Evolution of secondary metabolites from an ecological and molecular phylogenetic perspective

Leaf Endophytes Relationship with Host Metabolome Expression in Tropical Gymnosperms

Plant-microbe interactions play a pivotal role in shaping host fitness, especially concerning chemical defense mechanisms. In cycads, establishing direct correlations between specific endophytic microbes and the synthesis of highly toxic defensive phytochemicals has been challenging. Our research delves into the intricate relationship between plant-microbe associations and the variation of secondary metabolite production in two closely related Zamia species that grow in distinct habitats; terrestrial and epiphytic. Employing an integrated approach, we combined microbial metabarcoding, which characterize the leaf endophytic bacterial and fungal communities, with untargeted metabolomics to test if the relative abundances of specific microbial taxa in these two Zamia species were associated with different metabolome profiles. The two species studied shared approximately 90% of the metabolites spanning diverse biosynthetic pathways: alkaloids, amino acids, carbohydrates, fatty acids, polyketides, shikimates, phenylpropanoids, and terpenoids. Co-occurrence networks revealed positive associations among metabolites from different pathways, underscoring the complexity of their interactions. Our integrated analysis demonstrated to some degree that the intraspecific variation in metabolome profiles of the two host species was associated with the abundance of bacterial orders Acidobacteriales and Frankiales, as well as the fungal endophytes belonging to the orders Chaetothyriales, Glomerellales, Heliotiales, Hypocreales, and Sordariales. We further associate individual metabolic similarity with four specific fungal endophyte members of the core microbiota, but no specific bacterial taxa associations were identified. This study represents a pioneering investigation to characterize leaf endophytes and their association with metabolomes in tropical gymnosperms, laying the groundwork for deeper inquiries into this complex domain.

Metabolic Activation and Cytotoxicity of Gramine Mediated by CYP3A in Rats

Gramine (GRM), which occurs in Gramineae plants, has been developed to be a biological insecticide. Exposure to GRM was reported to induce elevations of serum ALT and AST in rats, but the mechanisms of the observed hepatotoxicity have not been elucidated. The present study aimed to identify reactive metabolites that potentially participate in the toxicity. In rat liver microsomal incubations fortified with glutathione or N-acetylcysteine, one oxidative metabolite (M1), one glutathione conjugate (M2), and one N-acetylcysteine conjugate (M3) were detected after exposure to GRM. The corresponding conjugates were detected in the bile and urine of rats after GRM administration. CYP3A was the main enzyme mediating the metabolic activation of GRM. The detected GSH and NAC conjugates suggest that GRM was metabolized to a quinone imine intermediate. Both GRM and M1 showed significant toxicity to rat primary hepatocytes.

Enough is enough: feedback control of specialized metabolism

Recent advances in our understanding of plant metabolism have highlighted the significance of specialized metabolites in the regulation of gene expression associated with biosynthetic networks. This opinion article focuses on the molecular mechanisms of small-molecule-mediated feedback regulation at the transcriptional level and its potential modes of action, including metabolite signal perception, the nature of the sensor, and the signaling transduction mechanisms leading to transcriptional and post-transcriptional regulation, based on evidence available from plants and other kingdoms of life. We also discuss the challenges associated with identifying the occurrences, effects, and localization of small molecule-protein interactions. Further understanding of small-molecule-controlled metabolic fluxes will enable rational design of transcriptional regulation systems in metabolic engineering to produce high-value specialized metabolites.

Investigation of Health Effects of Major Phenolic Compounds in Foods: Extraction Processes, Analytical Approaches and Applications

The escalating costs of healthcare services and a growing awareness of personal health responsibilities have led individuals to explore natural methods alongside conventional medicines for health improvement and disease prevention. The aging global population is experiencing increased health needs, notably related to conditions like diabetes, heart disease, and hypertension. Lifestyle-related diseases, poor dietary habits, and sedentary lifestyles underscore the importance of foods containing nutrients that can aid in preventing and managing these diseases. Phenolic compounds, a fundamental group of phytochemicals, are prominent in the chemical diversity of the natural world and are abundant in functional foods. Widely distributed in various plant parts, these compounds exhibit important functional and sensory properties, including color, taste, and aroma. Their diverse functionalities, particularly antioxidant activity, play a crucial role in mitigating cellular oxidative stress, potentially reducing damage associated with serious health issues such as cardiovascular disease, neurodegenerative disea23ses, and cancer. Phenolic compounds exist in different forms, some combined with glycosides, impacting their biological effects and absorption. Approximately 8000 polyphenols isolated from plants offer significant potential for natural medicines and nutritional supplements. Therefore, their extraction process and selective and sensitive food determination are very important. This review focuses on the extraction processes, analytical methods, and health effects of major phenolic compounds in foods. The examination encompasses a comprehensive analysis of analytical approaches and their applications in elucidating the presence and impact of these compounds on human health.

Twenty Years of 1H NMR Plant Metabolomics: A Way Forward toward Assessment of Plant Metabolites for Constitutive and Inducible Defenses to Biotic Stress

Metabolomics has become an important tool in elucidating the complex relationship between a plant genotype and phenotype. For over 20 years, nuclear magnetic resonance (NMR) spectroscopy has been known for its robustness, quantitative capabilities, simplicity, and cost-efficiency. 1H NMR is the method of choice for analyzing a broad range of relatively abundant metabolites, which can be used for both capturing the plant chemical profile at one point in time and understanding the pathways that underpin plant defense. This systematic Review explores how 1H NMR-based plant metabolomics has contributed to understanding the role of various compounds in plant responses to biotic stress, focusing on both primary and secondary metabolites. It clarifies the challenges and advantages of using 1H NMR in plant metabolomics, interprets common trends observed, and suggests guidelines for method development and establishing standard procedures.

Agronomic, Nutritional Traits, and Alkaloids of Lupinus albus, Lupinus angustifolius and Lupinus luteus Genotypes: Effect of Sowing Dates and Locations

Lupins (Lupinus spp.) are legumes with high relevance for the sustainability of agricultural systems as they improve the soil quality, namely, through the fixation of atmospheric nitrogen, and have good adaptability to different climates and soil conditions. Besides, they possess high nutritive value, especially due to the high protein content of the seeds. Nevertheless, the plants' productivity and metabolism can be influenced by the genotype, the edaphoclimatic conditions, and the sowing practices. In this work, the effect of edaphoclimatic conditions and sowing dates on the productivity, nutritional factors, and alkaloids of the seeds of L. albus cv. Estoril, L. angustifolius cv. Tango, and L. luteus cv. Cardiga was evaluated. High variability in the seeds and protein productions, nutritional traits, and alkaloid content related to the species was observed, along with a significant effect of the location. Lupinus albus cv. Estoril showed a good compromise between productivity and low alkaloid content, being an interesting genotype for food and feed use in the conditions of this trial.

Perennial Baki™ Bean Safety for Human Consumption: Evidence from an Analysis of Heavy Metals, Folate, Canavanine, Mycotoxins, Microorganisms and Pesticides

Global food production relies on annual grain crops. The reliability and productivity of these crops are threatened by adaptations to climate change and unsustainable rates of soil loss associated with their cultivation. Perennial grain crops, which do not require planting every year, have been proposed as a transformative solution to these challenges. Perennial grain crops typically rely on wild species as direct domesticates or as sources of perenniality in hybridization with annual grains. Onobrychis spp. (sainfoins) are a genus of perennial legumes domesticated as ancient forages. Baki™ bean is the tradename for pulses derived from sainfoins, with ongoing domestication underway to extend demonstrated benefits to sustainable agriculture. This study contributes to a growing body of evidence characterizing the nutritional quality of Baki™ bean. Through two studies, we investigated the safety of Baki™ bean for human consumption. We quantified heavy metals, folate, and canavanine for samples from commercial seed producers, and we quantified levels of mycotoxins, microorganisms, and pesticides in samples from a single year and seed producer, representing different varieties and production locations. The investigated analytes were not detectable or occurred at levels that do not pose a significant safety risk. Overall, this study supports the safety of Baki™ bean for human consumption as a novel pulse crop.

Traditional medicinal use is linked with apparency, not specialized metabolite profiles in the order Caryophyllales

PREMISE

Better understanding of the relationship between plant specialized metabolism and traditional medicine has the potential to aid in bioprospecting and untangling of cross-cultural use patterns. However, given the limited information available for metabolites in most plant species, understanding medicinal use-metabolite relationships can be difficult. The order Caryophyllales has a unique pattern of lineages of tyrosine- or phenylalanine-dominated specialized metabolism, represented by mutually exclusive anthocyanin and betalain pigments, making Caryophyllales a compelling system to explore the relationship between medicine and metabolites by using pigment as a proxy for dominant metabolism.

METHODS

We compiled a list of medicinal species in select tyrosine- or phenylalanine-dominant families of Caryophyllales (Nepenthaceae, Polygonaceae, Simmondsiaceae, Microteaceae, Caryophyllaceae, Amaranthaceae, Limeaceae, Molluginaceae, Portulacaceae, Cactaceae, and Nyctaginaceae) by searching scientific literature until no new uses were recovered. We then tested for phylogenetic clustering of uses using a "hot nodes" approach. To test potential non-metabolite drivers of medicinal use, like how often humans encounter a species (apparency), we repeated the analysis using only North American species across the entire order and performed phylogenetic generalized least squares regression (PGLS) with occurrence data from the Global Biodiversity Information Facility (GBIF).

RESULTS

We hypothesized families with tyrosine-enriched metabolism would show clustering of different types of medicinal use compared to phenylalanine-enriched metabolism. Instead, wide-ranging, apparent clades in Polygonaceae and Amaranthaceae are overrepresented across nearly all types of medicinal use.

CONCLUSIONS

Our results suggest that apparency is a better predictor of medicinal use than metabolism, although metabolism type may still be a contributing factor.

Essentials in the acquisition, interpretation, and reporting of plant metabolite profiles

Plant metabolite profiling reveals the diversity of secondary or specialized metabolites in the plant kingdom with its hundreds of thousands of species. Specialized plant metabolites constitute a vast class of chemicals posing significant challenges in analytical chemistry. In order to be of maximum scientific relevance, reports dealing with these compounds and their source species must be transparent, make use of standards and reference materials, and be based on correctly and traceably identified plant material. Essential aspects in qualitative plant metabolite profiling include: (i) critical review of previous literature and a reasoned sampling strategy; (ii) transparent plant sampling with wild material documented by vouchers in public herbaria and, optimally, seed banks; (iii) if possible, inclusion of generally available reference plant material; (iv) transparent, documented state-of-the art chemical analysis, ideally including chemical reference standards; (v) testing for artefacts during preparative extraction and isolation, using gentle analytical methods; (vi) careful chemical data interpretation, avoiding over- and misinterpretation and taking into account phytochemical complexity when assigning identification confidence levels, and (vii) taking all previous scientific knowledge into account in reporting the scientific data. From the current stage of the phytochemical literature, selected comments and suggestions are given. In the past, proposed revisions of botanical taxonomy were sometimes based on metabolite profiles, but this approach ("chemosystematics" or "chemotaxonomy") is outdated due to the advent of DNA sequence-based phylogenies. In contrast, systematic comparisons of plant metabolite profiles in a known phylogenetic framework remain relevant. This approach, known as chemophenetics, allows characterizing species and clades based on their array of specialized metabolites, aids in deducing the evolution of biosynthetic pathways and coevolution, and can serve in identifying new sources of rare and economically interesting natural products.

Complementary roles of two classes of defense chemicals in white spruce against spruce budworm

MAIN CONCLUSION

Monoterpenes and phenolics play distinct roles in defending white spruce trees from insect defoliators. Monoterpenes contribute to the toxicity of the foliage, deterring herbivory, whereas phenolics impede budworm growth. This study demonstrates the complex interplay between monoterpenes and phenolics and their collective influence on the defense strategy of white spruce trees against a common insect defoliator. Long-lived coniferous trees display considerable variations in their defensive chemistry. The impact of these defense phenotype variations on insect herbivores of the same species remains to be thoroughly studied, mainly due to challenges in replicating the comprehensive defense profiles of trees under controlled conditions. This study methodically examined the defensive properties of foliar monoterpenes and phenolics across 80 distinct white spruce families. These families were subsequently grouped into two chemotypes based on their foliar monoterpene concentrations. To understand the separate and combined effects of these classes on tree defenses to the eastern spruce budworm, we conducted feeding experiments using actual defense profiles from representative families. Specifically, we assessed budworm response when exposed to substrates amended with phenolics alone or monoterpenes. Our findings indicate that the ratios and amounts of monoterpenes and phenolics present in the white spruce foliage influence the survival of spruce budworms. Phenotypes associated with complete larval mortality exhibited elevated ratios (ranging from 0.4 to 0.6) and concentrations (ranging from 1143 to 1796 ng mg-1) of monoterpenes. Conversely, families characterized by higher phenolic ratios (ranging from 0.62 to 0.77) and lower monoterpene concentrations (ranging from 419 to 985 ng mg-1) were less lethal to the spruce budworm. Both classes of defense compounds contribute significantly to the overall defensive capabilities of white spruce trees. Monoterpenes appear critical in determining the general toxicity of foliage, while phenolics play a role in slowing budworm development, thereby underscoring their collective importance in white spruce defenses.

Chemical-tag-based semi-annotated metabolomics facilitates gene identification and specialized metabolic pathway elucidation in wheat

The importance of metabolite modification and species-specific metabolic pathways has long been recognized. However, linking the chemical structure of metabolites to gene function in order to explore the genetic and biochemical basis of metabolism has not yet been reported in wheat (Triticum aestivum). Here, we profiled metabolic fragment enrichment in wheat leaves and consequently applied chemical-tag-based semi-annotated metabolomics in a genome-wide association study in accessions of wheat. The studies revealed that all 1,483 quantified metabolites have at least one known functional group whose modification is tailored in an enzyme-catalyzed manner and eventually allows efficient candidate gene mining. A Triticeae crop-specific flavonoid pathway and its underlying metabolic gene cluster were elucidated in further functional studies. Additionally, upon overexpressing the major effect gene of the cluster TraesCS2B01G460000 (TaOMT24), the pathway was reconstructed in rice (Oryza sativa), which lacks this pathway. The reported workflow represents an efficient and unbiased approach for gene mining using forward genetics in hexaploid wheat. The resultant candidate gene list contains vast molecular resources for decoding the genetic architecture of complex traits and identifying valuable breeding targets and will ultimately aid in achieving wheat crop improvement.

Effects of leaf herbivory and autumn seasonality on plant secondary metabolites: A meta-analysis

Plant secondary metabolites (PSMs) are produced by plants to overcome environmental challenges, both biotic and abiotic. We were interested in characterizing how autumn seasonality in temperate and subtropical climates affects overall PSM production in comparison to herbivory. Herbivory is commonly measured between spring to summer when plants have high resource availability and prioritize growth and reproduction. However, autumn seasonality also challenges plants as they cope with limited resources and prepare survival for winter. This suggests a potential gap in our understanding of how herbivory affects PSM production in autumn compared to spring/summer. Using meta-analysis, we recorded overall production of 22 different PSM subgroups from 58 published papers to calculate effect sizes from herbivory studies (absence to presence) and temperate to subtropical seasonal studies (summer to autumn), while considering other variables (e.g., plant type, increase in time since herbivory, temperature, and precipitation). We also compared production of five phenolic PSM subgroups - hydroxybenzoic acids, flavan-3-ols, flavonols, hydrolysable tannins, and condensed tannins. We wanted to detect a shared response across all PSMs and found that herbivory increased overall PSM production in herbaceous plants. Herbivory was also found to have a positive effect on individual PSM subgroups, such as flavonol production, while autumn seasonality was found to have a positive effect on flavan-3-ol and condensed tannin production. We discuss how these responses might stem from plants producing some PSMs constitutively, whereas others are induced only after herbivory, and how plants produce metabolites with higher costs only during seasons when other resources for growth and reproduction are less available, while other phenolic PSM subgroups serve more than one function for plants and such functions can be season dependent. The outcome of our meta-analysis is that autumn seasonality changes some PSM production differently from herbivory, and we see value in further investigating seasonality-herbivory interactions with plant chemical defense.

Anti-rheumatic potential vis-à-vis aconitine and hypaconitine content analysis in different Aconitum spp. from Sikkim Himalayas (India)

Aconitum spp. are important medicinal plants mentioned in Ayurveda as Ativisa or Vatsanabha. The present study aims to evaluate anti-rheumatic potential in seven Aconitum species and correlation with aconitine and hypaconitine content. Anti-rheumatic potential was analyzed through in vitro xanthine oxidase inhibition, anti-inflammatory and ROS scavenging assays; and quantification of aconitine and hypaconitine with RP-HPLC method validated as per ICH guidelines. The findings reveal that A. palmatum possessed the most promising response (IC50 =12.68±0.15 μg/ml) followed by A. ferox (IC50 =12.912±1.87 μg/ml) for xanthin oxidase inhibition. We observed a wide variation in aconitine and hypaconitine content ranging from 0.018 %-1.37 % and 0.0051 %-0.077 % respectively on dry weight basis. Aconitine and hypaconitine showed moderate positive correlation (r=0.68 and 0.59 respectively) with anti-rheumatic potential. The study identifies potential alternative species of Aconitum that can help in sustainable availability of quality raw material.

Bioactive Analysis of Antibacterial Efficacy and Antioxidant Potential of Aloe barbadensis Miller Leaf Extracts and Exploration of Secondary Metabolites Using GC-MS Profiling

Aloe barbadensis Miller (ABM) is a traditional medicinal plant all over the world. Numerous studies were conducted to exhibit its medicinal properties and most of them were concentrated on its metabolites against human pathogens. The current research work evaluates the attributes of different polar-based extracts (ethanol, methanol, ethyl acetate, acetone, hexane, and petroleum ether) of dried Aloe barbadensis leaf (ABL) to investigate its phytochemical constituents, antioxidant potential (DPPH, ABTS), phenolic, tannin, flavonoid contents, identification of bioactive compounds, and functional groups by gas chromatography-mass spectrometry (GC-MS) and fourier transform infrared spectroscopy (FT-IR) respectively, and comparing antibacterial efficacy against human pathogens, aquatic bacterial pathogens, and zoonotic bacteria associated with fish and human. The present results showed that the methanolic extract of ABL showed higher antioxidant activity (DPPH-59.73 ± 2.01%; ABTS-74.1 ± 1.29%), total phenolic (10.660 ± 1.242 mg GAE/g), tannin (7.158 ± 0.668 mg TAE/g), and flavonoid content (49.545 ± 1.928 µg QE/g) than that of other solvent extracts. Non-polar solvents hexane and petroleum ether exhibited lesser activity among the extracts. In the case of antibacterial activity, higher inhibition zone was recorded in methanol extract of ABL (25.00 ± 0.70 mm) against Aeromonas salmonicida. Variations in antibacterial activity were observed depending on solvents and extracts. In the current study, polar solvents revealed higher antibacterial activity when compared to the non-polar and the mid-polar solvents. Diverse crucial bioactive compounds were detected in GC-MS analysis. The vital compounds were hexadecanoic acid (30.69%) and 2-pentanone, 4-hydroxy-4-methyl (23.77%) which are responsible for higher antioxidant and antibacterial activity. Similar functional groups were identified in all the solvent extracts of ABL with slight variations in the FT-IR analysis. Polar-based solvent extraction influenced the elution of phytocompounds more than that of the other solvents used in this study. The obtained results suggested that the ABM could be an excellent source for antioxidant and antibacterial activities and can also serve as a potential source of effective bioactive compounds to combat human as well as aquatic pathogens.

Allelopathy and allelobiosis: efficient and economical alternatives in agroecosystems

Chemical interactions in plants often involve plant allelopathy and allelobiosis. Allelopathy is an ecological phenomenon leading to interference among organisms, while allelobiosis is the transmission of information among organisms. Crop failures and low yields caused by inappropriate management can be related to both allelopathy and allelobiosis. Therefore, research on these two phenomena and the role of chemical substances in both processes will help us to understand and upgrade agroecosystems. In this review, substances involved in allelopathy and allelobiosis in plants are summarized. The influence of environmental factors on the generation and spread of these substances is discussed, and relationships between allelopathy and allelobiosis in interspecific, intraspecific, plant-micro-organism, plant-insect, and mechanisms, are summarized. Furthermore, recent results on allelopathy and allelobiosis in agroecosystem are summarized and will provide a reference for the future application of allelopathy and allelobiosis in agroecosystem.

Asparagine-rich protein (NRP) mediates stress response by regulating biosynthesis of plant secondary metabolites in Arabidopsis

The plant-specific stress response protein NRP (asparagine-rich protein) is characterized by an asparagine-rich domain at its N-terminus and a conserved development and cell death (DCD) domain at its C-terminus. Previous transcriptional studies and phenotypic analyses have demonstrated the involvement of NRP in response to severe stress conditions, such as high salt and ER Endoplasmic reticulum-stress. We have recently identified distinct roles for NRP in biotic- and abiotic-stress signaling pathways, in which NRP interacts with different signaling proteins to change their subcellular localizations and stability. Here, to further explore the function of NRP, a transcriptome analysis was carried out on nrp1nrp2 knock-out lines at different life stages or under different growing conditions. The most significant changes in the transcriptome at both stages and conditions turned out to be the induction of the synthesis of secondary metabolites (SMs). Such an observation implicates that NRP is a general stress-responsive protein involved in various challenges faced by plants during their life cycle, which might involve a broad alteration in the distribution of SMs.

Geographical distribution-based differentiation of cultivated Angelica dahurica, exploring the relationship between the secretory tract and the quality

Based on geographical distribution, cultivated Chinese Angelica dahurica has been divided into Angelica dahurica cv. 'Hangbaizhi' (HBZ) and Angelica dahurica cv. 'Qibaizhi' (QBZ). Long-term geographical isolation has led to significant quality differences between them. The secretory structure in medicinal plants, as a place for accumulating effective constituents and information transmission to the environment, links the environment with the quality of medicinal materials. However, the secretory tract differences between HBZ and QBZ has not been revealed. This study aimed to explore the relationship between the secretory tract and the quality of two kinds of A. dahurica. Root samples were collected at seven development phases. High-Performance Liquid Chromatography (HPLC) and Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI) were used for the content determination and spatial location of coumarins. Paraffin section was used to observe and localize the root secretory tract. Origin, CaseViewer, and HDI software were used for data analysis and image processing. The results showed that compared to QBZ, HBZ, with better quality, has a larger area of root secretory tracts. Hence, the root secretory tract can be included in the quality evaluation indicators of A. dahurica. Additionally, DESI-MSI technology was used for the first time to elucidate the temporal and spatial distribution of coumarin components in A. dahurica root tissues. This study provides a theoretical basis for the quality evaluation and breeding of improved varieties of A. dahurica and references the DESI-MSI technology used to analyze the metabolic differences of various compounds, including coumarin and volatile oil, in different tissue parts of A. dahurica.

Microbial degradation of plant toxins

Plants produce a variety of secondary metabolites in response to biotic and abiotic stresses. Although they have many functions, a subclass of toxic secondary metabolites mainly serve plants as deterring agents against herbivores, insects, or pathogens. Microorganisms present in divergent ecological niches, such as soil, water, or insect and rumen gut systems have been found capable of detoxifying these metabolites. As a result of detoxification, microbes gain growth nutrients and benefit their herbivory host via detoxifying symbiosis. Here, we review current knowledge on microbial degradation of toxic alkaloids, glucosinolates, terpenes, and polyphenols with an emphasis on the genes and enzymes involved in breakdown pathways. We highlight that the insect-associated microbes might find application in biotechnology and become targets for an alternative microbial pest control strategy.

The Interactions between Two Fungal Endophytes Epicoccum layuense R2-21 and Alternaria alternata XHYN2 and Grapevines (Vitis vinifera) with De Novo Established Symbionts under Aseptic Conditions

In this study, we focused on grapevine-endophyte interactions and reprogrammed secondary metabolism in the host plant due to defense against the colonization of endophytes. Thus, the transcriptional responses of tissue cultured grapevine seedlings (Vitis vinifera L. cv.: Cabernet Sauvignon) to two fungal endophytes Epicoccum layuense R2-21 (Epi R2-21) and Alternaria alternata XHYN2 (Alt XHYN2) at three different time points (6 h, 6 d, 15 d) were analyzed. As expected, a total of 5748 and 5817 differentially expressed genes (DEGs) were separately initiated in Epi R2-21 and Alt XHYN2 symbiotic tissue cultured seedlings compared to no endophyte treatment. The up-regulated DEGs at all time points in Epi R2-21- or Alt XHYN2-treated seedlings were mainly enriched in the flavonoid biosynthesis, phenylpropanoid biosynthesis, phenylalanine metabolism, stilbenoid, diarylheptanoid and gingerol biosynthesis, and circadian rhythm-plant pathways. In addition, the up-regulated DEGs at all sampling times in Alt XHYN2-treated tissue cultured seedlings were enriched in the plant-pathogen interaction pathway, but appeared in Epi R2-21 symbiotic seedlings only after 15 d of treatment. The down-regulated DEGs were not enriched in any KEGG pathways after 6 h inoculation for Epi R2-21 and Alt XHYN2 treatments, but were enriched mainly in photosynthesis-antenna proteins and plant hormone signal transduction pathways at other sampling times. At three different time points, a total of 51 DEGs (all up-regulated, 1.33-10.41-fold) were involved in secondary metabolism, and 22 DEGs (all up-regulated, 1.01-8.40-fold) were involved in defense responses in endophytic fungi symbiotic tissue cultured seedlings. The protein-protein interaction (PPI) network demonstrated that genes encoding CHS (VIT_10s0042g00920, VIT_14s0068g00920, and VIT_16s0100g00910) and the VIT_11s0065g00350 gene encoding CYP73A mediated the defense responses, and might induce more defense-associated metabolites. These results illustrated the activation of stress-associated secondary metabolism in the host grapevine during the establishment of fungi-plant endophytism. This work provides avenues for reshaping the qualities and characteristics of wine grapes utilizing specific endophytes and better understanding plant-microbe interactions.

Evolutionary studies of the bHLH transcription factors belonging to MBW complex: their role in seed development

BACKGROUND AND AIMS

The MBW complex consist of proteins belonging to three major families (MYB, bHLH and WDR) involved in various processes throughout plant development: epidermal cell development, mucilage secretory cells and flavonoid biosynthesis. Recently, it has been reported that TT8, encoding a bHLH transcription factor, is involved in the biosynthesis of flavonoids in the seed coat and it also plays a role in bypassing the postzygotic barrier resulting from an unbalance in genetic loads of the parental lines. Here, we focus on the functional evolution, in seed development, of the bHLH proteins that are part of the MBW complex, complemented with a literature review.

METHODS

Phylogenetic analyses performed across seed plants and expression analyses in the reproductive tissues of four selected angiosperms (Arabidopsis thaliana, Brassica napus, Capsella rubella and Solanum lycopersicum) allow us to hypothesize on the evolution of its functions.

KEY RESULTS

TT8 expression in the innermost layer of the seed coat is conserved in the selected angiosperms. However, except for Arabidopsis, TT8 is also expressed in ovules, carpels and fruits. The homologues belonging to the sister clade of TT8, EGL3/GL3, involved in trichome development, are expressed in the outermost layer of the seed coat, suggesting potential roles in mucilage.

CONCLUSIONS

The ancestral function of these genes appears to be flavonoid biosynthesis, and the conservation of TT8 expression patterns in the innermost layer of the seed coat in angiosperms suggests that their function in postzygotic barriers might also be conserved. Moreover, the literature review and the results of the present study suggest a sophisticated association, linking the mechanisms of action of these genes to the cross-communication activity between the different tissues of the seed. Thus, it provides avenues to study the mechanisms of action of TT8 in the postzygotic triploid block, which is crucial because it impacts seed development in unbalanced crosses.

Metabolome expression in Eucryphia cordifolia populations: Role of seasonality and ecological niche centrality hypothesis

The ecological niche centrality hypothesis states that population abundance is determined by the position in the ecological niche, expecting higher abundances towards the center of the niche and lower at the periphery. However, the variations in the conditions that favor the persistence of populations between the center and the periphery of the niche can be a surrogate of stress factors that are reflected in the production of metabolites in plants. In this study we tested if metabolomic similarity and diversity in populations of the tree species Eucryphia cordifolia Cav. vary according to their position with respect to the structure of the ecological niche. We hypothesize that populations growing near the centroid should exhibit lower metabolites diversity than plants growing at the periphery of the niche. The ecological niche of the species was modeled using correlative approaches and bioclimatic variables to define central and peripheral localities from which we chose four populations to obtain their metabolomic information using UHPLC-DAD-QTOF-MS. We observed that populations farther away from the centroid tend to have higher metabolome diversity, thus supporting our expectation of the niche centrality hypothesis. Nonetheless, the Shannon index showed a marked variation in metabolome diversity at the seasonal level, with summer and autumn being the periods with higher metabolite diversity compared to winter and spring. We conclude that both the environmental variation throughout the year in combination with the structure of the ecological niche are relevant to understand the variation in expression of metabolites in plants.

Phytochemical diversity impacts herbivory in a tropical rainforest tree community

Metabolomics provides an unprecedented window into diverse plant secondary metabolites that represent a potentially critical niche dimension in tropical forests underlying species coexistence. Here, we used untargeted metabolomics to evaluate chemical composition of 358 tree species and its relationship with phylogeny and variation in light environment, soil nutrients, and insect herbivore leaf damage in a tropical rainforest plot. We report no phylogenetic signal in most compound classes, indicating rapid diversification in tree metabolomes. We found that locally co-occurring species were more chemically dissimilar than random and that local chemical dispersion and metabolite diversity were associated with lower herbivory, especially that of specialist insect herbivores. Our results highlight the role of secondary metabolites in mediating plant-herbivore interactions and their potential to facilitate niche differentiation in a manner that contributes to species coexistence. Furthermore, our findings suggest that specialist herbivore pressure is an important mechanism promoting phytochemical diversity in tropical forests.

In-silico studies of Brassica oleracea active compounds and their role in thyroid peroxidase activity

Cabbage, a leafy vegetable that is widely consumed across the globe, holds a significant place within the Brassica family. For almost a century, its potential anti-thyroid effects have captured attention. The presence of compounds such as thiocyanate and goitrin in cabbage has been extensively investigated for their ability to impede sodium-iodide symporter and thyroid peroxidase (TPO) activities. The present study is focused on uncovering the active constituents in cabbage that could interact with TPO, while also examining their stability under cooking temperatures. Employing molecular docking and molecular dynamic simulation techniques, we quantified the binding strength of phytochemicals present in cabbage with the target. Out of the 60 compounds identified in cabbage leaves, only 18 exhibited docking scores surpassing those of the commercially available anti-thyroid drug, methimazole. These chosen compounds were studied for binding free energy and pharmacokinetic properties. A specific compound, gamma-Terpinene, classified as a monoterpene, emerged as noteworthy due to its alignment with all criteria and the highest observed binding free energy compared to others. Furthermore, we explored the stability of gamma-Terpinene at 373.15K (cooking temperature) and observed its susceptibility to degradation. This might contribute to the relatively diminished anti-thyroid effects of cabbage when consumed in cooked form. Consequently, our findings suggest that the consumption of cooked cabbage could be more conducive to maintaining normal thyroid function, as opposed to its raw counterpart.Communicated by Ramaswamy H. Sarma.

Current Fungal Taxonomy and Developments in the Identification System

A functional identification system is the core and basis of fungal taxonomy, which provides sufficient diagnostic characteristics for species delimitation. Phenotype-based identification systems have exhibited significant drawbacks, such as being laborious and time-consuming. Thus, a molecular-based identification system (rDNA, DNA fingerprint, etc.) is proposed for application to fungi that lack reliable morphological characteristics. High Throughput Sequencing also makes great contributions to fungal taxonomy. However, the formal naming of nonculturable fungi from environmental sequencing is a significant challenge. Biochemical profile-based identification systems have outstanding value in fungal taxonomy and can occasionally be indispensable. This method utilizes biomarker metabolites and proteins that are expected to be unequivocal and stable. Of these, Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry has become the method of choice for chemotaxonomy. In sum, these described identification systems cannot solve all problems of species delimitation, and considerable attention to the updating of fungal nomenclature, standardization of techniques, knowledge sharing, and dissemination will be necessary.

Moringa oleifera Use in Maintaining Oral Health and Its Potential Use in Regenerative Dentistry

Phytomedicine refers to the use of naturally derived products to cure and mitigate human conditions. Natural products have the advantages of causing minimum side effects, being biocompatible, available, and economical, with a wide array of biological activities. Reports have described the use of natural products with antimicrobial and anti-inflammatory properties to treat oral conditions and promote wound healing. Moringa oleifera, known as the "drumstick" or "horseradish" tree, is believed to have medicinal properties regarding a range of medical conditions, though there is limited information on its use in oral medicine. This narrative review focuses on the use of Moringa extracts in the management of oral conditions, including oral infections, inflammatory conditions, the remineralization of hard tissues, oral wound healing, and tissue regeneration, drawing from both in vitro and in vivo studies which indicate that the potential of Moringa extracts in supporting dentin-pulp regeneration after caries or trauma is worthy of more careful consideration.

Screening of 20 species from Lamiaceae family based on phytochemical analysis, antioxidant activity and HPLC profiling

The Lamiaceae family encompasses numerous species highly valued for their applications in medicine, food, and cosmetics. In order to screen the Lamiaceae family and discover new sources of phytochemicals and antioxidants, we comprehensively evaluated 20 species from this family, including Phlomis herba-venti, P. tuberosa, P. olivieri, P. kurdica, Nepeta sp., N. cataria, N. saccharata, Stachys sp., S. inflata, Scutellaria albida, Marrubium parviflora, Mentha pulegium, Thymus kotschyanus, Lamium album, Salvia officinalis, S. multicaulis, S. macrochlamys, S. candidissima, S. verticillata, and S. nemorosa. The aerial parts of these species were analyzed to determine their total phenolic (TPC) and flavonoid (TFC) contents, total tannin content (TTC), ascorbic acid content (AAC), antioxidant capacity (assessed by FRAP and DPPH assays), and polyphenolic components (by HPLC). The phytochemical compounds and antioxidant properties varied widely among different species. The highest concentrations of TPC (70.93 mg GAE/g DW), TFC (17.89 mg Que/g DW), TTC (6.49 mg TAE/100 g), and AAC (1.15 mg AA/g DW), as well as the greatest antioxidant activity, were observed in different Salvia species. Additionally, chlorogenic and rosmarinic acids were the primary phenolic compounds identified in the extracts from the investigated Lamiaceae family. According to Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA), three groups of species were identified, characterized by variations in phytochemical composition and antioxidant capacity. The results obtained can provide new natural sources of phytochemicals and antioxidant agents, particularly from Salvia species, for the advancement of new products in the food, agricultural, cosmetics and health industries.

Chemical composition variation of essential oils of Copaifera langsdorffii Desf. from different vegetational formations

This study aims to provide information about the chemical profile of the essential oil from C. langsdorffii resin in areas of Cerradão, Carrasco, and Humid Forest. In order to obtain the essential oils, oil-resin was submitted to hydrodistillation process, and the chemical components were analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Twenty-six constituents were identified in the essential oil of C. langsdorffii resin, of which 12 were present in Cerradão, 15 in Carrasco and 18 in Humid Forest, with β-bisabolene, caryophyllene oxide, γ-muurolene, α-caryophyllene and β-caryophyllene common to the three phytophysiognomies. Among the studied areas, the resin collection varied from 2.652 g to 20.263 g, while the essential oil yield varied from 2.216 % to 11.764 %. A concentration range of 0.60 % to 84.57 % was recorded among the compounds in the three study areas. There was variation in chemical composition both among phytophysiognomies and among individuals from the same location, where β-caryophyllene showed to be the majority for all areas studied, being present in all individuals from Cerradão, Carrasco and Humid Forest.

Decoupling subgenomes within hybrid lavandin provide new insights into speciation and monoterpenoid diversification of Lavandula

Polyploidization and transposon elements contribute to shape plant genome diversity and secondary metabolic variation in some edible crops. However, the specific contribution of these variations to the chemo-diversity of Lamiaceae, particularly in economic shrubs, is still poorly documented. The rich essential oils (EOs) of Lavandula plants are distinguished by monoterpenoids among the main EO-producing species, L. angustifolia (LA), L. × intermedia (LX) and L. latifolia (LL). Herein, the first allele-aware chromosome-level genome was assembled using a lavandin cultivar 'Super' and its hybrid origin was verified by two complete subgenomes (LX-LA and LX-LL). Genome-wide phylogenetics confirmed that LL, like LA, underwent two lineage-specific WGDs after the γ triplication event, and their speciation occurred after the last WGD. Chloroplast phylogenetic analysis indicated LA was the maternal source of 'Super', which produced premium EO (higher linalyl/lavandulyl acetate and lower 1,8-cineole and camphor) close to LA. Gene expression, especially the monoterpenoid biosynthetic genes, showed bias to LX-LA alleles. Asymmetric transposon insertions in two decoupling 'Super' subgenomes were responsible for speciation and monoterpenoid divergence of the progenitors. Both hybrid and parental evolutionary analysis revealed that LTR (long terminal repeat) retrotransposon associated with AAT gene loss cause no linalyl/lavandulyl acetate production in LL, and multi-BDH copies retained by tandem duplication and DNA transposon resulted in higher camphor accumulation of LL. Advances in allelic variations of monoterpenoids have the potential to revolutionize future lavandin breeding and EO production.

Correlating Eucalyptus leaf metabolomics with preference of the bronze bug, Thaumastocoris peregrinus

Eucalyptus species are among the most planted trees in forestry production, an ever-increasing commercial activity worldwide. Forestry expansion demands a continuous search for preventive and sanitary measures against pests and diseases. Massive application of phytosanitary products is incompatible with the forestry sector, so forest health management must be based on other principles. In this context, studies on insect plant relationships mediated by plant metabolites may contribute information relevant to plant resistance and genotype selection. In this study, we analyzed the leaf metabolome of four Eucalyptus species commonly planted in southern South America, to correlate this chemical information with feeding preference of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae), an important pest of eucalypt plantations. Gas chromatography mass spectrometry analyses were performed on polar and non-polar leaf extracts from Eucalyptus globulus, Eucalyptus grandis, Eucalyptus robusta, and Eucalyptus tereticornis (Myrtaceae). Feeding preferences were assessed in two-choice laboratory bioassays resulting in a preference gradient of the four plant species. Moreover, a performance bioassay where we contrasted survival and development time between the most and least preferred plants, showed a clear correlation with preference both in survival and developmental time of the most susceptible nymph instar. We found that species with high or low feeding preferences differ significantly in several foliar metabolites, which may be acting as feeding stimulants or deterrents for T. peregrinus. These findings may provide useful criteria for choosing Eucalyptus genotypes when planting in bronze bug infested areas.

Teline monspessulana Can Harm the Chilean Native Tree Nothofagus obliqua: Effects on Germination and Initial Growth

Teline monspessulana is highly invasive in several countries around the world. This species pressurizes and displaces several native and endemic tree species in south-central Chile such as Nothofagus obliqua, the native species of greatest timber interest. We determined the effects induced by allelochemical stress of T. monspessulana on N. obliqua germination and initial growth. Germination was evaluated under in vitro conditions and in natural substrate obtained from sites inhabited by N. obliqua and from nearby areas invaded by T. monspessulana. Controls irrigated with tap water and treatments with aqueous extracts of aerial organs of the invasive species were used. Morphometric and morphological variables were evaluated, and the composition of alkaloids and phenols from the plant organs used for the aqueous extracts was determined. The substrates were also chemically characterized. Allelochemicals synthesized by T. monspessulana caused germination and growth inhibition and tissue-level alterations, as well as leaf and root damage in N. obliqua seedlings. In the aerial organs of T. monspessulana, the quinolizidine alkaloids aphylline, caulophylline, anagyrine, and sophocarpine were mainly detected. In addition, 21 phenolic compounds were identified, including gallic acid, vanillic acid, chlorogenic acid, p-coumaric acid, and quercetin. The phytotoxic potential of T. monspessulana can compromise the natural multiplication of N. obliqua and its survival from its first phenological stages. This interdisciplinary study model facilitated the clarification of the plant-plant relationship mediated by allelochemicals. The model can be replicated to investigate other interspecific interactions between invasive and native species.

Modern drug discovery using ethnobotany: A large-scale cross-cultural analysis of traditional medicine reveals common therapeutic uses

For millennia, numerous cultures and civilizations have relied on traditional remedies derived from plants to treat a wide range of conditions and ailments. Here, we systematically analyzed ethnobotanical patterns across taxonomically related plants, demonstrating that congeneric medicinal plants are more likely to be used for treating similar indications. Next, we reconstructed the phytochemical space covered by medicinal plants to reveal that (i) taxonomically related medicinal plants cover a similar phytochemical space, and (ii) chemical similarity correlates with similar therapeutic usage. Lastly, we present several case scenarios illustrating how mining this information can be used for drug discovery applications, including: (i) investigating taxonomic hotspots around particular indications, (ii) exploring shared patterns of congeneric plants located in different geographic areas, but which have been used to treat the same indications, and (iii) showing the concordance between ethnobotanical patterns among non-taxonomically related plants and the presence of shared bioactive phytochemicals.

Leaf metabolic traits reveal hidden dimensions of plant form and function

The metabolome is the biochemical basis of plant form and function, but we know little about its macroecological variation across the plant kingdom. Here, we used the plant functional trait concept to interpret leaf metabolome variation among 457 tropical and 339 temperate plant species. Distilling metabolite chemistry into five metabolic functional traits reveals that plants vary on two major axes of leaf metabolic specialization-a leaf chemical defense spectrum and an expression of leaf longevity. Axes are similar for tropical and temperate species, with many trait combinations being viable. However, metabolic traits vary orthogonally to life-history strategies described by widely used functional traits. The metabolome thus expands the functional trait concept by providing additional axes of metabolic specialization for examining plant form and function.

The Impact and Invasive Mechanisms of Pueraria montana var. lobata, One of the World's Worst Alien Species

Pueraria montana var. lobata is native to East Asia, and was introduced to many countries due to its potential for multiple uses. This species escaped under the management conditions soon after its introduction, and became a harmful weed species. This species has been listed in the top 100 of the world's worst invasive alien species. P. montana stands expand quickly and threaten the native flora and fauna including microbiota. This species affects the concentration of carbon and nitrogen in soil and aquatic environments, and increases the amount of pollutants in the local atmosphere. Its infestation also causes serious economic losses on forestry and agriculture. Its characteristics of fast growth, thick canopy structure, enormous vegetative reproduction, and adaptative ability to the various environmental conditions may contribute to the invasiveness and naturalization of this species. The characteristics of P. montana regarding their defense functions against their natural enemies and pathogens, and allelopathy may also contribute to the invasiveness of this species. Potential allelochemicals such as xanthoxins, p-coumaric acid, caffeic acid, methyl caffeate and daidzein, and two isoflavones with anti-virus activity were identified in this species. In addition, fewer herbivore insects were found in the introduced ranges. These characteristics of P. montana may be involved in the invasive mechanisms of the species. This is the first review article focusing on the invasive mechanisms of this species.

Bioreactor configurations for adventitious root culture: recent advances toward the commercial production of specialized metabolites

In vitro plant cell and organ cultures are appealing alternatives to traditional methods of producing valuable specialized metabolites for use as: pharmaceuticals, food additives, cosmetics, perfumes, and agricultural chemicals. Cell cultures have been adopted for the production of specialized metabolites in certain plants. However, in certain other systems, adventitious roots are superior to cell suspension cultures as they are organized structures that accumulate high levels of specialized metabolites. The cultivation of adventitious roots has been investigated in various bioreactor systems, including: mechanically agitated, pneumatically agitated, and modified bioreactors. The main relevance and importance of this work are to develop a long-lasting industrial biotechnological technology as well as to improve the synthesis of these metabolites from the plant in vitro systems. These challenges are exacerbated by: the peculiarities of plant cell metabolism, the complexity of specialized metabolite pathways, the proper selection of bioreactor systems, and bioprocess optimization. This review's major objective is to analyze several bioreactor types for the development of adventitious roots, as well as the advantages and disadvantages of each type of bioreactor, and to describe the strategies used to increase the synthesis of specialized metabolites. This review also emphasizes current advancements in the field, and successful instances of scaled-up cultures and the generation of specialized metabolites for commercial purposes are also covered.

Exploring the antibacterial, antidiabetic, and anticancer potential of Mentha arvensis extract through in-silico and in-vitro analysis

BACKGROUND

Mentha arvensis has been utilized in diverse traditional medicines as an antidiabetic, anticarcinogenic, antiallergic, antifungal, and antibacterial agent. In this work, we have explored the phytochemical analyses and pharmacological potential of Mentha arvensis using both in silico and in vitro approaches for drug discovery.

METHODS

To determine the extract with the highest potential for powerful bioactivity, ethanol was used as the solvent. The phytochemical components of the extracts were quantified using liquid chromatography-mass spectrometry analysis. The potential bioactivities of extracts and lead phytocompounds, including their antibacterial, cytotoxic, and anti-diabetic effects, were evaluated.

RESULTS

The compounds oleanolic acid, rosmarinic acid, luteolin, isoorientin, and ursolic acid have been identified through liquid chromatography mass spectrometry analysis. Based on antimicrobial research, it has been found that the Mentha arvensis extract shows potential activity against K. pneumoniae which was 13.39 ± 0.16. Mentha arvensis has demonstrated a greater degree of efficacy in inhibiting α-glucosidase, with an inhibition rate of 58.36 ± 0.12, and in inhibiting α-amylase, with an inhibition rate of 42.18 ± 0.83. The growth of HepG2 cells was observed to be significantly suppressed upon treatment with extracts obtained from Mentha arvensis. Finally, In-silico methods demonstrated that the Luteolin and Rosmarinic acid exhibit acceptable drug-like characteristics. Furthermore, Molecular docking studies further demonstrated that both compounds have strong potential to inhibit the active sites of therapeutically relevant enzymes involved in Diabetes, Bacterial infections, and Cancer.

CONCLUSIONS

The results of this study suggest that the Mentha arvensis extract possesses potent pharmacological potentials, particularly in terms of antibacterial, anti-diabetic, and cytotoxic effects. Particularly, Luteolin and Rosmarinic acid were identified as the top contenders for potential bioactivity with acceptable drug-like properties.

Primary and Secondary Metabolites in Lotus japonicus

Lotus japonicus is a leguminous model plant used to gain insight into plant physiology, stress response, and especially symbiotic plant-microbe interactions, such as root nodule symbiosis or arbuscular mycorrhiza. Responses to changing environmental conditions, stress, microbes, or insect pests are generally accompanied by changes in primary and secondary metabolism to account for physiological needs or to produce defensive or signaling compounds. Here we provide an overview of the primary and secondary metabolites identified in L. japonicus to date. Identification of the metabolites is mainly based on mass spectral tags (MSTs) obtained by gas chromatography linked with tandem mass spectrometry (GC-MS/MS) or liquid chromatography-MS/MS (LC-MS/MS). These MSTs contain retention index and mass spectral information, which are compared to databases with MSTs of authentic standards. More than 600 metabolites are grouped into compound classes such as polyphenols, carbohydrates, organic acids and phosphates, lipids, amino acids, nitrogenous compounds, phytohormones, and additional defense compounds. Their physiological effects are briefly discussed, and the detection methods are explained. This review of the exisiting literature on L. japonicus metabolites provides a valuable basis for future metabolomics studies.

Chemical constituents and antifungal potential of Attalea geraensis Barb. Rodr. (Arecaceae) palm leaves, a species native to the Cerrado of Brazil

Fungal diseases, especially those that affect the root systems of plants, caused by Rhizoctonia and Macrophomina are limiting factors for achieving high crop yields. Alternatives to controlling fungi with chemical products drive the search for new options for bioactive compounds from plants. Attalea geraensis, a palm tree from the Brazilian Cerrado, is rich in flavonoids with antifungal actions. The objective of this work is to identify the chemical classes present in the ethanolic extract of green leaves of A. geraensis and determine the antifungal potential of the extract against isolates of Macrophomina phaseolina (Tassi) Goid. and Rhizoctonia solani JG Kühn. Phytochemical prospection, flavonoid dereplication, and antifungal activity were carried out of the ethanolic extract of the green leaves of A. geraensis harvested in the Cerrado area of Brazil. Steroids, triterpenes, saponins, and anthraquinones are described here for the first time for the leaves of A. geraensis. The flavonoids quercetin, isorhamnetin, 3,7-dimethylquercetin, quercetin 3-galactoside, 5,7-dihydroxy-2-(4-hydroxy-3-methoxyphenyl)-3-{[3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}-4H-chromen-4-one, rhamnazin 3-galactoside, keioside, and rhamnazin 3-rutinoside were identified. Of these, only quercetin and isorhamnetin had already been identified in the leaves of A. geraensis. The results show a fungistatic potential for the species. The diversity of flavonoids present in the leaves of A. geraensis may be the result of a synergistic action between fungus and plant or there could be an antagonistic effect between flavonoids and the other identified chemical classes.

Phytochemical analysis for ten Peruvian Mentheae (Lamiaceae) by liquid chromatography associated with high resolution mass spectrometry

The profile of secondary metabolites in ten members of tribe Mentheae (Nepetoideae, Lamiaceae) from Peru by liquid chromatography associated with high resolution mass spectrometry, is presented. Salvianolic acids and their precursors were found, particularly rosmarinic acid, caffeic acid ester derivatives, as well as a diversity of free and glycosylated flavonoids as main substances. At all, 111 structures were tentatively identified.

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.

Population-Related Variability in Qualitative and Quantitative Secondary Metabolite Profile of Gentianella austriaca (A. & J. Kern.) Holub

Phytochemical profiling of six natural populations of Gentianella austriaca was performed by HPLC identification and quantification of a number of secondary metabolites, and evaluation of time series of peak areas by chemometric analysis. Phytochemical analysis of G. austriaca revealed the presence of iridoids, flavone-C-glucosides and xanthones. Twelve secondary metabolites were identified in the aerial parts, roots and seeds, including swertiamarin (SWM), gentiopicrin (GP), sweroside (SWZ), isoorientin (ISOOR), swertisin (SWE), demethylbellidifolin-8-O-glucoside (DMB-8-O-glc), bellidifolin-8-O-glucoside (BDF-8-O-glc), mangiferin (MGF), corymbiferin (CBF), corymbiferin-1-O-glucoside (CBF-1-O-glc), bellidifolin (BDF) and campestroside. Multivariate statistical analyses showed relatively low variability among populations according to secondary metabolite content. However, some pharmacologically important compounds were found in higher amounts in a few populations, which could be useful for conservation and future biotechnological procedures.

Nuts and berries from agroforestry systems in temperate regions can form the foundation for a healthier human diet and improved outcomes from diet-related diseases

Agroforestry is a specific type of agroecosystem that includes trees and shrubs with the potential to yield nutrient-rich products that contribute to human health. This paper reviews the literature on the human health benefits of tree nut and berry species commonly associated with agroforestry systems of the United States, considering their potential for preventing certain diet-related diseases. Emphasis is placed on those diseases that are most closely associated with poor outcomes from COVID-19, as they are indicators of confounding health prognoses. Results indicate that tree nuts reduce the risk of coronary heart disease, and walnuts (Juglans species) are particularly effective because of their unique fatty acid profile. Berries that are grown on shrubs have the potential to contribute to mitigation of hypertension, prevention of Type II diabetes, and reduced risk of cardiovascular disease. To optimize human health benefits, plant breeding programs can focus on the traits that enhance the naturally-occurring phytochemicals, through biofortification. Value-added processing techniques should be selected and employed to preserve the phytonutrients, so they are maintained through the point of consumption. Agroforestry systems can offer valuable human health outcomes for common diet-related diseases, in addition to providing many environmental benefits, particularly if they are purposefully designed with that goal in mind. The food system policies in the U.S. might be reoriented to prioritize these food production systems based on the health benefits.

Effects of tomato inoculation with the entomopathogenic fungus Metarhizium brunneum on spider mite resistance and the rhizosphere microbial community

Entomopathogenic fungi have been well exploited as biocontrol agents that can kill insects through direct contact. However, recent research has shown that they can also play an important role as plant endophytes, stimulating plant growth, and indirectly suppressing pest populations. In this study, we examined the indirect, plant-mediated, effects of a strain of entomopathogenic fungus, Metarhizium brunneum on plant growth and population growth of two-spotted spider mites (Tetranychus urticae) in tomato, using different inoculation methods (seed treatment, soil drenching and a combination of both). Furthermore, we investigated changes in tomato leaf metabolites (sugars and phenolics), and rhizosphere microbial communities in response to M. brunneum inoculation and spider mite feeding. A significant reduction in spider mite population growth was observed in response to M. brunneum inoculation. The reduction was strongest when the inoculum was supplied both as seed treatment and soil drench. This combination treatment also yielded the highest shoot and root biomass in both spider mite-infested and non-infested plants, while spider mite infestation increased shoot but reduced root biomass. Fungal treatments did not consistently affect leaf chlorogenic acid and rutin concentrations, but M. brunneum inoculation via a combination of seed treatment and soil drenching reinforced chlorogenic acid (CGA) induction in response to spider mites and under these conditions the strongest spider mite resistance was observed. However, it is unclear whether the M. brunneum-induced increase in CGA contributed to the observed spider mite resistance, as no general association between CGA levels and spider mite resistance was observed. Spider mite infestation resulted in up to two-fold increase in leaf sucrose concentrations and a three to five-fold increase in glucose and fructose concentrations, but these concentrations were not affected by fungal inoculation. Metarhizium, especially when applied as soil drench, impacted the fungal community composition but not the bacterial community composition which was only affected by the presence of spider mites. Our results suggest that in addition to directly killing spider mites, M. brunneum can indirectly suppress spider mite populations on tomato, although the underlying mechanism has not yet been resolved, and can also affect the composition of the soil microbial community.

A developmental gradient reveals biosynthetic pathways to eukaryotic toxins in monocot geophytes

Numerous eukaryotic toxins that accumulate in geophytic plants are valuable in the clinic, yet their biosynthetic pathways have remained elusive. A lead example is the >150 Amaryllidaceae alkaloids (AmAs) including galantamine, an FDA-approved treatment for Alzheimer's disease. We show that while AmAs accumulate to high levels in many tissues in daffodils, biosynthesis is localized to nascent, growing tissue at the base of leaves. A similar trend is found for the production of steroidal alkaloids (e.g. cyclopamine) in corn lily. This model of active biosynthesis enabled elucidation of a complete set of biosynthetic genes for the production of AmAs. Taken together, our work sheds light on the developmental and enzymatic logic of diverse alkaloid biosynthesis in daffodil. More broadly, it suggests a paradigm for biosynthesis regulation in monocot geophytes where plants are protected from herbivory through active charging of newly formed cells with eukaryotic toxins that persist as aboveground tissue develops.

Dietary Oncopharmacognosy as a Crosswalk between Precision Oncology and Precision Nutrition

While diet and nutrition are modifiable risk factors for many chronic and infectious diseases, their role in cancer prevention and control remains under investigation. The lack of clarity of some diet-cancer relationships reflects the ongoing debate about the relative contribution of genetic factors, environmental exposures, and replicative errors in stem cell division as determinate drivers of cancer risk. In addition, dietary guidance has often been based upon research assuming that the effects of diet and nutrition on carcinogenesis would be uniform across populations and for various tumor types arising in a specific organ, i.e., that one size fits all. Herein, we present a paradigm for investigating precision dietary patterns that leverages the approaches that led to successful small-molecule inhibitors in cancer treatment, namely understanding the pharmacokinetics and pharmacodynamics of small molecules for targeting carcinogenic mechanisms. We challenge the scientific community to refine the paradigm presented and to conduct proof-in-concept experiments that integrate existing knowledge (drug development, natural products, and the food metabolome) with developments in artificial intelligence to design and then test dietary patterns predicted to elicit drug-like effects on target tissues for cancer prevention and control. We refer to this precision approach as dietary oncopharmacognosy and envision it as the crosswalk between the currently defined fields of precision oncology and precision nutrition with the goal of reducing cancer deaths.

Nematicidal Potential of Thymol against Meloidogyne javanica (Treub) Chitwood

Root-knot nematodes (RKN; Meloidogyne spp.) are obligatory endoparasites with worldwide distribution which cause severe damage to agricultural crops. The present study aimed to define the nematicidal activity of thymol on different life stages of the root-knot nematode Meloidogyne javanica (Treub) Chitwood, at concentrations of 37.5-1000 μL/L. This study is the first to report the effect of thymol on egg differentiation and also its vapor and sublethal concentration activities. A mortality of greater than 90% of M. javanica second-stage juveniles (J2s) occurred after 96 h of exposure at a concentration of 500 μL/L. At this concentration, thymol inhibited 59.7% of nematode hatching. In addition, the use of thymol at sublethal concentrations reduced the number of females per gram in tomato roots in a pot test, as well as inhibiting egg differentiation. On the contrary, no nematostatic effects were observed in paralysis bioassays. The results presented here indicate that the use of thymol may show its potential as a source of a new sustainable nematicidal product.

A conserved hymenopteran-specific family of cytochrome P450s protects bee pollinators from toxic nectar alkaloids

Many plants produce chemical defense compounds as protection against antagonistic herbivores. However, how beneficial insects such as pollinators deal with the presence of these potentially toxic chemicals in nectar and pollen is poorly understood. Here, we characterize a conserved mechanism of plant secondary metabolite detoxification in the Hymenoptera, an order that contains numerous highly beneficial insects. Using phylogenetic and functional approaches, we show that the CYP336 family of cytochrome P450 enzymes detoxifies alkaloids, a group of potent natural insecticides, in honeybees and other hymenopteran species that diverged over 281 million years. We linked this function to an aspartic acid residue within the main access channel of CYP336 enzymes that is highly conserved within this P450 family. Together, these results provide detailed insights into the evolution of P450s as a key component of detoxification systems in hymenopteran species and reveal the molecular basis of adaptations arising from interactions between plants and beneficial insects.

Biochemistry and genetics of floral scent: a historical perspective

Floral scent plays a crucial role in the reproductive process of many plants. Humans have been fascinated by floral scents throughout history, and have transported and traded floral scent products for which they have found multiple uses, such as in food additives, hygiene and perfume products, and medicines. Yet the scientific study of how plants synthesize floral scent compounds began later than studies on most other major plant metabolites, and the first report of the characterization of an enzyme responsible for the synthesis of a floral scent compound, namely linalool in Clarkia breweri, a California annual, appeared in 1994. In the almost 30 years since, enzymes and genes involved in the synthesis of hundreds of scent compounds from multiple plant species have been described. This review recapitulates this history and describes the major findings relating to the various aspects of floral scent biosynthesis and emission, including genes and enzymes and their evolution, storage and emission of scent volatiles, and the regulation of the biochemical processes.

Season, storage and extraction method impact on the phytochemical profile of Terminalia ivorensis

BACKGROUND

Terminalia ivorensis (TI) is used in West African ethnomedicine for the treatment of conditions including ulcers, malaria and wounds. Despite its widespread use, the phytochemical profile of TI remains largely undetermined. This research investigated the effects of extraction method, season, and storage conditions on the phytochemical composition of TI to contribute towards understanding the potential benefits.

METHODS

TI bark was collected in September 2014, September 2018 and February 2018 during the rainy or dry seasons in Eastern Region, Ghana. Samples were extracted sequentially with organic solvents (petroleum ether, chloroform, ethyl acetate and ethanol) or using water (traditional). Metabolites were identified by liquid chromatography-mass spectrometry/mass spectrometry and compared statistically by ANOVA.

RESULTS

A total of 82 different phytochemicals were identified across all samples. A greater yield of the major phytochemicals (44%, p < 0.05) was obtained by water as compared with organic extraction. There was also a higher concentration of metabolites present in cold (63%, p < 0.05) compared with hot water extraction. A significantly (p < 0.05) higher number of phytochemicals were identified from TI collected in the dry (85%) compared to the rainy season (69%). TI bark stored for four years retained 84% of the major phytochemicals.

CONCLUSION

This work provides important information on composition and how this is modified by growing conditions, storage and method of extraction informing progress on the development of TI as a prophylactic formulation or medicine.

Ethylene and Jasmonates Signaling Network Mediating Secondary Metabolites under Abiotic Stress

Plants are sessile organisms that face environmental threats throughout their life cycle, but increasing global warming poses an even more existential threat. Despite these unfavorable circumstances, plants try to adapt by developing a variety of strategies coordinated by plant hormones, resulting in a stress-specific phenotype. In this context, ethylene and jasmonates (JAs) present a fascinating case of synergism and antagonism. Here, Ethylene Insensitive 3/Ethylene Insensitive-Like Protein1 (EIN3/EIL1) and Jasmonate-Zim Domain (JAZs)-MYC2 of the ethylene and JAs signaling pathways, respectively, appear to act as nodes connecting multiple networks to regulate stress responses, including secondary metabolites. Secondary metabolites are multifunctional organic compounds that play crucial roles in stress acclimation of plants. Plants that exhibit high plasticity in their secondary metabolism, which allows them to generate near-infinite chemical diversity through structural and chemical modifications, are likely to have a selective and adaptive advantage, especially in the face of climate change challenges. In contrast, domestication of crop plants has resulted in change or even loss in diversity of phytochemicals, making them significantly more vulnerable to environmental stresses over time. For this reason, there is a need to advance our understanding of the underlying mechanisms by which plant hormones and secondary metabolites respond to abiotic stress. This knowledge may help to improve the adaptability and resilience of plants to changing climatic conditions without compromising yield and productivity. Our aim in this review was to provide a detailed overview of abiotic stress responses mediated by ethylene and JAs and their impact on secondary metabolites.

A clue to the evolutionary history of modern East Asian flora: insights from phylogeography and diterpenoid alkaloid distribution pattern of the Spiraea japonica complex

Each subkingdom of East Asian flora (EAF) has a unique evolutionary history, but which has rarely been described based on phylogeographic studies of EAF species. The Spiraea japonica L. complex, which is widespread in East Asia (EA), has received considerable attention because of the presence of diterpenoid alkaloids (DAs). It provides a proxy for understanding the genetic diversity and DA distribution patterns of species under various environmental conditions associated with the geological background in EA. In the present study, the plastome and chloroplast/nuclear DNA of 71 populations belonging to the S. japonica complex and its congeners were sequenced, combined with DA identification, environmental analyses, and ecological niche modelling, to investigate their phylogenetic relationships, genetic and DAs distribution patterns, biogeography, and demographic dynamics. An "ampliative" S. japonica complex was put forward, comprising all species of Sect. Calospira Ser. Japonicae, of which three evolutionary units carrying their respective unique types of DAs were identified and associated with the regionalization of EAF (referring to the Hengduan Mountains, central China, and east China). Moreover, a transition belt in central China with its biogeographic significance was revealed by genetic and DA distribution patterns from the perspective of ecological adaptation. The origin and onset differentiation of the "ampliative" S. japonica complex was estimated in the early Miocene (22.01/19.44 Ma). The formation of Japanese populations (6.75 Ma) was facilitated by the land bridge, which subsequently had a fairly stable demographic history. The populations in east China have undergone a founder effect after the Last Glacial Maximum, which may have been promoted by the expansion potential of polyploidization. Overall, the in-situ origin and diversification of the "ampliative" S. japonica complex since the early Miocene is a vertical section of the formation and development of modern EAF and was shaped by the geological history of each subkingdom.