Metabolomics to Characterize Adaptive and Signaling Responses in Legume Crops under Abiotic Stresses

Lentil adaptation to drought stress: response, tolerance, and breeding approaches

Lentil (Lens culinaris Medik.) is a cool season legume crop that plays vital roles in food and nutritional security, mostly in the least developed countries. Lentil is often cultivated in dry and semi-dry regions, where the primary abiotic factor is drought, which negatively impacts lentil growth and development, resulting in a reduction of yield. To withstand drought-induced multiple negative effects, lentil plants evolved a variety of adaptation strategies that can be classified within three broad categories of drought tolerance mechanisms (i.e., escape, avoidance, and tolerance). Lentil adapts to drought by the modulation of various traits in the root system, leaf architecture, canopy structure, branching, anatomical features, and flowering process. Furthermore, the activation of certain defensive biochemical pathways as well as the regulation of gene functions contributes to lentil drought tolerance. Plant breeders typically employ conventional and mutational breeding approaches to develop lentil varieties that can withstand drought effects; however, little progress has been made in developing drought-tolerant lentil varieties using genomics-assisted technologies. This review highlights the current understanding of morpho-physiological, biochemical, and molecular mechanisms of lentil adaptation to drought stress. We also discuss the potential application of omics-assisted breeding approaches to develop lentil varieties with superior drought tolerance traits.

Unlocking Hidden Treasures: LC-MS/MS Molecular Networks for Exploring Novel Passiflora Species with Pharmaceutical Potential

In this study, we report the metabolic profiling of several previously uncharacterized Passiflora species native to Brazil, employing molecular networks to delve deeper into chemical constituents. Using the GNPS platform, in silico tools, and substructure annotation techniques, we expanded the chemical annotations. Principal Coordinate Analysis (PCoA) revealed significant metabolic similarities between several species, including P. incarnata, suggesting shared pharmacological potential. Our identification of metabolic compounds facilitated comparisons between understudied species with medicinal properties. Notably, we documented 25 previously uncharacterized species, paving the way for the development of novel products aimed at improving human well-being. This research focused on several native Passiflora species from Brazil, highlighting their unexplored therapeutic potential.

Identification of mungbean yellow mosaic India virus and susceptibility-related metabolites in the apoplast of mung bean leaves

KEY MESSAGE

The investigation of MYMIV-infected mung bean leaf apoplast revealed viral genome presence, increased EVs secretion, and altered stress-related metabolite composition, providing comprehensive insights into plant-virus interactions. The apoplast, an extracellular space around plant cells, plays a vital role in plant-microbe interactions, influencing signaling, defense, and nutrient transport. While the involvement of apoplast and extracellular vesicles (EVs) in RNA virus infection is documented, the role of the apoplast in plant DNA viruses remains unclear. This study explores the apoplast's role in mungbean yellow mosaic India virus (MYMIV) infection. Our findings demonstrate the presence of MYMIV genomic components in apoplastic fluid, suggesting potential begomovirus cell-to-cell movement via the apoplast. Moreover, MYMIV infection induces increased EVs secretion into the apoplast. NMR-based metabolomics reveals altered metabolic profiles in both apoplast and symplast in response to MYMIV infection, highlighting key metabolites associated with stress and defense mechanisms. The data show an elevation of α- and β-glucose in both apoplast and symplast, suggesting a shift in glucose utilization. Interestingly, this increase in glucose does not contribute to the synthesis of phenolic compounds, potentially influencing the susceptibility of mung bean to MYMIV. Fructose levels increase in the symplast, while apoplastic sucrose levels rise significantly. Symplastic aspartate levels increase, while proline exhibits elevated concentration in the apoplast and reduced concentration in the cytosol, suggesting a role in triggering a hypersensitive response. These findings underscore the critical role of the apoplast in begomovirus infection, providing insights for targeted viral disease management strategies.

Effects of geographical origin and post-harvesting processing on the bioactive compounds and sensory quality of Brazilian specialty coffee beans

Specialty coffee beans are those produced, processed, and characterized following the highest quality standards, toward delivering a superior final product. Environmental, climatic, genetic, and processing factors greatly influence the green beans' chemical profile, which reflects on the quality and pricing. The present study focuses on the assessment of eight major health-beneficial bioactive compounds in green coffee beans aiming to underscore the influence of the geographical origin and post-harvesting processing on the quality of the final beverage. For that, we examined the non-volatile chemical profile of specialty Coffea arabica beans from Minas Gerais state, Brazil. It included samples from Cerrado (Savannah), and Matas de Minas and Sul de Minas (Atlantic Forest) regions, produced by two post-harvesting processing practices. Trigonelline, theobromine, theophylline, chlorogenic acid derivatives, caffeine, caffeic acid, ferulic acid, and p-coumaric acid were quantified in the green beans by high-performance liquid chromatography with diode array detection. Additionally, all samples were roasted and subjected to sensory analysis for coffee grading. Principal component analysis suggested that Cerrado samples tended to set apart from the other geographical locations. Those samples also exhibited higher levels of trigonelline as confirmed by two-way ANOVA analysis. Samples subjected to de-pulping processing showed improved chemical composition and sensory score. Those pulped coffees displayed 5.8% more chlorogenic acid derivatives, with an enhancement of 1.5% in the sensory score compared to unprocessed counterparts. Multivariate logistic regression analysis pointed out altitude, ferulic acid, p-coumaric acid, sweetness, and acidity as predictors distinguishing specialty coffee beans obtained by the two post-harvest processing. These findings demonstrate the influence of regional growth conditions and post-harvest treatments on the chemical and sensory quality of coffee. In summary, the present study underscores the value of integrating target metabolite analysis with statistical tools to augment the characterization of specialty coffee beans, offering novel insights for quality assessment with a focus on their bioactive compounds.

NMR Metabolite Profiling for the Characterization of Vessalico Garlic Ecotype and Bioactivity against Xanthomonas campestris pv. campestris

The Italian garlic ecotype "Vessalico" possesses distinct characteristics compared to its French parent cultivars Messidor and Messidrôme, used for sowing, as well as other ecotypes in neighboring regions. However, due to the lack of a standardized seed supply method and cultivation protocol among farmers in the Vessalico area, a need to identify garlic products that align with the Vessalico ecotype arises. In this study, an NMR-based approach followed by multivariate analysis to analyze the chemical composition of Vessalico garlic sourced from 17 different farms, along with its two French parent cultivars, was employed. Self-organizing maps allowed to identify a homogeneous subset of representative samples of the Vessalico ecotype. Through the OPLS-DA model, the most discriminant metabolites based on values of VIP (Variable Influence on Projections) were selected. Among them, S-allylcysteine emerged as a potential marker for distinguishing the Vessalico garlic from the French parent cultivars by NMR screening. Additionally, to promote sustainable agricultural practices, the potential of Vessalico garlic extracts and its main components as agrochemicals against Xanthomonas campestris pv. campestris, responsible for black rot disease, was explored. The crude extract exhibited a MIC of 125 μg/mL, and allicin demonstrated the highest activity among the tested compounds (MIC value of 31.25 μg/mL).

Comparative differences in maintaining membrane fluidity and remodeling cell wall between Glycine soja and Glycine max leaves under drought

Water shortage is one of the most important environmental factors limiting crop yield. In this study, we used wild soybean (Glycine soja Sieb. et Zucc.) and soybean (Glycinemax (L.) Merr.) seedlings as experimental materials, simulated drought stress using soil gravimetry, measured growth and physiological parameters, and analyzed differentially expressed genes and metabolites in the leaves of seedling by integrated transcriptomics and metabolomics techniques. The results indicate that under water deficit, Glycine soja maintained stable photosynthate by accumulating Mg2+, Fe3+, Mn2+, Zn2+ and B3+, and improved water absorption by increasing root growth. Notably, Glycine soja enhanced linoleic acid metabolism and plasma membrane intrinsic protein (PIP1) gene expression to maintain membrane fluidity, and increased pentose, glucuronate and galactose metabolism and thaumatin protein genes expression to remodel the cell wall, thereby increasing water-absorption to better tolerate to drought stress. In addition, it was found that secondary phenolic metabolism, such as phenylpropane biosynthesis, flavonoid biosynthesis and ascobate and aldarate metabolism were weakened, resulting in the collapse of the antioxidant system, which was the main reason for the sensitivity of Glycine max to drought stress. These results provide new insights into plant adaptation to water deficit and offer a theoretical basis for breeding soybean varieties with drought tolerance.

Metabolomics approach to understand molecular mechanisms involved in fungal pathogen-citrus pathosystems

Citrus is a crucial crop with a significant economic impact globally. However, postharvest decay caused by fungal pathogens poses a considerable threat, leading to substantial financial losses. Penicillium digitatum, Penicillium italicum, Geotrichum citri-aurantii and Phyllosticta citricarpa are the main fungal pathogens, causing green mold, blue mold, sour rot and citrus black spot diseases, respectively. The use of chemical fungicides as a control strategy in citrus raises concerns about food and environmental safety. Therefore, understanding the molecular basis of host-pathogen interactions is essential to find safer alternatives. This review highlights the potential of the metabolomics approach in the search for bioactive compounds involved in the pathogen-citrus interaction, and how the integration of metabolomics and genomics contributes to the understanding of secondary metabolites associated with fungal virulence and the fungal infection mechanisms. Our goal is to provide a pipeline combining metabolomics and genomics that can effectively guide researchers to perform studies aiming to contribute to the understanding of the fundamental chemical and biochemical aspects of pathogen-host interactions, in order to effectively develop new alternatives for fungal diseases in citrus cultivation. We intend to inspire the scientific community to question unexplored biological systems, and to employ diverse analytical approaches and metabolomics techniques to address outstanding questions about the non-studied pathosystems from a chemical biology perspective.

Functional insight into multi-omics-based interventions for climatic resilience in sorghum (Sorghum bicolor): a nutritionally rich cereal crop

MAIN CONCLUSION

The article highlights omics-based interventions in sorghum to combat food and nutritional scarcity in the future. Sorghum with its unique ability to thrive in adverse conditions, has become a tremendous highly nutritive, and multipurpose cereal crop. It is resistant to various types of climatic stressors which will pave its way to a future food crop. Multi-omics refers to the comprehensive study of an organism at multiple molecular levels, including genomics, transcriptomics, proteomics, and metabolomics. Genomic studies have provided insights into the genetic diversity of sorghum and led to the development of genetically improved sorghum. Transcriptomics involves analysing the gene expression patterns in sorghum under various conditions. This knowledge is vital for developing crop varieties with enhanced stress tolerance. Proteomics enables the identification and quantification of the proteins present in sorghum. This approach helps in understanding the functional roles of specific proteins in response to stress and provides insights into metabolic pathways that contribute to resilience and grain production. Metabolomics studies the small molecules, or metabolites, produced by sorghum, provides information about the metabolic pathways that are activated or modified in response to environmental stress. This knowledge can be used to engineer sorghum varieties with improved metabolic efficiency, ultimately leading to better crop yields. In this review, we have focused on various multi-omics approaches, gene expression analysis, and different pathways for the improvement of Sorghum. Applying omics approaches to sorghum research allows for a holistic understanding of its genome function. This knowledge is invaluable for addressing challenges such as climate change, resource limitations, and the need for sustainable agriculture.

Metabolome profile variation in Azolla filiculoides exposed to Bisphenol A assists in the identification of stress-responsive metabolites

This study attempted to explore the metabolome profile of Azolla filiculoides subjected to two different concentrations of BPA (1 and 30 mg L-1) in congruence with two different durations (3 and 9 days) of treatment. Bisphenol A (BPA) is a ubiquitously occurring environmental pollutant that imparts acute toxicity in aquatic plants. Therefore, studying the variations in the fern metabolome profile and identifying stress-responsive metabolites can help develop criteria for assessing the aquatic ecosystem. In recent times, metabolomics has drawn attention for its ability to detect biochemical processes and help link plant responses with environmental stresses. However, the studies concerning the metabolome profile of A. filiculoides exposed to environmental contaminants are limited. In the present study, the untargeted metabolomics study allowed the detection of a large array of metabolites, with 767 shared metabolites representing 41 crucial pathways. Exposure to 30 mg L-1 BPA seemingly disrupted the primary metabolism of the fern and induced a shift toward defense-related pathways. Additionally, BPA stress triggered the expression of metabolites like 3,4-dihydroxyphenylglycol, perillic acid, and perillaldehyde in BPA_L3 (1 mg L-1 for 3 days) and BPA_L9 (1 mg L-1 for 9 days) samples indicating protective mechanism of the plants. Conversely, the BPA_H3 (30 mg L-1 for 3 days) and BPA_H9 (30 mg L-1 for 9 days) samples expressed a distinct set of markers like luteolin, 3-hydroxyanthranilic acid, cinnamaldehyde, and l-DOPA indicating the onset of senescence and apoptosis related pathways can help in the health assessment of freshwater ecosystems and also appraisal of ecotoxicological risks imposed by BPA.

Toxic effects of lead on plants: integrating multi-omics with bioinformatics to develop Pb-tolerant crops

MAIN CONCLUSION

Lead disrupts plant metabolic homeostasis and key structural elements. Utilizing modern biotechnology tools, it's feasible to develop Pb-tolerant varieties by discovering biological players regulating plant metabolic pathways under stress. Lead (Pb) has been used for a variety of purposes since antiquity despite its toxic nature. After arsenic, lead is the most hazardous heavy metal without any known beneficial role in the biological system. It is a crucial inorganic pollutant that affects plant biochemical and morpho-physiological attributes. Lead toxicity harms plants throughout their life cycle and the extent of damage depends on the concentration and duration of exposure. Higher levels of lead exposure disrupt numerous key metabolic activities of plants including oxygen-evolving complex, organelles integrity, photosystem II connectivity, and electron transport chain. This review summarizes the detrimental effects of lead toxicity on seed germination, crop growth, and yield, oxidative and ultra-structural alterations, as well as nutrient absorption, transport, and assimilation. Further, it discusses the Pb-induced toxic modulation of stomatal conductance, photosynthesis, respiration, metabolic-enzymatic activity, osmolytes accumulation, and antioxidant activity. It is a comprehensive review that reports on omics-based studies along with morpho-physiological and biochemical modifications caused by lead stress. With advances in DNA sequencing technologies, genomics and transcriptomics are gradually becoming popular for studying Pb stress effects in plants. Proteomics and metabolomics are still underrated and there is a scarcity of published data, and this review highlights both their technical and research gaps. Besides, there is also a discussion on how the integration of omics with bioinformatics and the use of the latest biotechnological tools can aid in developing Pb-tolerant crops. The review concludes with core challenges and research directions that need to be addressed soon.

Metabolic Mechanisms Underlying Heat and Drought Tolerance in Lentil Accessions: Implications for Stress Tolerance Breeding

Climate change has significantly exacerbated the effects of abiotic stresses, particularly high temperatures and drought stresses. This study aims to uncover the mechanisms underlying heat and drought tolerance in lentil accessions. To achieve this objective, twelve accessions were subjected to high-temperature stress (32/20 °C), while seven accessions underwent assessment under drought stress conditions (50% of field capacity) during the reproductive stage. Our findings revealed a significant increase in catalase activity across all accessions under both stress conditions, with ILL7814 and ILL7835 recording the highest accumulations of 10.18 and 9.33 under drought stress, respectively, and 14 µmol H2O2 mg protein-1 min-1 under high temperature. Similarly, ascorbate peroxidase significantly increased in all tolerant accessions due to high temperatures, with ILL6359, ILL7835, and ILL8029 accumulating the highest values with up 50 µmol ascorbate mg protein-1 min-1. In contrast, no significant increase was obtained for all accessions subjected to water stress, although the drought-tolerant accessions accumulated more APX activity (16.59 t to 25.08 µmol ascorbate mg protein-1 min-1) than the sensitive accessions. The accessions ILL6075, ILL7814, and ILL8029 significantly had the highest superoxide dismutase activity under high temperature, while ILL6363, ILL7814, and ILL7835 accumulated the highest values under drought stress, each with 22 to 25 units mg protein-1. Under both stress conditions, ILL7814 and ILL7835 recorded the highest contents in proline (38 to 45 µmol proline/g FW), total flavonoids (0.22 to 0.77 mg QE g-1 FW), total phenolics (7.50 to 8.79 mg GAE g-1 FW), total tannins (5.07 to 20 µg CE g-1 FW), and total antioxidant activity (60 to 70%). Further, ILL7814 and ILL6338 significantly recorded the highest total soluble sugar content under high temperature (71.57 and 74.24 mg g-1, respectively), while ILL7835 achieved the maximum concentration (125 mg g-1) under drought stress. The accessions ILL8029, ILL6104, and ILL7814 had the highest values of reducing sugar under high temperature with 0.62 to 0.79 mg g-1, whereas ILL6075, ILL6363, and ILL6362 accumulated the highest levels of this component under drought stress with 0.54 to 0.66 mg g-1. Overall, our findings contribute to a deeper understanding of the metabolomic responses of lentil to drought and heat stresses, serving as a valuable reference for lentil stress tolerance breeding.

Biochemical and metabolic signatures are fundamental to drought adaptation in PGPR Enterobacter bugandensis WRS7

Drought alone causes more annual loss in crop yield than the sum of all other environmental stresses. There is growing interest in harnessing the potential of stress-resilient PGPR in conferring plant resistance and enhancing crop productivity in drought-affected agroecosystems. A detailed understanding of the complex physiological and biochemical responses will open up the avenues to stress adaptation mechanisms of PGPR communities under drought. It will pave the way for rhizosphere engineering through metabolically engineered PGPR. Therefore, to reveal the physiological and metabolic networks in response to drought-mediated osmotic stress, we performed biochemical analyses and applied untargeted metabolomics to investigate the stress adaptation mechanisms of a PGPR Enterobacter bugendensis WRS7 (Eb WRS7). Drought caused oxidative stress and resulted in slower growth rates in Eb WRS7. However, Eb WRS7 could tolerate drought stress and did not show changes in cell morphology under stress conditions. Overproduction of ROS caused lipid peroxidation (increment in MDA) and eventually activated antioxidant systems and cell signalling cascades, which led to the accumulation of ions (Na+, K+, and Ca2+), osmolytes (proline, exopolysaccharides, betaine, and trehalose), and modulated lipid dynamics of the plasma membranes for osmosensing and osmoregulation, suggesting an osmotic stress adaption mechanism in PGPR Eb WRS7. Finally, GC-MS-based metabolite profiling and deregulated metabolic responses highlighted the role of osmolytes, ions, and intracellular metabolites in regulating Eb WRS7 metabolism. Our results suggest that understanding the role of metabolites and metabolic pathways can be exploited for future metabolic engineering of PGPR and developing bio inoculants for plant growth promotion under drought-affected agroecosystems.

Comparative stress response assessment of PFOS and its alternatives, F-53B and OBS, in wheat: An insight of toxic mechanisms and relative magnitudes

Emerging alternatives to perfluorooctane sulfonate (PFOS), including 6:2 chlorinated polyfluorinated ether sulfonate (F-53B) and p-perfluorous nonenoxybenzene sulfonate (OBS), have been widely detected in the real environment as PFOS restriction. However, the toxicity in plants and the underlying mechanism of F-53B and OBS remain scarce, especially compared to PFOS. PFOS and their emerging alternatives pose significant potential risks to food, especially for crops, safety and human health with the great convenience of high chemical stability. Germination toxicity, oxidative stress biomarkers, and metabolomics were used to compare the relative magnitudes of toxicity of PFOS and its alternatives in wheat (Triticum aestivum L.). PFOS, F-53B, and OBS inhibited wheat germination compared to the control group, with germination inhibition rates of 45.6%, 53.5%, and 64.3% at 400 μM PFOS, F-53B, and OBS exposure, respectively. Moreover, oxidative stress biomarker changes were observed in PFOS, F-53B, and OBS, with OBS being more pronounced. The chlorophyll concentrations in wheat shoots increased, and the anthocyanin concentration decreased along with the increased exposure concentration. Superoxide dismutase (SOD) activity increased in wheat root but decreased in the shoot. Peroxidase (POD) activity and malondialdehyde (MDA) concentration increased, whereas catalase (CAT) activity decreased. Regarding metabolomics, PFOS, F-53B, and OBS exposure (10 μM) significantly altered 85, 133, and 134 metabolites, respectively. According to KEGG enrichment analysis, F-53B specifically affects lipid metabolism, whereas OBS causes an imbalance in amino acid and carbohydrate metabolism. These findings suggested that PFOS, F-53B, and OBS have distinct toxic mechanisms. Thus, our results indicated that the relative size of the toxicity in wheat is as follows: OBS > F-53B > PFOS, and this finding provides a new reference basis for the phytotoxicity assessment of F-53B and OBS.

Molecular and genetic insights into secondary metabolic regulation underlying insect-pest resistance in legumes

Insect pests pose a major threat to agricultural production, resulting in significant economic losses for countries. A high infestation of insects in any given area can severely reduce crop yield and quality. This review examines the existing resources for managing insect pests and highlights alternative eco-friendly techniques to enhance insect pest resistance in legumes. Recently, the application of plant secondary metabolites has gained popularity in controlling insect attacks. Plant secondary metabolites encompass a wide range of compounds such as alkaloids, flavonoids, and terpenoids, which are often synthesized through intricate biosynthetic pathways. Classical methods of metabolic engineering involve manipulating key enzymes and regulatory genes to enhance or redirect the production of secondary metabolites in plants. Additionally, the role of genetic approaches, such as quantitative trait loci mapping, genome-wide association (GWAS) mapping, and metabolome-based GWAS in insect pest management is discussed, also, the role of precision breeding, such as genome editing technologies and RNA interference for identifying pest resistance and manipulating the genome to develop insect-resistant cultivars are explored, highlighting the positive contribution of plant secondary metabolites engineering-based resistance against insect pests. It is suggested that by understanding the genes responsible for beneficial metabolite compositions, future research might hold immense potential to shed more light on the molecular regulation of secondary metabolite biosynthesis, leading to advancements in insect-resistant traits in crop plants. In the future, the utilization of metabolic engineering and biotechnological methods may serve as an alternative means of producing biologically active, economically valuable, and medically significant compounds found in plant secondary metabolites, thereby addressing the challenge of limited availability.

Understanding the Seasonal Effect of Metabolite Production in Terminalia catappa L. Leaves through a Concatenated MS- and NMR-Based Metabolomics Approach

Terminalia catappa L. (Combretaceae) is a medicinal plant that is part of the Brazilian biodiversity; this plant is popularly used for the treatment of a wide range of diseases. To better understand the chemical composition of T. catappa in different seasons, we conducted a thorough study using LC-MS and NMR data analysis techniques. The study helped obtain a chemical profile of the plant ethanolic extracts in different seasons of the year (spring, summer, autumn, and winter). The dereplication of LC-HRMS data allowed the annotation of 90 compounds in the extracts of T. catappa (hydrolyzable tannins, ellagic acid derivatives, and glycosylated flavonoids). Triterpenes and C-glycosyl flavones were the compounds that significantly contributed to differences observed between T. catappa plant samples harvested in autumn/winter and spring, respectively. The variations observed in the compound composition of the plant leaves may be related to processes induced by environmental stress and leaf development. Data fusion applied in the metabolomic profiling study allowed us to identify metabolites with greater confidence, and provided a better understanding regarding the production of specialized metabolites in T. catappa leaves under different environmental conditions, which may be useful to establish appropriate quality criteria for the standardization of this medicinal plant.

Semi-quantitative analysis of cannabinoids in hemp (Cannabis sativa L.) using gas chromatography coupled to mass spectrometry

Background

Hemp (Cannabis sativa L.) is a producer of cannabinoids. These organic compounds are of increasing interest due to their potential applications in the medicinal field. Advances in analytical methods of identifying and quantifying these molecules are needed.

Method

This study describes a new method of cannabinoid separation from plant material using gas chromatography-mass spectrometry (GC-MS) as the analytical tool to detect low abundance cannabinoids that will likely have implications for future therapeutical treatments. A novel approach was adopted to separate trichomes from plant material to analyse cannabinoids of low abundance not observed in raw plant extract. Required plant sample used for analysis was greatly reduced compared to other methods. Derivatisation method was simplified and deconvolution software was utilised to recognise unknown cannabinoid compounds of low abundance.

Results

The method produces well-separated spectra and allows the detection of major and minor cannabinoids. Ten cannabinoids that had available standards could be identified and quantified and numerous unidentified cannabinoids or pathway intermediates based on GC-MS spectra similarities could be extracted and analysed simultaneously with this method.

Conclusions

This is a rapid novel extraction and analytical method from plant material that can identify major and minor cannabinoids using a simple technique. The method will be of use to future researchers seeking to study the multitude of cannabinoids whose values are currently not understood.

Metabolomics as a Prospective Tool for Soybean (Glycine max) Crop Improvement

Global demand for soybean and its products has stimulated research into the production of novel genotypes with higher yields, greater drought and disease tolerance, and shorter growth times. Genetic research may be the most effective way to continue developing high-performing cultivars with desirable agronomic features and improved nutritional content and seed performance. Metabolomics, which predicts the metabolic marker for plant performance under stressful conditions, is rapidly gaining interest in plant breeding and has emerged as a powerful tool for driving crop improvement. The development of increasingly sensitive, automated, and high-throughput analytical technologies, paired with improved bioinformatics and other omics techniques, has paved the way for wide characterization of genetic characteristics for crop improvement. The combination of chromatography (liquid and gas-based) with mass spectrometry has also proven to be an indisputable efficient platform for metabolomic studies, notably plant metabolic fingerprinting investigations. Nevertheless, there has been significant progress in the use of nuclear magnetic resonance (NMR), capillary electrophoresis, and Fourier-transform infrared spectroscopy (FTIR), each with its own set of benefits and drawbacks. Furthermore, utilizing multivariate analysis, principal components analysis (PCA), discriminant analysis, and projection to latent structures (PLS), it is possible to identify and differentiate various groups. The researched soybean varieties may be correctly classified by using the PCA and PLS multivariate analyses. As metabolomics is an effective method for evaluating and selecting wild specimens with desirable features for the breeding of improved new cultivars, plant breeders can benefit from the identification of metabolite biomarkers and key metabolic pathways to develop new genotypes with value-added features.

Mainstreaming orphan millets for advancing climate smart agriculture to secure nutrition and health

The ever-changing climate and the current COVID-19 pandemic compound the problems and seriously impact agriculture production, resulting in socio-economic insecurities and imposing health implications globally. Most of the poor and malnourished population in the developing countries depends on agriculture for food, income, and employment. Impact of climate change together with the COVID-19 outbreak revealed immense problems highlighting the importance of mainstreaming climate-resilient and low input crops with more contemporary agriculture practices. Orphan millets play a vital role in the poor and malnourished population's livelihood, food and nutrition security. Recognizing their unique potential, the United Nations-Food and Agriculture Organization has announced the year 2023 as the "International Year of Millets". However, despite the unique properties for present and future agriculture of orphan millets, their cultivation is declining in many countries. As a result, millets have gained attention from researchers which eventually decelerated "multi-omics" resource generation. This review summarizes the benefits of millets and major barriers/ bottlenecks in their improvement. We also discuss the pre- and post-harvest technologies; policies required to introduce and establish millets in mainstream agriculture. To improve and ensure the livelihood of the poor/malnourished population, intensive efforts are urgently needed in advancing the research and development, implementing pre- and post-harvest technological intervention strategies, and making favorable policies for orphan crops to accomplish food and nutrition security. National and international collaborations are also indispensable to address the uncertain effects of climate change and COVID-19.

Metabolomics reveals key resistant responses in tomato fruit induced by Cryptococcus laurentii

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Cryptococcus laurentii induces resistance through in concert with key metabolic changes in tomato fruit.

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A total of 59 metabolites were differently abundant in C. laurentii-treated tomato fruit.

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Key metabolites chlorogenic acid, caffeic acid and ferulic acid are involved in phenylpropanoid biosynthesis pathway may play a key role in resistance induction by C. Laurentii in tomato.

To investigate the mechanisms underlying inducible resistance in postharvest tomato fruit, non-targeted metabolome analysis was performed to uncover metabolic changes in tomato fruit upon Cryptococcus laurentii treatment. 289 and 149 metabolites were identified in positive and negative ion modes, respectively. A total of 59 metabolites, mainly including phenylpropanoids, flavonoids and phenolic acids, were differently abundant in C. laurentii-treated tomato fruit. Moreover, key metabolites involved in phenylpropanoid biosynthesis pathway, especially chlorogenic acid, caffeic acid and ferulic acid were identified through KEGG enrichment analysis. Enhanced levels of phenolic acids indicated activation of the phenylpropanoid biosynthesis pathway, which is a classic metabolic pathway associated with inducible resistance, suggesting that its activation and consequent metabolic changes contributed to inducible resistence induced by C. laurentii. Our findings would provide new understanding of resistance induction mechanism in tomato fruit from the metabolic perspective, and offer novel insights for new approaches reducing postharvest loss on tomato.

Deep Untargeted Metabolomics Analysis to Further Characterize the Adaptation Response of Gliricidia sepium (Jacq.) Walp. to Very High Salinity Stress

The multipurpose tree Gliricidia sepium (Jacq.) Walp. adapts to a very high level of salt stress (≥20 dS m^-1) and resumes the production of new leaves around 2 weeks after losing all leaves due to abrupt salinity stress. The integration of metabolome and transcriptome profiles from gliricidia leaves points to a central role of the phenylpropanoid biosynthesis pathway in the short-term response to salinity stress. In this study, a deeper untargeted metabolomics analysis of the leaves and roots of young gliricidia plants was conducted to characterize the mechanism(s) behind this adaptation response. The polar and lipidic fractions from leaf and root samples were extracted and analyzed on a UHPLC.ESI.Q-TOF.HRMS system. Acquired data were analyzed using the XCMS Online, and MetaboAnalyst platforms, via three distinct and complementary strategies. Together, the results obtained first led us to postulate that these plants are salt-excluding plants, which adapted to high salinity stress via two salt-excluding mechanisms, starting in the canopy-severe defoliation-and concluding in the roots-limited entry of Na. Besides that, it was possible to show that the phenylpropanoid biosynthesis pathway plays a role throughout the entire adaptation response, starting in the short term and continuing in the long one. The roots metabolome analysis revealed 11 distinct metabolic pathways affected by salt stress, and the initial analysis of the two most affected ones-steroid biosynthesis and lysine biosynthesis-led us also to postulate that the accumulation of lignin and some phytosterols, as well as lysine biosynthesis-but not degradation, play a role in promoting the adaptation response. However, additional studies are necessary to investigate these hypotheses.

Role of Promising Secondary Metabolites to Confer Resistance Against Environmental Stresses in Crop Plants: Current Scenario and Future Perspectives

Plants often face incompatible growing environments like drought, salinity, cold, frost, and elevated temperatures that affect plant growth and development leading to low yield and, in worse circumstances, plant death. The arsenal of versatile compounds for plant consumption and structure is called metabolites, which allows them to develop strategies to stop enemies, fight pathogens, replace their competitors and go beyond environmental restraints. These elements are formed under particular abiotic stresses like flooding, heat, drought, cold, etc., and biotic stress such as a pathogenic attack, thus associated with survival strategy of plants. Stress responses of plants are vigorous and include multifaceted crosstalk between different levels of regulation, including regulation of metabolism and expression of genes for morphological and physiological adaptation. To date, many of these compounds and their biosynthetic pathways have been found in the plant kingdom. Metabolites like amino acids, phenolics, hormones, polyamines, compatible solutes, antioxidants, pathogen related proteins (PR proteins), etc. are crucial for growth, stress tolerance, and plant defense. This review focuses on promising metabolites involved in stress tolerance under severe conditions and events signaling the mediation of stress-induced metabolic changes are presented.

Chemical Profiling of Two Italian Olea europaea (L.) Varieties Subjected to UV-B Stress

The depletion of the stratospheric ozone layer due to natural and/or anthropogenic causes decreases the amount of UV-B radiation filtered, and consequently increases the risk of potential damage to organisms. In the Mediterranean region, high UV-B indices are frequent. Even for species typical of this region, such as the olive tree, the progressive increase in UV-B radiation represents a threat. This work aimed to understand how high UV-B radiation modulates the phenolic and lipophilic profile of olive varieties, and identify metabolites that enhance olive stress tolerance. Two Italian olive varieties were subjected to chronic UV-B stress, and leaves were analyzed by gas and liquid chromatography. The results indicated that the most representative phenolic and lipophilic compounds of Giarraffa and Olivastra Seggianese were readjusted in response to UV-B stress. The Giarraffa variety seemed better suited to prolonged UV-B stress, possibly due to the higher availability of flavonoids that could help control oxidative damage, and the accumulation of hydroxycinnamic acid derivatives that could provide strong UV-B shield protection. In addition, this variety contained higher levels of fatty acids (e.g., palmitic, α-linolenic, and stearic acids), which can help to maintain membrane integrity and accumulate more sorbitol (which may serve as an osmoprotectant or act a free-radical scavenger), terpenes, and long-chain alkanes, providing higher protection against UV-B stress.

Metabolomics profile responses to changing environments in a common bean (Phaseolus vulgaris L.) germplasm collection

Metabolomics is one of the most powerful -omics to assist plant breeding. Despite the recognized genetic diversity in Portuguese common bean germplasm, details on its metabolomics profiles are still missing. Aiming to promote their use and to understand the environment's effect in bean metabolomics profiles, 107 Portuguese common bean accessions, cropped under contrasting environments, were analyzed using spectrophotometric, untargeted and targeted mass spectrometry approaches. Although genotype was the most relevant factor on bean metabolomics profile, a clear genotype × environment interaction was also detected. Multivariate analysis highlighted, on the heat-stress environment, the existence of higher levels of salicylic acid, and lower levels of triterpene saponins. Three clusters were defined within each environment. White accessions presented the lowest content and the colored ones the highest levels of prenol lipids and flavonoids. Sources of interesting metabolomics profiles are now identified for bean breeding, focusing either on local or on broad adaptation.

Bioprospecting as a strategy for conservation and sustainable use of the Brazilian Flora

Abstract In Brazil, research with natural products had a strong impulse when FAPESP supported the creation of the Laboratory of Chemistry of Natural Products of the Institute of Chemistry of USP (1966). In 1999, FAPESP launched the Research Program in the Characterization, Conservation, Restoration and Sustainable Use of Biodiversity (BIOTA-FAPESP), which intensified the sustainable exploitation of biodiversity, and which evolved to form the Biota Network for Bioprospection and Bioassays (BIOprospecTA), which integrates groups from all over the country, optimizing the use of the skills already installed for the bioprospecting of microorganisms, plants, invertebrates, vertebrates and marine organisms. Of the 104 projects related to plant sciences, 35 carried out bioprospection of Brazilian flora, belonging to the areas of Chemistry, Botany, Genetics, Plant Physiology, Plant Morphology, Plant (Chemo)taxonomy, Ecosystem Ecology, Plant Genetics. Physical Sciences, Forest Resources, Forestry Engineering, Agronomy, leading to thousands of publications, engagement of hundreds of students and a deeper understanding of natural products in different biological models through macromolecules analysis aided by computational and spectrometric strategies, in addition to pharmacological evaluations. The development of omics approaches led to a more comprehensive view of the chemical profile of an organism, and enabled integrated and concomitant studies of several samples, and faster annotation of known molecules, through the use of hyphenated and chemometric techniques, and molecular networking. This also helped to overcome the lack of information on the safety and efficacy of herbal preparations, in projects dealing with the standardization of herbal products, according to international standards. The BIOTA-FAPESP program has also focused on environmental aspects, in accordance with the principles of Green Chemistry and has had positive effects on international collaboration, on the number and impact of scientific publications and on partnership with companies, a crucial step to add value and expand the production chain of bioproducts. Also, the compilation, systematization and sharing of data were contemplated with the creation of the NUBBEDB database, of free access, and that integrates with international databases (ACD/labs, American Chemical Society – ACS), helping researchers and companies in the development from different areas of science, technology, strengthening the bioeconomy and subsidizing public policies.

Metabolite Diversity and Metabolic Genome-Wide Marker Association Studies (Mgwas) for Health Benefiting Nutritional Traits in Pearl Millet Grains

As efforts are made to increase food security, millets are gaining increasing importance due to their excellent nutritional credentials. Among the millets, pearl millet is the predominant species possessing several health benefiting nutritional traits in its grain that are helpful in mitigating chronic illnesses such as type−2 diabetes and obesity. In this paper, we conducted metabolomic fingerprinting of 197 pearl millet inbred lines drawn randomly from within the world collection of pearl millet germplasm and report the extent of genetic variation for health benefitting metabolites in these genotypes. Metabolites were extracted from seeds and assessed using flow infusion high-resolution mass spectrometry (FIE-HRMS). Metabolite features (m/z), whose levels significantly differed among the germplasm inbred lines, were identified by ANOVA corrected for FDR and subjected to functional pathway analysis. A number of health-benefiting metabolites linked to dietary starch, antioxidants, vitamins, and lipid metabolism-related compounds were identified. Metabolic genome-wide association analysis (mGWAS) performed using the 396 m/z as phenotypic traits and the 76 K SNP as genotypic variants identified a total of 897 SNPs associated with health benefiting nutritional metabolite at the -log p-value ≤ 4.0. From these associations, 738 probable candidate genes were predicted to have an important role in starch, antioxidants, vitamins, and lipid metabolism. The mGWAS analysis focused on genes involved in starch branching (α-amylase, β-amylase), vitamin-K reductase, UDP-glucuronosyl, and UDP-glucosyl transferase (UGTs), L-ascorbate oxidase, and isoflavone 2′-monooxygenase genes, which are known to be linked to increases in human health benefiting metabolites. We demonstrate how metabolomic, genomic, and statistical approaches can be utilized to pinpoint genetic variations and their functions linked to key nutritional properties in pearl millet, which in turn can be bred into millets and other cereals crops using plant breeding methods.

Metabolomics and Molecular Approaches Reveal Drought Stress Tolerance in Plants

Metabolic regulation is the key mechanism implicated in plants maintaining cell osmotic potential under drought stress. Understanding drought stress tolerance in plants will have a significant impact on food security in the face of increasingly harsh climatic conditions. Plant primary and secondary metabolites and metabolic genes are key factors in drought tolerance through their involvement in diverse metabolic pathways. Physio-biochemical and molecular strategies involved in plant tolerance mechanisms could be exploited to increase plant survival under drought stress. This review summarizes the most updated findings on primary and secondary metabolites involved in drought stress. We also examine the application of useful metabolic genes and their molecular responses to drought tolerance in plants and discuss possible strategies to help plants to counteract unfavorable drought periods.

Metabolomics-Guided Elucidation of Plant Abiotic Stress Responses in the 4IR Era: An Overview

Plants are constantly challenged by changing environmental conditions that include abiotic stresses. These are limiting their development and productivity and are subsequently threatening our food security, especially when considering the pressure of the increasing global population. Thus, there is an urgent need for the next generation of crops with high productivity and resilience to climate change. The dawn of a new era characterized by the emergence of fourth industrial revolution (4IR) technologies has redefined the ideological boundaries of research and applications in plant sciences. Recent technological advances and machine learning (ML)-based computational tools and omics data analysis approaches are allowing scientists to derive comprehensive metabolic descriptions and models for the target plant species under specific conditions. Such accurate metabolic descriptions are imperatively essential for devising a roadmap for the next generation of crops that are resilient to environmental deterioration. By synthesizing the recent literature and collating data on metabolomics studies on plant responses to abiotic stresses, in the context of the 4IR era, we point out the opportunities and challenges offered by omics science, analytical intelligence, computational tools and big data analytics. Specifically, we highlight technological advancements in (plant) metabolomics workflows and the use of machine learning and computational tools to decipher the dynamics in the chemical space that define plant responses to abiotic stress conditions.

Soybean Metabolomics Based in Mass Spectrometry: Decoding the Plant's Signaling and Defense Responses under Biotic Stress

Metabolomics is an omics technology that is extremely valuable to analyze all small-molecule metabolites in organisms. Recent advances in analytical instrumentation, such as mass spectrometry combined with data processing tools, chemometrics, and spectral data libraries, allow plant metabolomics studies to play a fundamental role in the agriculture field and food security. Few studies are found in the literature using the metabolomics approach in soybean plants on biotic stress. In this review, we provide a new perspective highlighting the potential of metabolomics-based mass spectrometry for soybean in response to biotic stress. Furthermore, we highlight the response and adaptation mechanisms of soybean on biotic stress about primary and secondary metabolism. Consequently, we provide subsidies for further studies of the resistance and improvement of the crop.

Metabolomics as a marketing tool for geographical indication products: a literature review

Geographical indication (GI) is used to identify a product's origin when its characteristics or quality are a result of geographical origin, which includes agricultural products and foodstuff. Metabolomics is an “omics” technique that can support product authentication by providing a chemical fingerprint of a biological system, such as plant and plant-derived products. The main purpose of this article is to verify possible contributions of metabolomic studies to the marketing field, mainly for certified regions, through an integrative review of the literature and maps produced by VOSviewer software. The results indicate that studies based on metabolomics approaches can relate specific food attributes to the region’s terroir and know-how. The evidence of this connection, marketing of GIs and metabolomics methods, is viewed as potential tool for marketing purposes (e.g., to assist communication of positive aspects and quality), and legal protection. In addition, our results provide a taxonomic categorization that can guide future marketing research involving metabolomics. Moreover, the results are also useful to government agencies to improve GIs registration systems and promotion strategies.

β-Sitosterol differentially regulates key metabolites for growth improvement and stress tolerance in rice plants during prolonged UV-B stress

BACKGROUND

Elevated ultraviolet-B (UV-B) radiation is potentially deleterious to many organisms specifically crop plants and has become a global challenge. Rice is an exceptionally important staple food which is grown worldwide, and many efforts have been done recently to improve rice varieties against UV-B stress. This current study aims to investigate the effects of exogenous application of β-sitosterol (βSito) on growth improvement and tolerance level of rice plants against prolonged UV-B stress. The physiological and metabolic responses were evaluated in rice plants not supplemented with βSito (Nβ) and those supplemented with βSito (Sβ).

RESULTS

The Nβ and Sβ plants were grown under non-stress (ns) and under prolonged UV-B stress (uvs) conditions and termed as Nβ^ns, Sβ^ns and Nβ^uvs, Sβ^uvs, respectively. The application of βSito contributes positively under non-stress and specifically to UV-B stress in terms of improving numerous physiological parameters associated with growth and development such as shoot and root length, RWC, whole plant biomass, chlorophyll pigments, and photosynthetic-related parameters (Pn, Gs, Tr, WUEi, Fv/Fm, and NPQ) in Sβ compared with Nβ plants. Moreover, enhanced oxidative stress tolerance of Sβ^uvs vs. Nβ^uvs plants under stress was attributed to low levels of ROS and substantial trigger in activities of antioxidant enzymes (SOD, POD, CAT, and APX). Metabolic analysis was performed using GC-TOFMS, which revealed higher accumulation of several key metabolites including organic acids, sugars, amino acids, and others in Sβ^uvs vs. Nβ^uvs plants, which were mainly reduced in Nβ plants under stress vs. non-stress conditions.

CONCLUSION

These results provide useful data regarding the important role of βSito on growth maintenance and modulation of several metabolites associated with osmotic and redox adjustments during UV-B stress tolerance in rice plants. Importantly, βSito-regulated plasticity could further be explored specifically in relation to different environmental stresses in other economically useful crop plants.

Variation in frequency of CQA-tested municipal solid waste compost can alter metabolites in vegetables

The use of compost to enhance plant growth and mineral nutrients composition are extensively studied but not much literature information exists on its influence on plant metabolic profiles. A study was performed to assess a 5-year variable frequency of application of Compost Quality Alliance tested municipal solid waste (MSW) compost effect on metabolic profiles of the edible portions of four different vegetable plants. The plants were lettuce (Latuca sativa cv. Grand Rapids), beets (Beta vulgaris cv. Detroit Supreme), carrot (Daucus carota cv. Nantes) and green beans (Phaseolus vulgaris cv. Golden Wax) grown under a sub-humid continental climate. The treatments were annual, biennial and no (control) applications of the MSW compost. Typically, soil fertility highly increased with the annual application of the MSW compost followed by the biennial application but declined in the control plot. The annually applied MSW compost increased total amino acids in the lettuce, carrot, beets, and green beans by ca. 323%, 109%, 94% and 18% respectively, compared to the control. Overall, total phospholipids were enhanced by the biennially applied MSW compost. Total organic acids in the lettuce, beets, and green beans were altered by the annual and biennial MSW compost applications by ca. 35% and 23%; 6% and 6.4%; and 22% and 65%, respectively compared to the control. A 2-dimension principal component analysis biplot confirmed positive association between the different frequencies of MSW compost application and soil fertility enhancement of plant metabolites. In conclusion, the annual application of MSW compost enhanced amino acids, phospholipids, acylcarnitines, amines and choline but reduced glucose in the lettuce, beets, carrot, and green beans. Further studies to elucidate the mechanisms underpinning such biofortification will be required.

The Dynamic Responses of Oil Palm Leaf and Root Metabolome to Phosphorus Deficiency

Inorganic phosphate (Pi) starvation is an important abiotic constraint that affects plant cellular homeostasis, especially in tropical regions with high acidic soil and less solubilizable Pi. In the current work, oil palm seedlings were hydroponically maintained under optimal Pi-supply and no Pi-supply conditions for 14 days, and metabolites were measured by gas chromatography-mass spectrometry (GC-MS), from leaves and roots, after seven and 14 days of treatment, to investigate biochemical pathways in relation to P-utilizing strategy. After seven days of limited Pi, plant leaves showed increased levels of most soluble sugars, and after 14 days, the sugars' level decrease, except for erythritol, mannose, fructose, and glucose, which showed the highest levels. Rather in root samples, there were different but overlapping alterations, mainly on sugars, amino acids, and organic acids. The leaf sample was shown to have the highest response of sugars with myo-inositol playing a vital role in the redistribution of sugars, while maltose levels increased, indicating active degradation of starch in the root. High levels of glycerol and stearate in both roots and leaves suggest the metabolism of storage lipids for cellular energy during Pi-deficient conditions.

Review: Metabolomics as a prediction tool for plants performance under environmental stress

Metabolomics as a diagnosis tool for plant performance has shown good features for breeding and crop improvement. Additionally, due to limitations in land area and the increasing climate changes, breeding projects focusing on abiotic stress tolerance are becoming essential. Nowadays no universal method is available to identify predictive metabolic markers. As a result, research aims must dictate the best method or combination of methods. To this end, we will introduce the key aspects to consider regarding growth scenarios and sampling strategies and discuss major analytical and data treatment approaches that are available to find metabolic markers of plant performance.

UPLC-ESI-MRM/MS for Absolute Quantification and MS/MS Structural Elucidation of Six Specialized Pyranonaphthoquinone Metabolites From Ventilago harmandiana

Pyranonaphthoquinones (PNQs) are important structural scaffolds found in numerous natural products. Research interest in these specialized metabolites lies in their natural occurrence and therapeutic activities. Nonetheless, research progress has thus far been hindered by the lack of analytical standards and analytical methods for both qualitative and quantitative analysis. We report here that various parts of Ventilago harmandiana are rich sources of PNQs. We developed an ultraperformance liquid chromatography-electrospray ionization multiple reaction monitoring/mass spectrometry method to quantitatively determine six PNQs from leaves, root, bark, wood, and heartwood. The addition of standards in combination with a stable isotope of salicylic acid-D₆ was used to overcome the matrix effect with average recovery of 82% ± 1% (n = 15). The highest concentration of the total PNQs was found in the root (11,902 μg/g dry weight), whereas the lowest concentration was found in the leaves (28 μg/g dry weight). Except for the root, PNQ-332 was found to be the major compound in all parts of V. harmandiana, accounting for ∼48% of the total PNQs quantified in this study. However, PNQ-318A was the most abundant PNQ in the root sample, accounting for 27% of the total PNQs. Finally, we provide novel MS/MS spectra of the PNQs at different collision induction energies: 10, 20, and 40 eV (POS and NEG). For structural elucidation purposes, we propose complete MS/MS fragmentation pathways of PNQs using MS/MS spectra at collision energies of 20 and 40 eV. The MS/MS spectra along with our discussion on structural elucidation of these PNQs should be very useful to the natural products community to further exploring PNQs in V. harmandiana and various other sources.

Metabolomic Profiling of Drought-Tolerant and Susceptible Peanut (Arachis hypogaea L.) Genotypes in Response to Drought Stress

Peanut is frequently constrained by extreme environmental conditions such as drought. To reveal the involvement of metabolites, TAG 24 (drought-tolerant) and JL 24 (drought-sensitive) peanut genotypes were investigated under control and 20% PEG 6000-mediated water scarcity conditions at the seedling stage. Samples were analyzed by gas chromatography-mass spectrometry (GC-MS) to identify untargeted metabolites and targeted metabolites, i.e., polyamines and polyphenols by high-performance liquid chromatography (HPLC) and ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), respectively. The principal component analysis (PCA), partial least-squares discriminant analysis (PLS-DA), heat map, and cluster analysis were applied to the metabolomics data obtained by the GC-MS technique to determine the important metabolites for drought tolerance. Among 46 resulting metabolites, pentitol, phytol, xylonic acid, d-xylopyranose, stearic acid, and d-ribose were important drought-responsive metabolites. Agmatine and cadaverine were present in TAG 24 leaves and roots, respectively, during water-deficit conditions and believed to be the potential polyamines for drought tolerance. Polyphenols such as syringic acid and vanillic acid were produced more in the leaves of TAG 24, while catechin production was high in JL 24 during stress conditions. Seven metabolic pathways, namely, galactose metabolism, starch and sucrose metabolism, fructose and mannose metabolism, pentose and glucuronate interconversion, propanoate metabolism, amino sugar and nucleotide sugar metabolism, and biosynthesis of unsaturated fatty acids were significantly affected by water-deficit conditions. This study provides valuable information about the metabolic response of peanut to drought stress and metabolites identified, which encourages further study by transcriptome and proteomics to improve drought tolerance in peanut.

Physiological and Metabolite Reconfiguration of Olea europaea to Cope and Recover from a Heat or High UV-B Shock

To understand how olives reconfigure their metabolism to face stress shock episodes, plants from the economically relevant olive (Olea europaea cv. Cobrançosa) were exposed to high UV-B radiation (UV-B, 12 kJ m^-2 d^-1) or heat shock (HS, 40 °C) for two consecutive days. The physiological responses and some important lipophilic compounds were evaluated immediately (day 0) and 30 days after UV-B or HS episodes. Both treatments induced a reduction of the olive physiological performance, particularly increasing cell membrane damages and proline pool and at the same time reducing chlorophyll levels, the quantum yield of photosystem II (Φ_PSII), and the efficiency of excitation energy capture by open photosystem II (PSII) reaction centers (F'_v/F'_m). Nevertheless, the HS episode caused more adverse effects, additionally reducing the pool of protective pigments (carotenoids) and the maximum efficiency of PSII (with F₀ increase). In the UV-B treatment, despite the higher lipid peroxidation, the activation of some stress protective mechanisms (e.g., increase of NPQ and carotenoids and remobilization of some metabolites, such as phytol and proline) might have contributed to avoiding photoinhibition. Thirty days after stress relief, the performance of olives from both treatments recovered similarly, in part due to the metabolites' adjustments that contributed to strengthened stress protection (an increase of long-chain alkanes) and provided energy (through the use of soluble sugars, mannitol, and myo-inositol) for re-establishment. Other metabolites, like anthocyanins and squalene, also have an important role in responding specifically to HS or UV-B recovery for helping in the oxidative damage control. These data contribute to understanding how young olive plants may deal with climatic episodes when being transferred from nurseries to field orchards, under the actual context of climate change.

Complexity of active medicinal ingredients in radix scutellariae with sodium hydrosulfite exposure

Both plants and animals are living things made up of similar cells as well as organelles, and their essence of life is the same. However, plants face more environmental stress than animals and generate excessive reactive oxygen species (ROS), a group of small molecules that can harm proteins, necessitating distinctive metabolic processes. Secondary metabolites in plants are a group of chemical components that can eliminate ROS and can also exhibit medicinal properties; therefore, herbal medicines are often closely linked to the ecological significance of secondary metabolites. Why plants contain so many, not few, active medicinal ingredients is unknown. The root of Scutellaria baicalensis, a popular herbal medicine, is rich in various flavonoids with diverse structural features. Sodium hydrosulfite (Na₂S₂O₄) can produce O˙^-₂ radicals and induce physical conditions under environmental stress. Using UHPLC-ESI-Q-TOF-MS/MS analysis, a total of 25 different compounds were identified in the roots of S. baicalensis between the Na₂S₂O₄ groups and suitable conditions. Based on the results of the t-test (P<0.05) performed for the groups and ions with values of VIP ≥ 2, the most significantly different chemical markers with Na₂S₂O₄ treatment were shikimic acid, citric acid, baicalin, wogonoside, baicalein, wogonin, 3,5,7,2',6'-pentahydroxyflavanone, 5,2',6'-trihydroxy-7,8-dimethoxy flavone, chrysin, eriodictyol, 5,8-dihydroxy-6,7 -dimethoxy flavone, skullcapflavone Ⅱ, and 5,7-dihydroxy-6,8,2',3'-tetrame thoxyflavone, and most of them were free flavonoids with many phenolic hydroxyl or methoxyl groups and characteristically high antioxidant activities. S. baicalensis roots modified their ability to eliminate ROS and maintained the equilibrium of ROS through the multitudinous biosynthesis and conversion of flavonoids, which is similar to the equilibrium established by an intricate buffer solution and perfectly explains the diversity and complexity of medicinal plant ingredients.

GC-MS based metabolomic approach to understand nutraceutical potential of Cannabis seeds from two different environments

Cannabis sativa L. is a valuable plant that has regained its importance for medicinal use. Gas chromatography-mass spectrometry based untargeted metabolomic study was conducted in seeds of two accessions from different environments. A total of 236 metabolites were observed, and 43 metabolites were found differentially significant (p ≤ 0.05) in both the accessions. Based on the qualitative and quantitative accumulation of the nutraceutically important amino acids, cannabinoids, alkaloids, and fatty acids, the high altitude temperate Himalayan accession (CAN2) was found to have an advantage over the low altitude subtropical accession (CAN1). Seed oil from CAN2 showed the exclusive presence of linoleic acid and α- linolenic acid. The reducing power and DNA nicking assay on the methanolic extracts suggested higher antioxidant and nutraceutical potential in CAN2 and corroborated with the metabolic content of phenols and flavonoids. The environmental effect on the antioxidant and nutraceutical value in seeds is further discussed.