DMMIC derivatization-assisted liquid chromatography-mass spectrometry method for metabolite profiling of the glutathione anabolic pathway in esophageal cancer tissues and cells

In this work,a new pyrylium derivatization-assisted liquid chromatography-mass spectrometry(LC-MS)method was developed for metabolite profiling of the glutathione anabolic pathway(GAP)in cancer tissues and cells.The pyrylium salt of 6,7-dimethoxy-3-methyl isochromenylium tetrafluoroborate(DMMIC)was used to label the amino group of metabolites,and a reductant of dithiothreitol(DTT)was employed to stabilize the thiol group.By combining DMMIC derivatization with LC-MS,it was feasible to quantify the 13 main metabolites on the GAP in complex biological samples,which had good linearity(R^(2)=0.99810.9999),precision(interday precision of 1.6%e19.0%and intraday precision of 1.4%e19.8%)and accuracy(83.4%-115.7%).Moreover,the recovery assessments in tissues(82.5%e107.3%)and in cells(98.1%e118.9%)with GSH-^(13)C2,^(15)N,and Cys-^(15)N demonstrated the reliability of the method in detecting tissues and cells.Following a methodological evaluation,the method was applied successfully to investigate difference in the GAP between the carcinoma and para-carcinoma tissues of esophageal squamous cell carcinoma(ESCC)and the effect of p-hydroxycinnamaldehyde(CMSP)on the GAP in KYSE150 esophageal cancer cells.The results demonstrate that the developed method provides a promising new tool to elucidate the roles of GAP in physiological and pathological processes,which can contribute to research on drugs and diseases.

Metabolite profiling and antidiabetic attributes of ultrasonicated leaf extracts of Conocarpus lancifolius

Objective:To profile the secondary metabolites and to evaluate the antidiabetic potential of hydroethanolic leaf extracts of Conocarpus lancifolius.Methods:The various hydroethanolic extracts of Conocarpus lancifolius leaf were prepared by ultrasonication assisted freezedrying.Total phenolic contents,flavonoid contents,antioxidant activity,α-glucosidase andα-amylase inhibitions of leaf extracts were determined.The metabolite profiling was accomplished by UHPLC-Q-TOF-MS/MS analysis.The antidiabetic assessment of the most potent extract was carried out by measuring the hypoglycemic and hypolipidemic effect in the high fat diet-fed diabetic albino mice.The blood glucose level,haemoglobin,total cholesterol,high-density lipoproteins(HDL)and low-density lipoproteins(LDL)were determined.Results:The 60%ethanolic extract exhibited the highest phenolic and flavonoid contents of(349.39±2.13)mg GAE/g dry extract and(116.95±2.34)mg RE/g dry extracts,respectively,and the highest DPPH scavenging activity with an IC50 value of(32.87±1.11)μg/mL.The IC50 values forα-glucosidase andα-amylase inhibitions were(38.64±0.93)μg/mL and(44.80±1.57)μg/mL,respectively.UHPLC-Q-TOF-MS/MS analysis confirmed the presence of gallic acid,ellagic acid,corilagin,kaempherol-3-O-rutinoside,caffeic acid derivative,isorhamnetin and galloyl derivatives in the 60%ethanolic extract.Plant extract at a dose of 450 mg/kg body weight reduced blood glucose level,total cholesterol,LDL and HDL,and increased haemoglobin in alloxan-induced diabetic mice,Conclusions:Conocarpus lancifolius leaves are proved as a good source of biologically functional metabolites and possess antidiabetic activity which may be further explored to treat diabetes.

Anti-obesity effect and UHPLC-QTOF-MS/MS based metabolite profiling of Solanum nigrum leaf extract

Objective:To evaluate the antioxidant potential and pancreatic lipase inhibitory action of optimized hydroethanolic extracts of Solanum nigrum.Methods:Optimized extraction for maximum recovery of metabolites was performed using a combination of freeze-drying and ultrasonication followed by determination of antioxidant and antiobesity properties.The ultra-high performance liquid chromatography equipped with mass spectrometry was used to analyze metabolite profiling of Solanum nigrum.Computational studies were performed using molecular docking and electrostatic potential analysis for individual compounds.The hypolipidemic potential of the most potent extract was assessed in the obese mice fed on fat rich diet.Results:The 80%hydroethanolic extract exhibited the highest extract yield,total phenolic contents,total flavonoid contents along with the strongest 2,2-diphenyl-1-picrylhydrazyl scavenging activity,total antioxidant power,and pancreatic lipase inhibitory properties.The 80%hydroethanolic extract not only regulated the lipid profile of obese mice but also restricted the weight gain in the liver,kidney,and heart.The 80%hydroethanolic extract also reduced alanine transaminase and aspartate transaminase concentrations in serum.The effects of plant extract at 300 mg/kg body weight were quite comparable with the standard drug orlistat.Conclusions:Solanum nigrum is proved as an excellent and potent source of secondary metabolites that might be responsible for obesity mitigation.

Deciphering chemical and metabolite profiling of Chang-Kang-Fang by UPLC-Q-TOF-MS/MS and its potential active components identification

Chang-Kang-Fang(CKF)formula,a Traditional Chinese Medicine(TCM)prescription,has been widely used for the treatment of irritable bowel syndrome(IBS).However,its potential material basis and underlying mechanism remain elusive.Therefore,this study employed an integrated approach that combined ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q/TOF-MS)with network pharmacology to systematically characterize the phytochemical components and metabolites of CKF,as well as elucidating its underlying mechanism.Through this comprehensive analysis,a total of 150 components were identified or tentatively characterized within the CKF formula.Notably,six N-acetyldopamine oligomers from Cicadae Periostracum and eight resin glycosides from Cuscutae Semen were characterized in this formula for the first time.Meanwhile,149 xenobiotics(58 prototypes and 91 metabolites)were detected in plasma,urine,feces,brain,and intestinal contents,and the in vivo metabolic pathways of resin glycosides were elaborated for the first time.Furthermore,network pharmacology and molecular docking analyses revealed that alkaloids,flavonoids,chromones,monoterpenes,N-acetyldopamine dimers,p-hydroxycinnamic acid,and Cus-3/isomer might be responsible for the beneficial effects of CKF in treating IBS,and CASP8,MARK14,PIK3C,PIK3R1,TLR4,and TNF may be its potential targets.These discoveries offer a comprehensive understanding of the potential material basis and clarify the underlying mechanism of the CKF formula in treating IBS,facilitating the broader application of CKF in the field of medicine.

Deciphering Starch Quality of Rice Kernels Using Metabolite Profiling and Pedigree Network Analysis

The physiological properties of rice grains are immediately obvious to consumers. High-coverage metabolomic characterization of the rice diversity research set predicted a negative correlation between fatty acid and lipid levels and amylose/total starch ratio （amylose ratio）, but the reason for this is unclear. To obtain new insight into the relationships among the visual phenotypes of rice kernels, starch granule structures, amylose ratios, and metabolite changes, we investigated the metabolite changes of five Japonica cultivars with various amylose ratios and two knockout mutants （e 1, a Starch synthase Ilia （SSIIla）-deficient mutant and the SSIIla/starch branching enzyme （BE） double-knockout mutant 4019） by using mass spectrometry-based metabolomics techniques. Scanning electron microscopy clearly showed that the two mutants had unusual starch granule structures. The metabolomic compositions of two cultivars with high amylose ratios （Hoshiyutaka and Yumetoiro） exhibited similar patterns, while that of the double-knockout mutant, which has an extremely high amylose ratio, differed. Rice pedigree network analysis of the cultivars and the mutants provided insight into the association between metabolic-trait properties and their underlying genetic basis in rice breeding in Japan. Multidimensional scaling analysis revealed that the Hoshiyutaka and Yumetoiro cultivars were Indica-like, yet they are classified as Japonica subpopulations. Exploring metabolomic traits is a powerful way to follow rice genetic traces and breeding history.

Identification of metabolites of Radix Paeoniae Alba extract in rat bile, plasma and urine by ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry

Ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry （UPLC-Q-TOF/MS） was developed to identify the absorbed parent components and metabolites in rat bile, plasma and urine after oral administration of Radix Paeoniae Alba extract （RPAE）. A total of 65 compounds were detected in rat bile, plasma and urine samples, including 11 parent compounds and 54 metabolites. The results indicated that glucuronidation, hydroxylation and methylation were the major metabolic pathways of the components of RPAE. Furthermore, the results of this work demonstrated that UPLC-Q-TOF/MS combined with MetaboLynx？ software and mass defect filtering （MDF） could provide unique high throughput capabilities for drug metabolism study, with excellent MS mass accuracy and enhanced MSE data acquisition. With the MSE technique, both precursor and fragment mass spectra can be simultaneously acquired by alternating between high and low collision energy during a single chromatographic run.

Changes in the Non-targeted Metabolomic Profile of Three-year-old Toddlers with Elevated Exposure to Polycyclic Aromatic Hydrocarbons

Objective To investigate changes in the urinary metabolite profiles of children exposed to polycyclic aromatic hydrocarbons(PAHs)during critical brain development and explore their potential link with the intestinal microbiota.Methods Liquid chromatography-tandem mass spectrometry was used to determine ten hydroxyl metabolites of PAHs(OH-PAHs)in 36-month-old children.Subsequently,37 children were categorized into low-and high-exposure groups based on the sum of the ten OH-PAHs.Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used to identify non-targeted metabolites in the urine samples.Furthermore,fecal flora abundance was assessed by 16S rRNA gene sequencing using Illumina MiSeq.Results The concentrations of 21 metabolites were significantly higher in the high exposure group than in the low exposure group(variable importance for projection>1,P<0.05).Most of these metabolites were positively correlated with the hydroxyl metabolites of naphthalene,fluorine,and phenanthrene(r=0.336–0.531).The identified differential metabolites primarily belonged to pathways associated with inflammation or proinflammatory states,including amino acid,lipid,and nucleotide metabolism.Additionally,these distinct metabolites were significantly associated with specific intestinal flora abundances(r=0.34–0.55),which were mainly involved in neurodevelopment.Conclusion Higher PAH exposure in young children affected metabolic homeostasis,particularly that of certain gut microbiota-derived metabolites.Further investigation is needed to explore the potential influence of PAHs on the gut microbiota and their possible association with neurodevelopmental outcomes.

Postmortem Metabolite Profile Changes of Mud Crab(Scylla paramamosain)Under Different Storage Conditions

Mud crab(Scylla paramamosain)is one of the most consumed crabs in China.Generally,it is believed that dead mud crabs are not edible.Herein,we investigated the postmortem metabolite profile changes of the muscle and hepatopancreas of mud crab associated with storage method using nuclear magnetic resonance-based metabolomics coupled with multivariate data analysis.Our results showed that postmortem changes of trimethylamine,organic acids(lactate,formate,and succinate),as well as ATP and its breakdown products are closely affected by the storage method.These metabolites can be used as indicators for monitoring loss of crab freshness.Furthermore,dead mud crabs preserved an edible quality at least for 4 h at room temperature,12h on ice,and 16 d at−20℃,strongly suggesting that dead crab consumption quality should be determined by freshness.They shouldn’t be discarded without considering the effects of different storage conditions on their freshness.

Identification of key taste components in Baccaurea ramiflora Lour.fruit using non-targeted metabolomics

Among the numerous fruit species of Baccaurea ramiflora Lour.,‘LR’(white flesh)and‘BR’(pink flesh)are two kinds of local strains with high edibility.In order to study the metabolic causes of taste differences,we performed the non-targeted metabonomics analysis of‘LR’and‘BR’using LC-MS/MS.541 metabolites were totally identified,and 45 kinds of metabolites(carbohydrates,fatty acids,flavonoids and terpenoids,etc.)were different between the two strains.The results indicate L-sorbose,D-(+)-glucose,citric acid,L-phenylalanine and oleamide,α-eleostearic acid were the main primary metabolites.The significant difference existed in pathways of unsaturated fatty acids between the studied two strains by pathway enrichment analysis.The results demonstrate that the different in composition,as well as the abundance of primary and secondary metabolites may be the potential causes of taste differences,which provides a new insight into the possible metabolic factors setting off the changing taste of B.ramiflora.

Effect of water deficiency on relationships between metabolism,physiology,biomass,and yield of upland cotton(Gossypium hirsutum L.)

Drought is a common abiotic stress that considerably limits crop production. The objective of this study is to explore the influence of water deficiency on the yield, physiologic and metabolomic attributes in upland cotton cultivars（Gossypium hirsutum L）. Cotton cultivars, ＇Ishonch＇ and ＇Tashkent-6＇ were selected to study the relationships among their physiologic, metabolomic and yield attributes during water deficiency. Deficit irrigation was designed by modifying the traditional watering protocol to reduce water use. Results indicate that cotton cultivars respond differently to water deficit stress. Water deficit significantly influenced plant height, the number of internodes, and sympodial branches in both cultivars. However, yield components such as the number of bolls, boll seed, lint mass, and individual plant yield were significantly reduced only in ＇Tashkent-6＇. The leaf area decreased and the specific leaf weight increased in ＇Ishonch＇ under deficit irrigation conditions. However, ＇Tashkent-6＇ demonstrated significant water loss compared to ＇Ishonch＇, and both cultivars showed reduced transpiration rates. Untargeted metabolite profiles of leaves showed clear separation in ＇Ishonch＇, but not in ＇Tashkent-6＇ under deficit irrigation compared to full irrigation. The individual metabolites such as proline and galactinol showed strong association with yield under water deficit stress. Moreover, this study indicates that leaf area and transpiration intensity influence yield during water deficiency. In summary, the correlation among morpho-physiologic, metabolic, and yield components significantly varied between the two cultivars under water deficiency. The flowering stage was sensitive to water stress for both cultivars. The direct relationship between physiology, metabolism, and yield may be a useful selection criterion for determining candidate parents for cotton drought tolerance breeding.

Solid phase microextraction chemical biopsy tool for monitoring of doxorubicin residue during in vivo lung chemo-perfusion

Development of a novel in vivo lung perfusion(IVLP)procedure allows localized delivery of high-dose doxorubicin(DOX)for targeting residual micrometastatic disease in the lungs.However,DOX delivery via IVLP requires careful monitoring of drug level to ensure tissue concentrations of this agent remain in the therapeutic window.A small dimension nitinol wire coated with a sorbent of biocompatible morphology(Bio-SPME)has been clinically evaluated for in vivo lung tissue extraction and determination of DOX and its key metabolites.The in vivo Bio-SPME-IVLP experiments were performed on pig model over various(150 and 225 mg/m^(2))drug doses,and during human clinical trial.Two patients with metastatic osteosarcoma were treated with a single 5 and 7 μg/mL(respectively)dose of DOX during a 3-h IVLP.In both pig and human cases,DOX tissue levels presented similar trends during IVLP.Human lung tissue concentrations of drug ranged between 15 and 293 μg/g over the course of the IVLP procedure.In addition to DOX levels,Bio-SPME followed by liquid chromatography-mass spectrometry analysis generated 64 metabolic features during endogenous metabolite screening,providing information about lung status during drug administration.Real-time monitoring of DOX levels in the lungs can be performed effectively throughout the IVLP procedure by in vivo Bio-SPME chemical biopsy approach.Bio-SPME also extracted various endogenous molecules,thus providing a real-time snapshot of the physiology of the cells,which might assist in the tailoring of personalized treatment strategy.

Phytochemical investigation, antioxidant and wound healing activities of Citrullus colocynthis (bitter apple)

Objective: To undertake metabolite profiling of various plant parts of Citrullus colocynthis, and assess antioxidant and wound healing activities of fractions for therapeutical applications. Methods: Extracts from leaves, stem, root, fruit pulp and seeds were analyzed using gas chromatography-mass spectrometry and high performance liquid chromatography. Variation in antioxidant potential was assayed by 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging assay. The extract with highest antioxidant potential was subjected on in-vivo wound healing activity using excision wound model. Results: Metabolite profiling of Citrullus colocynthis identified 70 chemically diverse metabolites from different plant parts by using a combination of GC-MS and HPLC. Concentration of colocynthin, a principal active secondary metabolite, ranged from 3.15 mg/g dry weight to 242.00 mg/g dry weight, the lowest being in leaves and highest in fruit pulp. DPPH radical scavenging activity of free radical(IC50) ranged from 196.44 μg/mL in fruit pulp to 413.33 μg/mL in leaves tissues. Significant wound contraction and increase in hydroxyproline content of granulation tissue were observed with ointment formulated from methanolic extract of fruit pulp. Conclusions: The study indicates that the methanol extract of Citrullus colocynthis fruit pulp when applied topically may promote wound contraction in rat model attributable to the accumulation of colocynthin. The high quantity of colocynthin(242.00 mg/g dry weight) and substantial concentration of 2,4-di-tert butyl phenol(3.2%), squalene(4.2%) and δ-tocopherol(2.5%) make this plant to provide new opportunities for development of medicinal, nutraceutical and dietary supplements with optimized functionality.

Metabolic Response of Pakchoi Leaves to Amino Acid Nitrogen

Different nitrogen （N） forms may cause changes in the metabolic profiles of plants. However, few studies have been conducted on the effects of amino acid-N on plant metabolic profiles. The main objective of this study was to identify primary metabolites associated with amino acid-N （Gly, Gln and Ala） through metabolic profile analysis using gas chromatography- mass spectrometry （GC-MS）. Plants of pakchoi （Brassica campestris L. ssp. chinensis L.）, Huawang and Wuyueman cultivars, were grown with different nitrogen forms （i.e., Gly, Gln, Ala, NO3-N, and N starvation） applied under sterile hydroponic conditions. The fresh weight and plant N accumulation of Huawang were greater than those of Wuyueman, which indicates that the former exhibited better N-use efficiency than the latter. The physiological performances of the applied N forms were generally in the order of NO3-N〉Gln〉Gly〉Ala. The metabolic analysis of leaf polar extracts revealed 30 amino acid N-responsive metabolites in the two pakchoi cultivars, mainly consisting of sugars, amino acids, and organic acids. Changes in the carbon metabolism of pakchoi leaves under amino acid treatments occurred via the accumulation of fructose, glucose, xylose, and arabinose. Disruption of amino acid metabolism resulted in accumulation of endogenous Gly in Gly treatment, Pro in Ala treatment, and Asn in three amino acid （Gly, Gln and Ala） treatments. By contrast, the levels of endogenous Gln and Leu decreased. However, this reduction varied among cultivars and amino acid types. Amino acid-N supply also affected the citric acid cycle, namely, the second stage of respiration, where leaves in Gly, Gln and Ala treatments contained low levels of malic, citric and succinic acids compared with leaves in NO3-N treatments. No significant difference in the metabolic responses was observed between the two cultivars which differed in their capability to use N. The response of primary metabolites in pakchoi leaves to amino acid-N supply may serve an important function in pakchoi adaptation to amino acid-N sources.

Salt stress-induced changes in soil metabolites promote cadmium transport into wheat tissues

Soil salinity is known to improve cadmium(Cd)mobility,especially in arid soils.However,the mechanisms involved in how salt stress-associated metabolic profiles participate in mediating Cd transport in the soil-plant system remain poorly understood.This study was designed to investigate the effects of salinity-induced changes in soil metabolites on Cd bioavailability.Sodium salts in different combinations according to molar ratio(NaCl:Na_(2)SO_(4)=1:1;NaCl:Na_(2)SO_(4):NaHCO_(3)=1:2:1;NaCl:Na_(2)SO_(4):NaHCO_(3):Na_(2)CO_(3)=1:9:9:1;NaCl:Na_(2)SO_(4):NaHCO_(3):Na_(2)CO_(3)=1:1:1:1)were applied to the Cd-contaminated soils,which increased soil Cd availability by 22.36%and the Cd content in wheat grains by 36.61%,compared to the control.Salt stress resulted in soil metabolic reprogramming,which might explain the decreased growth of wheat plants and increased Cd transport from the soil into wheat tissues.For example,down-regulation of starch and sucrose metabolism reduced the production of sugars,which adversely affected growth;up-regulation of fatty acid metabolism allowed wheat plants to maintain a normal intracellular environment under saline conditions;up-regulation of the tricarboxylic acid(TCA)cycle was triggered,causing an increase in organic acid synthesis and the accumulation of organic acids,which facilitated the migration of soil Cd into wheat tissues.In summary,salt stress can facilitate Cd transport into wheat tissues by the direct effect of salt-based ions and the combined effect of altered soil physicochemical properties and soil metabolic profiles in Cd-contaminated soils.

Metabolomic Screening Applied to Rice FOX Arabidopsis Lines Leads to the Identification of a Gene-Changing Nitrogen Metabolism

Plant metabolomics developed as a powerful tool to examine gene functions and to gain deeper insight into the physiology of the plant cell. In this study, we screened Arabidopsis lines overexpressing rice full-length （FL） cDNAs （rice FOX Arabidopsis lines） using a gas chromatography-time-of-flight mass spectrometry （GC-TOF/MS）-based technique to identify rice genes that caused metabolic changes. This screening system allows fast and reliable identification of candi- date lines showing altered metabolite profiles. We performed metabolomic and transcriptomic analysis of a rice FOX Ara- bidopsis line that harbored the FL cDNA of the rice ortholog of the Lateral Organ Boundaries （LOB） Domain （LBD）/ Asymmetric Leaves2-1ike （ASL） gene of Arabidopsis, At-LBD37/ASL39. The investigated rice FOX Arabidopsis line showed prominent changes in the levels of metabolites related to nitrogen metabolism. The transcriptomic data as well as the results from the metabolite analysis of the Arabidopsis At-LBD37/ASL39-overexpressor plants were consistent with these findings. Furthermore, the metabolomic and transcriptomic analysis of the Os-LBD37/ASL39-overexpressing rice plants indicated that Os-LBD37/ASL39 is associated with processes related to nitrogen metabolism in rice. Thus, the combination of a metabolomics-based screening method and a gain-of-function approach is useful for rapid characterization of novel genes in both Arabidopsis and rice.

Front line defenders of the ecological niche!Screening the structural diversity of peptaibiotics from saprotrophic and fungicolous Trichoderma/Hypocrea species

Approximately 950 individual sequences of nonribosomally biosynthesised peptides are produced by the genus Trichoderma/Hypocreathat belong to a perpetually growing class of mostly linear antibiotic oligopeptides,which are rich in the non-proteinogenic α-aminoisobutyric acid(Aib).Thus,they are comprehensively named peptaibiotics.Notably,peptaibiotics represent ca.80% of the total inventory of secondarymetabolites currently known from Trichoderma/Hypocrea.Their unique membrane-modifying bioactivity results from amphipathicity and helicity,thus making them ideal candidates in assisting both colonisation and defence of the natural habitats by their fungal producers.Despite this,reports on the in vivo-detection of peptaibiotics have scarcely been published in the past.In order to evaluate the significance of peptaibiotic production for a broader range of potential producers,we screened nine specimens belonging to seven hitherto uninvestigated fungicolous or saprotrophic Trichoderma/Hypocrea species by liquid chromatography coupled to electrospray high resolution mass spectrometry.Sequences of peptaibiotics found were independently confirmed by analysing the peptaibiome of pure agar cultures obtained by single-ascospore isolation from the specimens.Of the nine species examined,five were screened positive for peptaibiotics.A total of 78 peptaibiotics were sequenced,56(=72%)of which are new.Notably,dihydroxyphenylalaninol and O-prenylated tyrosinol,two C-terminal residues,which have not been reported for peptaibiotics before,were found as well as new and recurrent sequences carrying the recently described tyrosinol residue at their C-terminus.The majority of peptaibiotics sequenced are 18-or 19-residue peptaibols.Structural homologies with‘classical representatives’of subfamily 1(SF1)-peptaibiotics argue for the formation of transmembrane ion channels,which are prone to facilitate the producer capture and defence of its substratum.

Recent trends in rapid dereplication of natural product extracts:an update

Natural products are the prominent sources of drugs to combat various infectious diseases.The rapid progress of multi-resistance and pan-resistant pathogens to various medicines represents today a major challenge.The search for novel natural products requires a quick and efficient approach to distinguish novel compounds from the known ones,a process called dereplication.Dereplication strategy is generic and time-saving,avoids isolation/purification of known compounds,enables an efficient liquid chromatography peak annotation of most of the studied compounds and can be well adapted for plant chemotaxonomy,phytochemical screening and metabolite profiling.In this review,recent developments of hyphenated techniques towards dereplication of active compounds,chemotaxonomy,metabolite profiling and rapid detection of novel compounds in medicinal plant extracts are presented.

The utility of metabolomics as a tool to inform maize biology

With the rise of high-throughput omics tools and the importance of maize and its products as food and bioethanol,maize metabolism has been extensively explored.Modern maize is still rich in genetic and phenotypic variation,yielding a wide range of structurally and functionally diversemetabolites.The maize metabolome is also incredibly dynamic in terms of topology and subcellular compartmentalization.In this review,we examine a broad range of studies that cover recent developments in maize metabolism.Particular attention is given to current methodologies and to the use of metabolomics as a tool to define biosynthetic pathways and address biological questions.We also touch upon the use of metabolomics to understand maize natural variation and evolution,with a special focus on research that has used metabolite-based genome-wide association studies(mGWASs).