure of aged mice to PM_2.5 for 26 weeks significantly increased heart rate. Histological analysis and ELISA assays indicated that aged mice were more sensitive to PM_2.5 exposure in terms of inducing cardiac oxidative stress and inflammation. Furthermore, untargeted metabolomics revealed that taurine was involved with the PM_2.5-induced cardiac dysfunction. The reduced taurine concentration in the heart was examined by LC-MS and imaging mass spectrometry; it may be due to the increased p53 expression level, ROS and inflammatory cytokines. These results emphasize the age-dependent effects of PM_2.5 on the cardiovascular system and suggest that taurine may be the novel cardiac effect target for PM_2.5-induced heart dysfunction in the aged.

Non-targeted metabolomic analysis predicts the therapeutic effects of exenatide on endothelial injury in patients with type 2 diabetes

AIMS

We aimed to investigate whether treatment with exenatide could ameliorate endothelial injury in patients with type 2 diabetes mellitus (T2DM), and to identify biomarkers for predicting amelioration of the endothelial injury induced by the treatment.

METHODS

Ninety-three patients with T2DM were recruited and treated with exenatide for 16 weeks. Enzyme-linked immunosorbent assays were performed at baseline and after the treatment to measure serum levels of endothelial injury markers, including soluble thrombomodulin (sTM). Patients were categorized as responders (n = 47) or non-responders (n = 46) based on median changes in their sTM levels. Serum levels of metabolites at baseline were measured with non-targeted liquid chromatography-mass spectrometry. The results obtained were evaluated with multivariate analysis.

RESULTS

Treatment with exenatide for 16 weeks resulted in reduced body weight and improved levels of fasting plasma glucose, 2-hour postprandial plasma glucose, and HbA1c in patients with T2DM (all P < 0.05). Compared with baseline, serum levels of endothelial injury markers including sTM were significantly lowered after the treatment. Metabolites presented at significantly different levels in responders versus non-responders were considered as biomarkers for a therapeutic response of sTM to the exenatide treatment. Among those identified, 4-hydroxyproline and 12-oxo-9(Z)-dodecenoic acid were found to correlate most closely with the exenatide-induced endothelial protection response. The specificity and sensitivity of the multi-metabolite signature model contained higher 4-hydroxyproline and lower 12-oxo-9(Z)-dodecenoic acid were 53.3% and 92.3%, respectively, and the area under receiver operating characteristic curve was 69.2% (P < 0.001).

CONCLUSIONS

Treatment with exenatide for 16 weeks ameliorates endothelial injury in patients with T2DM. Endothelial protection benefit from exenatide treatment was effectively predicted by the specific metabolomic combination of higher 4-hydroxyproline and lower 12-oxo-9(Z)-dodecenoic acid.

Metabolomics analysis reveals potential mechanisms of phenolic accumulation in lettuce (Lactuca sativa L.) induced by low nitrogen supply

The roles of nitrogen availability in determining the phenolic accumulation of vegetables have been widely studied, but the underlying mechanism involved remains unknown. Thus, primary and secondary metabolites profiling of lettuce leaves were performed using non-targeted metabolomics analysis. The results showed that carbon metabolism, amino acid metabolism, and phenolic biosynthesis metabolism in lettuce were significantly affected by low nitrogen supply (LN). The phenolic content was significantly increased in LN-treated lettuce, indicating that the activated phenolic biosynthesis was triggered by the LN treatment. The reduced citrate cycle and enhanced glucose and sucrose content suggested there is a relative excess of carbon resources in LN-treated lettuce. In addition, the decreased nitrogen-rich amino acids (glutamine and aspartate acid) and the maintained phenylalanine content indicated the redirection of nitrogen resources to phenylalanine biosynthesis. Meanwhile, no significant changes of chlorophyll content were observed in LN-treated lettuce leaves. The LN-treated lettuce showed lower glutamine synthetase activity but higher glutamate synthase activity compared to control. These findings together suggest that LN treatment may increase the phenolic accumulation in lettuce by effectively redirecting more carbon and nitrogen resources to the phenolic biosynthesis pathway.

Integrated metabolomics and transcriptomics study of traditional herb Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao reveals global metabolic profile and novel phytochemical ingredients

BACKGROUND

Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao is one of the most common herbs widely used in South and East Asia, to enhance people's health and reinforce vital energy. Despite its prevalence, however, the knowledge about phytochemical compositions and metabolite biosynthesis in Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao is very limited.

RESULTS

An integrated metabolomics and transcriptomics analysis using state-of-the-art UPLC-Q-Orbitrap mass spectrometer and advanced bioinformatics pipeline were conducted to study global metabolic profiles and phytochemical ingredients/biosynthesis in Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao. A total of 5435 metabolites were detected, from which 2190 were annotated, representing an order of magnitude increase over previously known. Metabolic profiling of Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao tissues found contents and synthetic enzymes for phytochemicals were significantly higher in leaf and stem in general, whereas the contents of the main bioactive ingredients were significantly enriched in root, underlying the value of root in herbal remedies. Using integrated metabolomics and transcriptomics data, we illustrated the complete pathways of phenylpropanoid biosynthesis, flavonoid biosynthesis, and isoflavonoid biosynthesis, in which some were first reported in the herb. More importantly, we discovered novel flavonoid derivatives using informatics method for neutral loss scan, in addition to inferring their likely synthesis pathways in Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao.

CONCLUSIONS

The current study represents the most comprehensive metabolomics and transcriptomics analysis on traditional herb Astragalus membranaceus Bge. var. mongolicus (Bge.) Hsiao. We demonstrated our integrated metabolomics and transcriptomics approach offers great potentials in discovering novel metabolite structure and associated synthesis pathways. This study provides novel insights into the phytochemical ingredients, metabolite biosynthesis, and complex metabolic network in herbs, highlighting the rich natural resource and nutritional value of traditional herbal plants.

The formation process of green substances in Chrysanthemum morifolium tea

One interesting phenomenon of Chrysanthemum morifolium tea is its formation of a green or dark green color after hours of brewing, and it is important to study the compounds that form this color and whether they might be involved in health benefits. Non-targeted metabolomics could clearly distinguish between green and non-green species by sparse partial least squares discriminant analysis (sPLS-DA) and heat-mapping. We found that the pH was the primary factor in the formation of the green color. Two green precursors (GP1 and GP2) were separated and purified with preparative HPLC. FT-IR analysis and the saccharide content analysis showed that GP1 had the typical characteristics of saccharides. GP2 was identified as chlorogenic acid by ESI-Q-TOF/MS and NMR. We raised the formation process of green substances was caused by the hydrolysates of chlorogenic acid reacting with glycosides or groups attached to the saccharides, which suggests a new mechanism for color-forming reactions.

Lipidome signatures of metastasis in a transgenic mouse model of sonic hedgehog medulloblastoma

Medulloblastoma (MB), the most common malignant pediatric brain tumor, has high propensity to metastasize. Currently, the standard treatment for MB patients includes radiation therapy administered to the entire brain and spine for the purpose of treating or preventing against metastasis. Due to this aggressive treatment, the majority of long-term survivors will be left with permanent and debilitating neurocognitive impairment, for the 30-40% patients that fail to respond to treatment, all will relapse with terminal metastatic disease. An understanding of the underlying biology that drives MB metastasis is lacking, and is critically needed in order to develop targeted therapeutics for its prevention. To examine the metastatic biology of sonic hedgehog (SHH) MB, the human MB subgroup with the worst clinical outcome in children, we first generated a robust SmoA1-Math-GFP mouse model that reliably reproduces human SHH MB whereby metastases can be visualized under fluorescence microscopy. Lipidome alterations associated with metastasis were then investigated by applying ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) under positive ionization mode to primary tumor samples collected from mice without (n = 18) and with (n = 7) metastasis. Thirty-four discriminant lipids associated with SHH MB metastasis were successfully annotated, including ceramides (Cers), sphingomyelins (SMs), triacylglycerols (TGs), diacylglycerols (DGs), phosphatidylcholines (PCs), and phosphatidic acids (PAs). This study provides deeper insights into dysregulations of lipid metabolism associated with SHH MB metastatic progression, and thus serves as a guide toward novel targeted therapies.

flower core collections using UPLC-QTOF/MS-based non-targeted metabolomics

Background

In the Chinese health care industry, male Eucommia ulmoides Oliv. flowers are newly approved as a raw material of functional food. Core collections have been constructed from conserved germplasm resources based on phenotypic traits and molecular markers. However, little is known about these collections’ phytochemical properties. This study explored the chemical composition of male E. ulmoides flowers, in order to provide guidance in the quality control, sustainable cultivation, and directional breeding of this tree species.

Methods

We assessed the male flowers from 22 core collections using ultra-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) non-targeted metabolomics, and analyzed them using multivariate statistical methods including principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least squares discriminant analysis (OPLS-DA).

Results

We annotated a total of 451 and 325 metabolites in ESI+ and ESI− modes, respectively, by aligning the mass fragments of the secondary mass spectra with those in the database. Four chemotypes were well established using the ESI+ metabolomics data. Of the 29 screened biomarkers, 21, 6, 19, and 5 markers corresponded to chemotypes I, II, III, and IV, respectively. More than half of the markers belonged to flavonoid and amino acid derivative classes.

Conclusion

Non-targeted metabolomics is a suitable approach to the chemotype classification and biomarker screening of male E. ulmoides flower core collections. We first evaluated the metabolite profiles and compositional variations of male E. ulmoides flowers in representative core collections before establishing possible chemotypes and significant biomarkers denoting the variations. We used genetic variations to infer the metabolite compositional variations of male E. ulmoides flower core collections instead of using the geographical origins of the germplasm resources. The newly proposed biomarkers sufficiently classified the chemotypes to be applied for germplasm resource evaluation.

Aquatic macroinvertebrates under stress: Bioaccumulation of emerging contaminants and metabolomics implications

The current knowledge on bioaccumulation of emerging contaminants (ECs) in aquatic invertebrates exposed to the realistic environmental concentrations is limited. Even less is known about the effects of chemical pollution exposure on the metabolome of aquatic invertebrates. We conducted an in situ translocation experiment with passive filter-feeding caddisfly larvae (Hydropsyche sp.) in an effluent-influenced river in order to i) unravel the bioaccumulation (and recovery) dynamics of ECs in aquatic invertebrates, and ii) test whether exposure to environmentally realistic concentrations of ECs will translate into metabolic profile changes in the insects. The experiment was carried out at two sites, upstream and downstream of the discharge of an urban wastewater treatment plant effluent. The translocated animals were collected at 2-week intervals for 46 days. Both pharmaceuticals and endocrine disrupting compounds (EDCs) were detected in water (62 and 7 compounds, respectively), whereas in Hydropsyche tissues 5 EDCs accumulated. Overall, specimens from the upstream site translocated to the impacted site reached higher ECs concentrations in their tissues, as a reflection of the contaminants' water concentrations. However, bioaccumulation was a temporary process susceptible to change under lower contaminant concentrations. Non-targeted metabolite profiling detected fine metabolic changes in translocated Hydropsyche larvae. Both translocations equally induced stress, but it was higher in animals translocated to the impacted site.

Comparative non-targeted metabolomic analysis reveals insights into the mechanism of rice yellowing

Yellowing of rice during storage is a highly concerned issue for managing rice quality whereas the yellowing mechanism is not clearly elucidated so far. Thus, the comparative untargeted metabolomic analysis was performed in this study. The results revealed that glycolysis pathway and tricarboxylic acid cycle (TCA) were significantly enhanced in yellowed rice, indicating the activated energy metabolism was trigged during the yellowing process. In addition, the increased aromatic compounds (4-hydroxycinnamic acid and benzoic acid) and their precursors (phenylalanine, tyrosine) suggested the activation of shikimate-phenylpropanoid biosynthesis in yellowed rice, which is an antioxidant defense related pathway. In particular, the pathways involved in the metabolism of glutamate and arginine also significantly altered in yellowed rice. Therefore, the enriched pathways of increased amino acids, sugars, sugar alcohols, and intermediates of the TCA cycle during yellowing process are proposed to be associated with the response of heat and dry induced by the yellowing process.

Metabolite signatures of grasspea suspension-cultured cells illustrate the complexity of dehydration response

This represents the first report deciphering the dehydration response of suspension-cultured cells of a crop species, highlighting unique and shared pathways, and adaptive mechanisms via profiling of 330 metabolites. Grasspea, being a hardy legume, is an ideal model system to study stress tolerance mechanisms in plants. In this study, we investigated the dehydration-responsive metabolome in grasspea suspension-cultured cells (SCCs) to identify the unique and shared metabolites crucial in imparting dehydration tolerance. To reveal the dehydration-induced metabolite signatures, SCCs of grasspea were exposed to 10% PEG, followed by metabolomic profiling. Chromatographic separation by HPLC coupled with MRM-MS led to the identification of 330 metabolites, designated dehydration-responsive metabolites (DRMs), which belonged to 28 varied functional classes. The metabolome was found to be constituted by carboxylic acids (17%), amino acids (13.5%), flavonoids (10.9%) and plant growth regulators (10%), among others. Pathway enrichment analysis revealed predominance of metabolites involved in phytohormone biosynthesis, secondary metabolism and osmotic adjustment. Exogenous application of DRMs, arbutin and acetylcholine, displayed improved physiological status in stress-resilient grasspea as well as hypersensitive pea, while administration of lauric acid imparted detrimental effects. This represents the first report on stress-induced metabolomic landscape of a crop species via a suspension culture system, which would provide new insights into the molecular mechanism of stress responses and adaptation in crop species.