Structured plant metabolomics for the simultaneous exploration of multiple factors

Metabolomics analysis of rice fermented by medicinal fungi providing insights into the preparation of functional food

Rice, a primary staple food, may be improved in value via fermentation. Here, ten medicinal basidiomycetous fungi were separately applied for rice fermentation. After preliminary screening, Ganoderma boninense, Phylloporia pulla, Sanghuangporus sanghuang and Sanghuangporus weigelae were selected for further LC-MS based determination of the changes in metabolic profile after their fermentation with rice, and a total of 261, 296, 312, and 355 differential compounds were identified, respectively. Most of these compounds were up-regulated and involved in the metabolic pathways of amino acid metabolism, lipid metabolism, carbohydrate metabolism and the biosynthesis of other secondary metabolites. Sanghuangporus weigelae endowed the rice with the highest nutritional and bioactive values. The metabolic network of the identified differential compounds in rice fermented by S. weigelae illustrated their close relationships. In summary, this study provides insights into the preparation and application of potential functional food via the fermentation of rice with medicinal fungi.

Identification and Characterization of Hibiscus mutabilis Varieties Resistant to Bemisia tabaci and Their Resistance Mechanisms

Hibiscus mutabilis, the city flower of Chengdu, is culturally significant and has nutritional and medicinal benefits. However, frequent infestations of Bemisia tabaci have caused economic losses. This study aimed to identify insect-resistant H. mutabilis varieties. Over two years, varieties like Jinqiusong, Zuiyun, and Zuifurong showed moderate to high resistance based on reproductive indices. Assessments of antixenosis and developmental impacts revealed that adult B. tabaci exhibited low selectivity toward these resistant varieties, indicating a strong repellent effect. Gas chromatography-mass spectrometry analysis identified volatile organic compounds, such as alcohols, alkanes, and terpenes. Notably, 2-ethylhexanol and 6-methylheptanol exhibited repellent properties. Using nontargeted metabolomics, this study compared the metabolite profiles of the insect-resistant variety Jinqiusong (JQS), moderately resistant Bairihuacai (BRHC), and highly susceptible Chongbanbai (CBB) post B. tabaci infestation. Fifteen key metabolites were linked to resistance, emphasizing the phenylpropanoid biosynthesis pathway as crucial in defense. These findings offer a theoretical foundation for breeding insect-resistant H. mutabilis varieties and developing eco-friendly strategies against B. tabaci infestations.

The Combination of Buchloe dactyloides Engelm and Biochar Promotes the Remediation of Soil Contaminated with Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) cause serious stress to biological health and the soil environment as persistent pollutants. Despite the wide use of biochar in promoting soil improvement, the mechanism of biochar removing soil PAHs through rhizosphere effect in the process of phytoremediation remain uncertain. In this study, the regulation of soil niche and microbial degradation strategies under plants and biochar were explored by analyzing the effects of plants and biochar on microbial community composition, soil metabolism and enzyme activity in the process of PAH degradation. The combination of plants and biochar significantly increased the removal of phenanthrene (6.10%), pyrene (11.50%), benzo[a]pyrene (106.02%) and PAHs (27.10%) when compared with natural attenuation, and significantly increased the removal of benzo[a]pyrene (34.51%) and PAHs (5.96%) when compared with phytoremediation. Compared with phytoremediation, the combination of plants and biochar significantly increased soil nutrient availability, enhanced soil enzyme activity (urease and catalase), improved soil microbial carbon metabolism and amino acid metabolism, thereby benefiting microbial resistance to PAH stress. In addition, the activity of soil enzymes (dehydrogenase, polyphenol oxidase and laccase) and the expression of genes involved in the degradation and microorganisms (streptomyces, curvularia, mortierella and acremonium) were up-regulated through the combined action of plants and biochar. In view of the aforementioned results, the combined application of plants and biochar can enhance the degradation of PAHs and alleviate the stress of PAH on soil microorganisms.

Synthetic Microbial Community Members Interact to Metabolize Caproic Acid to Inhibit Potato Dry Rot Disease

The potato dry rot disease caused by Fusarium spp. seriously reduces potato yield and threatens human health. However, potential biocontrol agents cannot guarantee the stability and activity of biocontrol. Here, 18 synthetic microbial communities of different scales were constructed, and the synthetic microbial communities with the best biocontrol effect on potato dry rot disease were screened through in vitro and in vivo experiments. The results show that the synthetic community composed of Paenibacillus amylolyticus, Pseudomonas putida, Acinetobacter calcoaceticus, Serratia proteamaculans, Actinomycetia bacterium and Bacillus subtilis has the best biocontrol activity. Metabolomics results show that Serratia protoamaculans interacts with other member strains to produce caproic acid and reduce the disease index to 38.01%. Furthermore, the mycelial growth inhibition after treatment with caproic acid was 77.54%, and flow cytometry analysis showed that the living conidia rate after treatment with caproic acid was 11.2%. This study provides potential value for the application of synthetic microbial communities in potatoes, as well as the interaction mechanisms between member strains of synthetic microbial communities.

Inhibitory effect of benzocaine from Schisandra chinensis on Alternaria alternata

The clinical effects of Schisandra chinensis against human disease are well-documented; however, studies on its application in controlling plant pathogens are limited. Here, we investigated its inhibitory effect on the growth of Alternaria alternata, a fungus which causes significant post-harvest losses on apples, known as black spot disease. S. chinensis fruit extract exhibited strong inhibitory effects on the growth of A. alternata with an EC50 of 1882.00 mg/L. There were 157 compounds identified in the extract by high performance liquid chromatography-mass spectrometry, where benzocaine constituted 14.19% of the extract. Antifungal experiments showed that the inhibitory activity of benzocaine on A. alternata was 43.77-fold higher than the crude extract. The application of benzocaine before and after A. alternata inoculation on apples prevented the pathogen infection and led to mycelial distortion according to scanning electron microscopy. Transcriptome analysis revealed that there were 4226 genes differentially expressed between treated and untreated A. alternata-infected apples with benzocaine. Metabolomics analysis led to the identification of 155 metabolites. Correlation analysis between the transcriptome and metabolome revealed that benzocaine may inhibit A. alternata growth via the beta-alanine metabolic pathway. Overall, S. chinensis extract and benzocaine are environmentally friendly plant-based fungicides with potential to control A. alternata.

Quality evaluation of four Ferula plants and identification of their key volatiles based on non-targeted metabolomics

Introduction

Ferula is a traditional, edible, and important medicinal plant with high economic value. The distinction between edible and non-edible Ferula remains unclear.

Methods

In this study, headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME/GC-MS) and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) non-targeted metabolomics techniques were used to systematically and comprehensively analyse secondary metabolites in the leaves and roots of four species of Ferula, considering their edibility.

Results

A total of 166 leaf volatile organic compounds (VOCs) and 1,079 root metabolites were identified. Additionally, 42 potential VOCs and 62 differential root metabolites were screened to distinguish between edible and non-edible Ferula. Twelve volatile metabolites were specific to F. feurlaeoides, and eight compounds were specific to the three edible Ferula species. The results showed that compounds containing sulphur, aldehydes, and ketones, which produce pungent odours, were the primary sources of the strong odour of Ferula. The root differential metabolites include 13 categories, among which the high concentration group is organic acids, amino acids, terpenoids and fatty acids. The bioactive metabolites and VOCs in the roots exhibited species-specific characteristics. VOCs with various odors were linked to the distribution of root metabolites in both edible and non-edible Ferula plants. The screened root markers may contribute to the formation of characteristic VOCs.

Discussion

This study identified the difference in flavour between edible and non-edible Ferula plants and, for the first time, demonstrated the contribution of the efficacy of Ferula root to the unique flavour of the above-ground parts of Ferula. These results provide a theoretical basis for selecting Ferula for consumption and help evaluate the quality of different species of Ferula. Our findings may facilitate food processing and the further development of Ferula.

Integrative analysis of transcriptome and metabolome reveals the sesquiterpenoids and polyacetylenes biosynthesis regulation in Atractylodes lancea (Thunb.) DC

Atractylodes lancea (Thunb.) is a perennial medicinal herb, with its dry rhizomes are rich in various sesquiterpenoids and polyacetylenes components (including atractylodin, atractylon and β-eudesmol). However, the contents of these compounds are various and germplasms specific, and the mechanisms of biosynthesis in A. lancea are still unknown. In this study, we identified the differentially expressed candidate genes and metabolites involved in the biosynthesis of sesquiterpenoids and polyacetylenes, and speculated the anabolic pathways of these pharmaceutical components by transcriptome and metabolomic analysis. In the sesquiterpenoids biosynthesis, a total of 28 differentially expressed genes (DEGs) and 6 differentially expressed metabolites (DEMs) were identified. The beta-Selinene is likely to play a role in the synthesis of atractylon and β-eudesmol. Additionally, the polyacetylenes biosynthesis showed the presence of 3 DEGs and 4 DEMs. Notably, some fatty acid desaturase (FAB2 and FAD2) significantly down-regulated in polyacetylenes biosynthesis. The gamma-Linolenic acid is likely involved in the biosynthesis of polyacetylenes and thus further synthesis of atractylodin. Overall, these studies have investigated the biosynthetic pathways of atractylodin, atractylon and β-eudesmol in A. lancea for the first time, and present potential new anchor points for further exploration of sesquiterpenoids and polyacetylenes compound biosynthesis pathways in A. lancea.

Unraveling symbiotic microbial communities, metabolomics and volatilomics profiles of kombucha from diverse regions in China

Kombucha is a natural fermented beverage (mixed system). This study aimed to unravel the signatures of kombucha in China to achieve tailor-made microbial consortium. Here, biochemical parameters, microbiome, metabolite production and volatile profile were comprehensively compared and characterized across four regions (AH, HN, SD, SX), both commonalities and distinctions were highlighted. The findings revealed that yeast species yeast Starmerella, Zygosaccharomyces, Dekkera, Pichia and bacterium Komagataeibacter, Gluconobacter were the most common microbes. Additionally, the composition, distribution and stability of microbial composition in liquid phase were superior to those in biofilm. The species diversity, differences, marker and association were analyzed across four areas. Metabolite profiles revealed a total of 163 bioactive compounds (23 flavonoids, 13 phenols), and 68 differential metabolites were screened and identified. Moreover, the metabolic pathways of phenylpropanoids biosynthesis were closely linked with the highest number of metabolites, followed by flavonoid biosynthesis. Sixty-five volatile compounds (23 esters) were identified. Finally, the correlation analysis among the microbial composition and volatile and functional metabolites showed that Komagataeibacter, Gluconolactone, Zygosacchaaromycess, Starmerella and Dekkera seemed closely related to bioactive compounds, especially Komagataeibacter displayed positive correlations with 1-hexadecanol, 5-keto-D-gluconate, L-malic acid, 6-aminohexanoate, Starmerella contributed greatly to gluconolactone, thymidine, anabasine, 2-isopropylmalic acid. Additionally, Candida was related to β-damascenone and α-terpineol, and Arachnomyces and Butyricicoccus showed the consistency of associations with specific esters and alcohols. These findings provided crucial information for creating a stable synthetic microbial community structure, shedding light on fostering stable kombucha and related functional beverages.

Metabolomic and transcriptomic analysis of cold plasma promoting biosynthesis of active substances in broccoli sprouts

INTRODUCTION

Broccoli sprouts have great health and commercial value because they are rich in sulforaphane, a special bioactive compound that helps to prevent chronic diseases, such as cancer and cardiovascular disease.

OBJECTIVE

The aim of this study was to increase the levels of active substances in broccoli sprouts and understand their metabolic mechanisms.

METHODOLOGY

Metabolomics based on liquid chromatography-tandem mass spectrometry and transcriptome analysis were combined to analyse the enrichment of metabolites in broccoli sprouts treated with cold plasma.

RESULTS

After 2 min of cold plasma treatment, the contents of sulforaphane, glucosinolates, total phenols, and flavonoids, as well as myrosinase activity, were greatly improved. Transcriptomics revealed 7460 differentially expressed genes in the untreated and treated sprouts. Metabolomics detected 6739 differential metabolites, including most amino acids, their derivatives, and organic acids. Enrichment analyses of metabolomics and transcriptomics identified the 20 most significantly differentially expressed metabolic pathways.

CONCLUSIONS

Overall, cold plasma treatment can induce changes in the expression and regulation of certain metabolites and genes encoding active substances in broccoli sprouts.

The toxicological effect on pak choi of co-exposure to degradable and non-degradable microplastics with oxytetracycline in the soil

Microplastics and antibiotics are emerging as ubiquitous contaminants in farmland soil, harming crop quality and yield, and thus threatening global food security and human health. However, few studies have examined the individual and joint effects of degradable and/or non-degradable microplastics and antibiotics on crop plants. This study examined the individual and joint effects of polyethylene (PE) and polylactic acid (PLA) microplastics and the antibiotic oxytetracycline (OTC) on pak choi by measuring its growth, photosynthesis, antioxidant enzyme activity, and metabolite levels. Microplastics and/or oxytetracycline adversely affected root weight, photosynthesis, and antioxidant enzyme (superoxide dismutase, catalase, and ascorbate peroxidase) activities. The levels of leaf metabolites were significantly altered, causing physiological changes. Biosynthesis of plant secondary metabolites and amino acids was altered, and plant hormones pathways were disrupted. Separately and together, OTC, PE, and PLA exerted phytotoxic and antagonistic effects on pak choi. Separately and together with OTC, degradable microplastics altered the soil properties, thus causing more severe impacts on plant performance than non-degradable microplastics. This study elucidates the effects on crop plants of toxicity caused by co-exposure to degradable or non-degradable microplastic and antibiotics contamination and suggests mechanisms.

Morphological, physiological and metabolomic analysis to unravel the adaptive relationship between root growth of ephemeral plants and different soil habitats

To gain insights into the adaptive characteristics of ephemeral plants and enrich their potential for resource exploitation, the adaptive changes in two highly dominant species (Malcolmia scorpioides and Isatis violascens) to soil habitats (aeolian soil, AS; grey desert soil, GS) were investigated from the aspects of root morphology, physiology, and metabolism in this study. The results revealed that changes in root morphology and enzyme activity were affected by soil habitat. Total root length (TRL), root volume (RV) and root surface area (RSA) were higher in GS than in AS. The levels of proline (Pro), glutathione (GSH), soluble sugar (SS), and lysine (Lys) were higher in GS than in AS. Untargeted LC-MS metabolomics indicates that root metabolites of both species differed among the two soil habitats. Root responses to different soil habitats mainly affected some metabolic pathways. A total of 780 metabolites were identified, common differential metabolites (DMs) in both species included amino acids, fatty acids, organic acids, carbohydrates, benzene and derivatives, and flavonoids, which were mainly involved in carbohydrate metabolism, amino acid metabolism, flavonoid biosynthesis and fatty acid metabolism, and their abundance varied among different habitats and species. Some key DMs were significantly related to root morphology and enzyme activity, and indole, malonate, quercetin, uridine, tetrahydroharmine, and gluconolactone were important metabolites associated with root growth. Therefore, the response changes in root growth and metabolite of ephemeral plants in response to soil habitats reflect their ecological adaptation, and lay a foundation for the exploitation of plant resources in various habitats.

Study on morphological traits, nutrient compositions and comparative metabolomics of diploid and tetraploid Tartary buckwheat sprouts during sprouting

Tartary buckwheat (TB) sprout is a kind of novel nutritional vegetable, but its consumption was limited by low biomass and thin hypocotyl. The tetraploid TB sprouts was considered to be able to solve this issue. However, the nutritional quality of tetraploid TB sprouts and differences between conventional (diploid) and tetraploid TB sprouts remain unclear. In this study, the morphological traits, nutrient compositions and metabolome changes of diploid and tetraploid TB sprouts were analyzed. The water, pigments and minerals contents of TB sprouts increased during sprouting, while the contents of total soluble protein, reducing sugar, cellulose, and total phenol decreased. Compared with diploid sprouts, tetraploid sprouts had higher biomass and thicker hypocotyl. Tetraploid sprouts had higher ash and carotenoid contents, but had lower phenol and flavonoid accumulation. 677 metabolites were identified in TB sprouts by UPLC-MS analysis, including 62 diseases-resistance metabolites and 43 key active ingredients. Some key bioactive metabolites, such as rimonabant, quinapril, 1-deoxynojirimycin and miglitol, were identified. 562 differential expressed metabolites (DEMs) were identified during sprouting with seven accumulation patterns, and five hormones were found to be involved in sprout development. Additionally, 209 DEMs between diploid and tetraploid sprouts were found, and some key bioactive metabolites were induced by chromosome doubling such as mesoridazine, amaralin, atractyloside A, rhamnetin and Qing Hau Sau. This work lays a basis for the development and utilization of TB sprouts and provides evidence for the selection of tetraploid varieties to produce sprouts with high biomass and quality.

Combined metabolomic and transcriptomic analysis reveals key components of OsCIPK17 overexpression improves drought tolerance in rice

Oryza Sativa is one of the most important food crops in China, which is easily affected by drought during its growth and development. As a member of the calcium signaling pathway, CBL-interacting protein kinase (CIPK) plays an important role in plant growth and development as well as environmental stress. However, there is no report on the function and mechanism of OsCIPK17 in rice drought resistance. We combined transcriptional and metabonomic analysis to clarify the specific mechanism of OsCIPK17 in response to rice drought tolerance. The results showed that OsCIPK17 improved drought resistance of rice by regulating deep roots under drought stress; Response to drought by regulating the energy metabolism pathway and controlling the accumulation of citric acid in the tricarboxylic acid (TCA) cycle; Our exogenous experiments also proved that OsCIPK17 responds to citric acid, and this process involves the auxin metabolism pathway; Exogenous citric acid can improve the drought resistance of overexpression plants. Our research reveals that OsCIPK17 positively regulates rice drought resistance and participates in the accumulation of citric acid in the TCA cycle, providing new insights for rice drought resistance.

Phytotoxic Metabolites Produced by Fungi Involved in Grapevine Trunk Diseases: Progress, Challenges, and Opportunities

Grapevine trunk diseases (GTDs), caused by fungal pathogens, are a serious threat to vineyards worldwide, causing significant yield and economic loss. To date, curative methods are not available for GTDs, and the relationship between the pathogen and symptom expression is poorly understood. Several plant pathologists, molecular biologists, and chemists have been investigating different aspects of the pathogenicity, biochemistry, and chemical ecology of the fungal species involved in GTDs. Many studies have been conducted to investigate virulence factors, including the chemical characterization of phytotoxic metabolites (PMs) that assist fungi in invading and colonizing crops such as grapevines. Moreover, multidisciplinary studies on their role in pathogenicity, symptom development, and plant-pathogen interactions have also been carried out. The aim of the present review is to provide an illustrative overview of the biological and chemical characterization of PMs produced by fungi involved in Eutypa dieback, Esca complex, and Botryosphaeria dieback. Moreover, multidisciplinary investigations on host-pathogen interactions, including those using cutting-edge Omics techniques, will also be reviewed and discussed. Finally, challenges and opportunities in the role of PMs for reliable field diagnosis and control of GTDs in vineyards will also be explored.

Combined Metabolomic and Transcriptomic Analysis Reveals Allantoin Enhances Drought Tolerance in Rice

Drought is a misfortune for agriculture and human beings. The annual crop yield reduction caused by drought exceeds the sum of all pathogens. As one of the gatekeepers of China's "granary", rice is the most important to reveal the key drought tolerance factors in rice. Rice seedlings of Nipponbare (Oryza sativa L. ssp. Japonica) were subjected to simulated drought stress, and their root systems were analyzed for the non-targeted metabolome and strand-specific transcriptome. We found that both DEGs and metabolites were enriched in purine metabolism, and allantoin accumulated significantly in roots under drought stress. However, few studies on drought tolerance of exogenous allantoin in rice have been reported. We aimed to further determine whether allantoin can improve the drought tolerance of rice. Under the treatment of exogenous allantoin at different concentrations, the drought resistant metabolites of plants accumulated significantly, including proline and soluble sugar, and reactive oxygen species (ROS) decreased and reached a significant level in 100 μmol L^-1. To this end, a follow-up study was identified in 100 μmol L^-1 exogenous allantoin and found that exogenous allantoin improved the drought resistance of rice. At the gene level, under allantoin drought treatment, we found that genes of scavenge reactive oxygen species were significantly expressed, including peroxidase (POD), catalase (CATA), ascorbate peroxidase 8 (APX8) and respiratory burst oxidase homolog protein F (RbohF). This indicates that plants treated by allantoin have better ability to scavenge reactive oxygen species to resist drought. Alternative splicing analysis revealed a total of 427 differentially expressed alternative splicing events across 320 genes. The analysis of splicing factors showed that gene alternative splicing could be divided into many different subgroups and play a regulatory role in many aspects. Through further analysis, we restated the key genes and enzymes in the allantoin synthesis and catabolism pathway, and found that the expression of synthetase and hydrolase showed a downward trend. The pathway of uric acid to allantoin is completed by uric acid oxidase (UOX). To find out the key transcription factors that regulate the expression of this gene, we identified two highly related transcription factors OsERF059 and ONAC007 through correlation analysis. They may be the key for allantoin to enhance the drought resistance of rice.

Medicinal Plants: Guests and Hosts in the Heterologous Expression of High-Value Products

Medicinal plants play an important dual role in the context of the heterologous expression of high-value pharmaceutical products. On the one hand, the classical biochemical and modern omics approaches allowed for the discovery of various genes encoding biosynthetic pathways in medicinal plants. Recombinant DNA technology enabled introducing these genes and regulatory elements into host organisms and enhancing the heterologous production of the corresponding secondary metabolites. On the other hand, the transient expression of foreign DNA in plants facilitated the production of numerous proteins of pharmaceutical importance. This review summarizes several success stories of the engineering of plant metabolic pathways in heterologous hosts. Likewise, a few examples of recombinant protein expression in plants for therapeutic purposes are also highlighted. Therefore, the importance of medicinal plants has grown immensely as sources for valuable products of low and high molecular weight. The next step ahead for bioengineering is to achieve more success stories of industrial-scale production of secondary plant metabolites in microbial systems and to fully exploit plant cell factories' commercial potential for recombinant proteins.

Untargeted and Targeted LC-MS/MS Based Metabolomics Study on In Vitro Culture of Phaeoacremonium Species

Grapevine (Vitis vinifera L.) can be affected by many different biotic agents, including tracheomycotic fungi such as Phaeomoniella chlamydospora and Phaeoacremonium minimum, which are the main causal agent of Esca and Petri diseases. Both fungi produce phytotoxic naphthalenone polyketides, namely scytalone and isosclerone, that are related to symptom development. The main objective of this study was to investigate the secondary metabolites produced by three Phaeoacremonium species and to assess their phytotoxicity by in vitro bioassay. To this aim, untargeted and targeted LC-MS/MS-based metabolomics were performed. High resolution mass spectrometer UHPLC-Orbitrap was used for the untargeted profiling and dereplication of secondary metabolites. A sensitive multi reaction monitoring (MRM) method for the absolute quantification of scytalone and isosclerone was developed on a UPLC-QTrap. Different isolates of P. italicum, P. alvesii and P. rubrigenum were grown in vitro and the culture filtrates and organic extracts were assayed for phytotoxicity. The toxic effects varied within and among fungal isolates. Isosclerone and scytalone were dereplicated by matching retention times and HRMS and MS/MS data with pure standards. The amount of scytalone and isosclerone differed within and among fungal species. To our best knowledge, this is the first study that applies an approach of LC-MS/MS-based metabolomics to investigate differences in the metabolic composition of organic extracts of Phaeoacremonium species culture filtrates.

Microwave-Assisted Extraction and HPLC-UV-CD Determination of (S)-usnic Acid in Cladonia foliacea

During the years, many usnic acid (UA) conjugates have been synthesized to obtain potent endowed with biological properties. Since (S)-UA is less abundant in nature than (R)-enantiomer, it is difficult to source, thus precluding a deeper investigation. Among the lichens producing UA, Cladonia foliacea is a valuable (S)-UA source. In the present work, we report on a rapid HPLC-UV/PAD-CD protocol suitable for the analysis and the identification of the main secondary metabolites present in C. foliacea extract. Best results were achieved using XBridge Phenyl column and acetonitrile and water, which were both added with formic acid as mobile phase in gradient elution. By combining analytical, spectroscopical, and chiroptical analysis, the most abundant analyte was unambiguously identified as (S)-UA. Accordingly, a versatile microwave-assisted extractive (MAE) protocol, assisted by a design of experiment (DoE), to quantitatively recover (S)-UA was set up. The best result in terms of UA extraction yield was obtained using ethanol and heating at 80 °C under microwave irradiation for 5 min. Starting from 100 g of dried C. foliacea, 420 mg of (S)-UA were achieved. Thus, our extraction method resulted in a suitable protocol to produce (S)-UA from C. foliacea for biological and pharmaceutical investigation or commercial purposes.

Metabolomics for a Millenniums-Old Crop: Tea Plant ( Camellia sinensis)

Tea cultivation and utilization dates back to antiquity. Today it is the most widely consumed beverage on earth due to its pleasant taste and several beneficial health properties attributed to specific metabolites. Metabolomics has a tremendous potential to correlate tea metabolites with taste and health properties in humans. Our review on the current application of metabolomics in the science of tea suggests that metabolomics is a promising frontier in the evaluation of tea quality, identification of functional genes responsible for key metabolites, investigation of their metabolic regulation, and pathway analysis in the tea plant. Furthermore, the challenges, possible solutions, and the prospects of metabolomics in tea science are reviewed.

Untargeted LC-MS metabolomic studies of Asteraceae species to discover inhibitors of Leishmania major dihydroorotate dehydrogenase

INTRODUCTION

Interesting data about the family Asteraceae as a new source of Leishmania major dihydroorotate dehydrogenase (LmDHODH) inhibitors are presented. This key macromolecular target for parasites causing neglected diseases catalyzes the fourth reaction of the de novo pyrimidine biosynthetic pathway, which takes part in major cell functions, including DNA and RNA biosynthesis.

OBJECTIVES

We aimed to (1) determine LmDHODH inhibitor candidates, revealing the type of chemistry underlying such bioactivity, and (2) predict the inhibitory potential of extracts from new untested plant species, classifying them as active or inactive based on their LC-MS based metabolic fingerprints.

METHODS

Extracts from 150 species were screened for the inhibition of LmDHODH, and untargeted UHPLC-(ESI)-HRMS metabolomic studies were carried out in combination with in silico approaches.

RESULTS

The IC₅₀ values determined for a subset of 59 species ranged from 148 µg mL^-1 to 9.4 mg mL^-1. Dereplication of the metabolic fingerprints allowed the identification of 48 metabolites. A reliable OPLS-DA model (R² > 0.9, Q² > 0.7, RMSE_CV < 0.3) indicated the inhibitor candidates; nine of these metabolites were identified using data from isolated chemical standards, one of which-4,5-di-O-E-caffeoylquinic acid (IC₅₀ 73 µM)-was capable of inhibiting LmDHODH. The predictive OPLS model was also effective, with 60% correct predictions for the test set.

CONCLUSION

Our approach was validated for (1) the discovery of LmDHODH inhibitors or interesting starting points for the optimization of new leishmanicides from Asteraceae species and (2) the prediction of extracts from untested species, classifying them as active or inactive.

Induced, Imprinted, and Primed Responses to Changing Environments: Does Metabolism Store and Process Information?

Metabolism is the system layer that determines growth by the rate of matter uptake and conversion into biomass. The scaffold of enzymatic reaction rates drives the metabolic network in a given physico-chemical environment. In response to the diverse environmental stresses, plants have evolved the capability of integrating macro- and micro-environmental events to be prepared, i.e., to be primed for upcoming environmental challenges. The hierarchical view on stress signaling, where metabolites are seen as final downstream products, has recently been complemented by findings that metabolites themselves function as stress signals. We present a systematic concept of metabolic responses that are induced by environmental stresses and persist in the plant system. Such metabolic imprints may prime metabolic responses of plants for subsequent environmental stresses. We describe response types with examples of biotic and abiotic environmental stresses and suggest that plants use metabolic imprints, the metabolic changes that last beyond recovery from stress events, and priming, the imprints that function to prepare for upcoming stresses, to integrate diverse environmental stress histories. As a consequence, even genetically identical plants should be studied and understood as phenotypically plastic organisms that continuously adjust their metabolic state in response to their individually experienced local environment. To explore the occurrence and to unravel functions of metabolic imprints, we encourage researchers to extend stress studies by including detailed metabolic and stress response monitoring into extended recovery phases.

An Introduction to Plant Tissue Culture: Advances and Perspectives

Plant tissue culture techniques are the most frequently used biotechnological tools for basic and applied purposes ranging from investigation on plant developmental processes, functional gene studies, commercial plant micropropagation, generation of transgenic plants with specific industrial and agronomical traits, plant breeding and crop improvement, virus elimination from infected materials to render high-quality healthy plant material, preservation and conservation of germplasm of vegetative propagated plant crops, and rescue of threatened or endangered plant species. Additionally, plant cell and organ cultures are of interest for the production of secondary metabolites of industrial and pharmaceutical interest. New technologies, such as the genome editing ones combined with tissue culture and Agrobacterium tumefaciens infection, are currently promising alternatives for the highly specific genetic manipulation of interesting agronomical or industrial traits in crop plants. Application of omics (genomics, transcriptomics, and proteomics) to plant tissue culture will certainly help to unravel complex developmental processes such as organogenesis and somatic embryogenesis, which will probably enable to improve the efficiency of regeneration protocols for recalcitrant species. Additionally, metabolomics applied to tissue culture will facilitate the extraction and characterization of complex mixtures of natural plant products of industrial interest. General and specific aspects and applications of plant tissue culture and the advances and perspectives are described in this edition.