Synthesis Of Secondary Metabolites Research Articles

Endophyte-mediated enhancement of salt resistance in Arachis hypogaea L. by regulation of osmotic stress and plant defense-related genes

IntroductionSoil salinization poses a significant environmental challenge affecting plant growth and agricultural sustainability. This study explores the potential of salt-tolerant endophytes to mitigate the adverse effects of soil salinization, emphasizing their impact on the development and resistance of Arachis hypogaea L. (peanuts).MethodsThe diversity of culturable plant endophytic bacteria associated with Miscanthus lutarioriparius was investigated. The study focused on the effects of Bacillus tequilensis, Staphylococcus epidermidis, and Bacillus siamensis on the development and germination of A. hypogaea seeds in pots subjected to high NaCl concentrations (200 mM L−1).ResultsUnder elevated NaCl concentrations, the inoculation of endophytes significantly (p < 0.05) enhanced seedling germination and increased the activities of enzymes such as Superoxide dismutase, catalase, and polyphenol oxidase, while reducing malondialdehyde and peroxidase levels. Additionally, endophyte inoculation resulted in increased root surface area, plant height, biomass contents, and leaf surface area of peanuts under NaCl stress. Transcriptome data revealed an augmented defense and resistance response induced by the applied endophyte (B. tequilensis, S. epidermidis, and B. siamensis) strain, including upregulation of abiotic stress related mechanisms such as fat metabolism, hormones, and glycosyl inositol phosphorylceramide (Na+ receptor). Na+ receptor under salt stress gate Ca2+ influx channels in plants. Notably, the synthesis of secondary metabolites, especially genes related to terpene and phenylpropanoid pathways, was highly regulated.ConclusionThe inoculated endophytes played a possible role in enhancing salt tolerance in peanuts. Future investigations should explore protein–protein interactions between plants and endophytes to unravel the mechanisms underlying endophyte-mediated salt resistance in plants.

Management of Secondary Metabolite Synthesis and Biomass in Basil (Ocimum basilicum L.) Microgreens Using Different Continuous-Spectrum LED Lights.

Different LED light spectra (LS) are absorbed by different plant photoreceptors and can control biomass and plant secondary metabolite synthesis. In this study, the effects of continuous-spectrum LED lights (red, blue, white, red + blue, and 12 h blue + 12 h red) on the production value, antioxidant compounds, and biomass of basil (Ocimum basilicum L.) microgreens (Red Rubin, Violeto, and Kapoor cultivars and the Ablagh genotype) were investigated. The results showed significant effects of LS on cultivar (Cv) and the interaction of LS and Cv on the studied traits. The highest quantitys of chlorophyll a, total chlorophyll, and nitrate were obtained in Violeto under blue lighting. Red lighting enhanced starch synthesis in Red Rubin and flavonoids in the Violeto Cv. The highest biomass (4.54 kg m-2) was observed in the Ablagh genotype and the highest carbohydrate synthesis in Violeto Cv in the red + blue treatment. The highest anthocyanin content (26.33 mg 100 g-1 FW) was observed for Red Rubin Cv under 12 h blue + 12 h red light. The greatest antioxidant capacity (83.57% inhibition), the highest levels of phenolic compounds (2027.25 mg GA 100 g-1 FW), vitamin C (405.76 mg 100 g-1 FW), proline, antioxidant potential composite index (APCI), and the greatest production values were obtained for the Ablagh genotype under blue lighting. Taken together, the experiment findings indicate that growing the Ablagh genotype under continuous blue lighting can increase the antioxidant capacity, phenolic compounds, and vitamin C and that this LED light spectrum can be used as a practical method to produce basil microgreens with high nutritional health value.

Plant growth promoters boost the photosynthesis related mechanisms and secondary metabolism of late-sown wheat under contrasting saline regimes

There is an imminent risk of higher crop failures owing to weather vagaries for agriculture-based livelihood systems, which are already fragile due to several challenges. The most important challenge is the encounter of crops against multiple environmental stresses under natural field conditions, the combination of these stresses poses complex effects on plant physiological and metabolic activities. To date, the combined effects of salt stress (SS) and late-sown (LS) on physiological and biochemical attributes have not been studied on wheat. A two-year field study was designed to evaluate the effect of plant growth promoters (PGRPs) to alleviate the individual SS, LS and combinations on wheat. The experiment was conducted for three factors, a) late sown and timely sown, b) saline and non-saline conditions and c) PGRPs treatments (thiourea (TU @ 1000 mg L−1), salicylic acid (SA @ 100 mg L−1), hydrogen peroxide (H2O2 @ 100 µM), water spray (H2O) and control). Data revealed that under stress conditions, especially under SS+LS stress plants increased the synthesis of secondary metabolites, enhanced heat dissipation, and showed strict control over the stomatal regulation and gas exchange attributes, all these mechanisms were tweaked to deal with all the stresses. In addition, SS+LS stress followed by SS and LS stress severely reduced the flag leaf area (FLA), chlorophyll pigment contents and chlorophyll fluorescence and carboxylation capacity. However, foliar treatments of PGRPs TU, followed by SA, H2O2, H2O and control improved the chlorophyll fluorescence, pigments contents, gas exchange indicators, and relative water content (RWC). Moreover, PGRPs application improved the FLA, pigment biosynthesis and carboxylation capacity that improved the synthesis of metabolites such as anthocyanin, niacin, flavonoids, phenolics, alkaloids, saponin and riboflavin, which acted as defensive compounds to preserve the photosynthetic capacity irrespective of stress treatments.

Transcriptome-wide identification of ARF gene family in medicinal plant Polygonatum kingianum and expression analysis ofPkARF members in different tissues.

Polygonatum kingianum holds significant importance in Traditional Chinese Medicine due to its medicinal properties, characterized by its diverse chemical constituents including polysaccharides, terpenoids, flavonoids, phenols, and phenylpropanoids. The Auxin Response Factor (ARF) is a pivotal transcription factor known for its regulatory role in both primary and secondary metabolite synthesis. However, our understanding of the ARF gene family in P. kingianum remains limited. We employed RNA-Seq to sequence three distinct tissues (leaf, root, and stem) of P. kingianum. The analysis revealed a total of 31,558 differentially expressed genes (DEGs), with 43 species of transcription factors annotated among them. Analyses via gene ontology and the Kyoto Encyclopedia of Genes and Genomes demonstrated that these DEGs were predominantly enriched in metabolic pathways and secondary metabolite biosynthesis. The proposed temporal expression analysis categorized the DEGs into nine clusters, suggesting the same expression trends that may be coordinated in multiple biological processes across the three tissues. Additionally, we conducted screening and expression pattern analysis of the ARF gene family, identifying 12 significantly expressed PkARF genes in P. kingianum roots. This discovery lays the groundwork for investigations into the role of PkARF genes in root growth, development, and secondary metabolism regulation. The obtained data and insights serve as a focal point for further research studies, centred on genetic manipulation of growth and secondary metabolism in P. kingianum. Furthermore, these findings contribute to the understanding of functional genomics in P. kingianum, offering valuable genetic resources.

Characterization of Bacillus velezensis TJS119 and its biocontrol potential against insect pathogens.

The white-spotted flower chafer (Protaetia brevitarsis seulensis), which is widely distributed in Asian countries, is traditionally used in oriental medicine. However, its larvae are prone to severe damage by green muscardine disease (caused by Metarhizium anisopliae) during breeding. The aim of this study was to characterize Bacillus velezensis TJS119, which has been isolated from freshwater, and investigate its potential as a biocontrol agent against M. anisopliae in insects. TJS119 was obtained from freshwater samples in the Republic of Korea and was classified as B. velezensis. We evaluated its in vitro antifungal effect, sequenced the bacterial whole genome, mined genes responsible for the synthesis of secondary metabolites, performed secondary metabolite analysis Ultra performance liquid chromatography-mass spectrometry (UPLC-MS/MS), and conducted bioassays for determining green muscardine disease control ability. Bacillus velezensis TJS119 inhibited the mycelial growth of M. anisopliae in vitro. The size of the B. velezensis TJS119 genome was estimated to be 3,890,913 bp with a GC content of 46.67% and 3,750 coding sequences. Biosynthetic gene clusters for secondary metabolites with antifungal activity were identified in the genome. Lipopeptides, including fengycin secreted by TJS119 exhibit antifungal activity. Application of TJS119 for the biocontrol against green muscardine disease increased the viability of white-spotted flower chafer by 94.7% compared to the control. These results indicate that B. velezensis TJS119 is a potential biocontrol agent for insect pathogens.

Effect of the Oligosaccharid Fraction of Fusarium oxysporum f. sp. vasinfectum on the Activity of Phenolic Metabolism Enzymes in Cotton Leaves

The synthesis of secondary metabolites, notably phenolic compounds, is part of the plant's defense reactions. The enzymes of phenolic metabolism can constitute a parameter of measurement of the defense of the plants. The aim of this work is to evaluate the activity of phenolic metabolism enzymes and an antioxidant enzyme after treatment of cotton plants with a fungal elicitor. Cotton plants obtained from the cultivar Y764AG3 were treated with the oligosaccharide fraction (FOS) of Fusarium oxysporum f. sp. Vasinfectum (FOV). The extraction of the enzymes is carried out cold by grinding the leaves in extraction buffer in the presence of PVP (0.5 %) and 0.1 M sodium phosphate buffer. The supernatant obtained after centrifugation of the filtrate was purified with Dowex-2 in order to obtain the purified enzymatic fraction. This fraction was used for the determination of enzyme activity by reading the absorbances. The results showed that the activity of ammonia-lyase activity was higher in the treated plants than in the control. This reflects an increase in the biosynthesis of phenolic compounds in the treated plants. On the other hand, oxidoreductase activity was higher in control plants than in treated plants. This indicates a decrease in the degradation of phenolic compounds in the treated plants. This study revealed the existence of an active phenolic metabolism in the FOS-treated plants. Thus defence mechanisms are activated in plants treated with the oligosaccharide fraction of Fusarium oxysporum f. sp. Vasinfectum.

Unravelling the Function of the Sesquiterpene Cyclase STC3 in the Lifecycle of Botrytis cinerea.

The genome sequencing of Botrytis cinerea supplies a general overview of the map of genes involved in secondary metabolite synthesis. B. cinerea genomic data reveals that this phytopathogenic fungus has seven sesquiterpene cyclase (Bcstc) genes that encode proteins involved in the farnesyl diphosphate cyclization. Three sesquiterpene cyclases (BcStc1, BcStc5 and BcStc7) are characterized, related to the biosynthesis of botrydial, abscisic acid and (+)-4-epi-eremophilenol, respectively. However, the role of the other four sesquiterpene cyclases (BcStc2, BcStc3, BcStc4 and BcStc6) remains unknown. BcStc3 is a well-conserved protein with homologues in many fungal species, and here, we undertake its functional characterization in the lifecycle of the fungus. A null mutant ΔBcstc3 and an overexpressed-Bcstc3 transformant (OvBcstc3) are generated, and both strains show the deregulation of those other sesquiterpene cyclase-encoding genes (Bcstc1, Bcstc5 and Bcstc7). These results suggest a co-regulation of the expression of the sesquiterpene cyclase gene family in B. cinerea. The phenotypic characterization of both transformants reveals that BcStc3 is involved in oxidative stress tolerance, the production of reactive oxygen species and virulence. The metabolomic analysis allows the isolation of characteristic polyketides and eremophilenols from the secondary metabolism of B. cinerea, although no sesquiterpenes different from those already described are identified.

Exogenous curcumin mitigates As stress in spinach plants: A biochemical and metabolomics investigation

The spinach (S. oleracea L.) was used as a model plant to investigate As toxicity on physio-biochemical processes, exploring the potential mitigation effect of curcumin (Cur) applied exogenously at three concentrations (1, 10, and 20 μM Cur). The employment of Cur significantly mitigated As-induced stress in spinach photosynthetic performance (Fv/Fm, Fo/Fm, and Fv/Fo). Moreover, the co-incubation of Cur with As improved physiological processes mainly associated with plant water systems affected by As stress by recovering the leaf's relative water content (RWC) and osmotic potential (ψπ) nearly to the control level and increasing the transpiration rate (E; 39–59%), stomatal conductivity (gs; 86–116%), and carbon assimilation rate (A; 84–121%) compared to As stressed plants. The beneficial effect of Cur in coping with As-induced stress was also assessed at the plant's oxidative level by reducing oxidative stress biomarkers (H2O2 and MDA) and increasing non-enzymatic antioxidant capacity.Untargeted metabolomics analysis was adopted to investigate the main processes affected by As and Cur application. A multifactorial ANOVA discrimination model (AMOPLS-DA) and canonical correlation analysis (rCCA) were employed to identify relevant metabolic changes and biomarkers associated with Cur and As treatments. The results highlighted that Cur significantly determined the accumulation of glucosinolates, phenolic compounds, and an increase in glutathione redox cycle activities, suggesting an overall elicitation of plant secondary metabolisms. Specifically, the correlation analysis reported a strong and positive correlation between (+)-dihydrokaempferol, L-phenylalanine (precursor of phenolic compounds), and serotonin-related metabolites with antioxidant activities (ABTS and DPPH), suggesting the involvement of Cur application in promoting a cross-talk between ROS signaling and phytohormones, especially melatonin and serotonin, working coordinately to alleviate As-induced oxidative stress. The modulation of plant metabolism was also observed at the level of amino acids, fatty acids, and secondary metabolites synthesis, including N-containing compounds, terpenes, and phenylpropanoids to cooperate with As-induced stress response.

Aspergillus clavatonanicus HSF015 possesses the talent in producing bioactive secondary metabolites

Mangrove-associated fungi are excellent sources of bioactive natural products. To explore the value of producing bioactive secondary, the genome and transcriptome of mangrove-associated fungus named A. clavatonanicus HSF015 are sequenced for the first time. According to the genome (8737 function gene), A. clavatonanicus HSF015 with 58.05 % genes expressing shows high performance in metabolism and secondary metabolism. Forty secondary metabolite biosynthesis gene clusters are successfully annotated from 13 contigs in the genome. Thereinto, ten biosynthesis gene clusters can synthesize 17 known compounds with various activities and application values. The remaining 30 gene clusters are unknown secondary metabolite synthesis gene clusters, which are worth exploring. In addition, three known compounds with antioxidant and antibacterial activities were isolated from the broth of A. clavatonanicus HSF015. Hence, A. clavatonanicus HSF015 with the great talent in producing bioactive secondary metabolites is worth further study.

Strategies, Achievements, and Potential Challenges of Plant and Microbial Chassis in the Biosynthesis of Plant Secondary Metabolites.

Diverse secondary metabolites in plants, with their rich biological activities, have long been important sources for human medicine, food additives, pesticides, etc. However, the large-scale cultivation of host plants consumes land resources and is susceptible to pest and disease problems. Additionally, the multi-step and demanding nature of chemical synthesis adds to production costs, limiting their widespread application. In vitro cultivation and the metabolic engineering of plants have significantly enhanced the synthesis of secondary metabolites with successful industrial production cases. As synthetic biology advances, more research is focusing on heterologous synthesis using microorganisms. This review provides a comprehensive comparison between these two chassis, evaluating their performance in the synthesis of various types of secondary metabolites from the perspectives of yield and strategies. It also discusses the challenges they face and offers insights into future efforts and directions.

Characterization and Mechanism Analysis of Sugar Transporter Protein Obtained from Monascus pilosus

Sugar transporter protein family is very common among different organisms in nature and plays a key role in the transportation, absorption, and synthesis of secondary metabolites. To investigate the functional characteristics of sugar transporter proteins in Monascus pilosus, cDNA sequence of sugar transporter protein gene MpST collected from M. pilosus CICC 5045 was cloned in this research. Furthermore, bioinformatics methods and molecular docking techniques were applied to analyze MpST protein. The obtained results revealed that the coding region of MpST was 1677 bp in length, which coded 558 amino acids, and it was a stable protein. Phylogenetic tree analysis found a close relationship between MpST and two other proteins from M. purpureus (BDD61243.1 and TQB74099.1). Bioinformatics analyses indicated that this protein is a hydrophilic protein with 11 transmembrane domains and its functional domains were mainly consisted of the conserved domains of major facilitator superfamily (MFS) and sugar transporter proteins, suggesting that this protein belonged to MFS transporter protein family. Molecular docking results suggested that the receptor protein could spontaneously bind with high affinity to small molecular ligands such as galactose, raffinose, glucose, xylose, and maltose. From the above analyses, it was predicted that this protein might have good transport function for the above five sugars. This study lays the foundation for further in-depth research on the functions and applications of this protein.

Fermentation of soybean residue by A. auricula: Mechanisms and uses

The biochemical conversion mechanism of soybean residue by liquid-state fermentation with Auricularia auricula mycelium (AAM) was elucidated through the determination of enzymes and basic nutrients during fermentation as well as the metabolites analysis. The metabolomics analysis was conducted on the differential metabolites of A. auricula using LC-MS/MS and found a total of 351 differential metabolites, including organic acids, sugars, amino acids, phenols etc.; most of which were organic acids, and glycosides. All the differentially expressed compounds were analyzed by KEGG metabolic pathway enrichment. There were 30 metabolic pathways related to the metabolic mechanism of soybean residue conversion; among them, fatty acid synthesis, sugar metabolism, carbon synthesis, and the synthesis of various secondary metabolites were the main metabolic pathways. During the whole fermentation process, the content of flavonoids decreased gradually and its content was 0.001 mg/g after 15 days of fermentation. This indicated that AAM successfully fermented and transformed the soybean dregs into nutritionally rich products. As it was rich in high protein, 3D printing technology was utilized to develop a AAM protein-based cream substitute. The ink exhibited excellent 3D printability owing to its solid viscoelastic behavior. The ink rheology was controlled by XG concentrations, and 3D printed AAM protein emulsion with 2.0% XG showed printing stability. We also produced AAM protein-rich food products using traditional culinary processing techniques. It provided a theoretical basis for realizing the comprehensive utilization of soybean residue and can be used as a new protein source in the food industry with good application prospects.

Transcriptomics combined with physiology reveals the effect of different light qualities on the development of Fritillaria cirrhosa in the Qinghai Tibet Plateau

Fritillaria cirrhosa, a high-altitude plant susceptible to environmental conditions, commonly grows beneath bushes and is categorized as shade-tolerant. The development and secondary metabolite synthesis of F. cirrhosa are significantly influenced by light quality. This study investigated the physiological responses and molecular mechanisms of F. cirrhosa to different light qualities using colored agricultural film treatments. The results demonstrated that the number of sprout tumbles in F. cirrhosa was significantly reduced by the different colored film treatments. The quality of the fruits exhibited a notable improvement under the blue film (BF) treatment compared to the other groups (P < 0.05). The guanosine content showed a substantial increase of 440.55% under the BF treatment relative to the white film (WF), and the uracil content significantly increased by 171.27% in BF and by 296.38% in the green film (GF). Leaf thickness was considerably higher under the GF treatment than under the other conditions. F. cirrhosa demonstrated enhanced photosynthesis when exposed to BF and GF (P < 0.05). The transcriptome results indicated 75 differentially expressed genes (DEGs) involved in photosynthesis-related pathways that regulated photosynthetic utilization efficiency by encoding photosynthetic antenna proteins (Lhca and Lhcb), photosynthetic electron transporters (PsbE, PsbP, and PetA), and carbon fixation enzymes (PPC, PPDK, and rbcL). Most these genes were upregulated in BF and GF, improving the light energy conversion efficiency, photosynthetic electron transport rate, and CO2 assimilation ability in F. cirrhosa. Notably, 44 DEGs involved in flavonoid metabolic pathways (PAL, HCT, 4CL, CHS, CHI, and ANS) showed higher expression levels in WF and yellow film (YF), differing in the regulation of the photosynthetic pathway. This suggested that F. cirrhosa can utilize nutrients produced by photosynthesis more efficiently under BF and GF, and does not require excessive amounts of flavonoids for maintaining cell homeostasis. These results offer valuable insights into the transcriptional changes and molecular processes occurring in F. cirrhosa in response to different light qualities and provide a basis for research on the mechanisms of photo regulation, cultivation, and ecological adaptation in F. cirrhosa.

The transcription factor STE12 influences growth on several carbon sources and production of dehydroacetic acid (DHAA) in Trichoderma reesei

The filamentous ascomycete Trichoderma reesei, known for its prolific cellulolytic enzyme production, recently also gained attention for its secondary metabolite synthesis. Both processes are intricately influenced by environmental factors like carbon source availability and light exposure. Here, we explore the role of the transcription factor STE12 in regulating metabolic pathways in T. reesei in terms of gene regulation, carbon source utilization and biosynthesis of secondary metabolites. We show that STE12 is involved in regulating cellulase gene expression and growth on carbon sources associated with iron homeostasis. STE12 impacts gene regulation in a light dependent manner on cellulose with modulation of several CAZyme encoding genes as well as genes involved in secondary metabolism. STE12 selectively influences the biosynthesis of the sorbicillinoid trichodimerol, while not affecting the biosynthesis of bisorbibutenolide, which was recently shown to be regulated by the MAPkinase pathway upstream of STE12 in the signaling cascade. We further report on the biosynthesis of dehydroacetic acid (DHAA) in T. reesei, a compound known for its antimicrobial properties, which is subject to regulation by STE12. We conclude, that STE12 exerts functions beyond development and hence contributes to balance the energy distribution between substrate consumption, reproduction and defense.

Study on the regulatory mechanism of vinegar grains metabolism via different vinegar starters

The application of biofortification technology in regulating the microbial community of Sichuan bran vinegar (SBV) to enhance its quality has garnered significant attention recently. Here, we utilized Cuqu fortified (JQ) by synthetic microbiota composed of two different strains to enhance SBV fermentation, while simultaneously revealing community succession and metabolic regulatory mechanisms. Compared to control samples, the fortified vinegar grains (ZJV) community exhibited a 1.60-fold increase in bacterial biomass during major stages. Dominant fungi dynamics in ZJV significantly shifted, with a notable increase in Monascus and Rasamsonia. Upregulation of enzymes involved in starch and cellulose degradation led to increased contents of volatiles, 4-ethylguaiacol (4-EG), and raw starch conversion rate in the fermented ZJV by 1.75 times, 40 times, and 21.92%, respectively. Biofortification boosted interspecies interactions, clustering functional microbes into a module. Functional bacteria served as connectors, enhancing fungal-bacterial communication, optimizing information and energy exchange, reducing primary metabolite accumulation like ethanol, and improving nutrient utilization and metabolic conversion for secondary metabolite synthesis. These findings establish crucial groundwork for the practical application of synthetic microbiota in various engineering applications.

Epigenetic factors of the effect of UV-C and X-ray presowing seeds radiation exposure in Matricaria chamomilla L. genotypes

In a series of experiments using both X-ray and UV-C radiation exposure a parallel study of several pharmacological characteristics of the Matricaria chamomilla L. genotype group was carried out. The data concerning the changes in the productivity of pharmacological raw materials and stimulation of the synthesis of low molecular weight antioxidants as markers of secondary metabolism induction have been published earlier. In this study, the data on the relationship between the stimulation of the synthesis of secondary metabolites under different types of irradiation and the epigenetic changes in the plant organism are presented. It was shown that DNA methylation was switched to the de novo mode in plants of all studied genotypes of M. chamomilla under both types of irradiation. That indicates changes in the epigenetic program of the plant organism. Comparison of the epigenetic pattern between control and irradiated samples, based on the difference in DNA methylation patterns in terms of a statistical indicator, shows that there is no unambiguous relationship between the epigenetic changes and increasing yield of antioxidant synthesis. This is additional evidence of the diversity of metabolic rearrangements and adaptive strategies of the plant organism under radiation exposure even within one species.

Exploring the Biochemical Profiles of Medicinal Plants Cultivated Under Stressful Environmental Conditions

The therapeutic potential of medicinal plants, attributed to diverse bioactive chemicals, is impacted by dynamic metabolic changes under environmental stressors such as salt, drought, and heavy metal exposure. This study aimed to elucidate the biochemical alterations in stressed medicinal plants and their implications for therapeutic qualities. Two groups of plants were compared: one cultivated in optimal conditions, serving as a control, and the other exposed to stressors mimicking real-world scenarios. Biochemical parameters, including total phenolic content, flavonoids, antioxidant activity, and specific secondary metabolites, were assessed using established analytical methods. In a case study involving Aloe vera under elevated soil salinity, a significant decrease in total phenolic content and antioxidant activity was observed. Surprisingly, aloin, an anti-inflammatory bioactive compound, exhibited notable upregulation. Stress-induced biochemical variations in medicinal plants differed significantly from those in ideal conditions, demonstrating adaptive responses, including modulation of secondary metabolite synthesis. While certain stresses led to an overall decrease in secondary metabolites, specific instances showed an overexpression of beneficial chemicals. Exploring drought stress in Lavandula angustifolia (lavender), Vitis vinifera, and Artemisia tridentata, revealed a marked reduction in flavonoids and specific secondary metabolites. The study aimed to establish connections between metabolic alterations and stress-adaptive reactions. The findings contribute to understanding how environmental stress influences the therapeutic efficacy of medicinal plants and shed light on the molecular pathways governing stress-induced changes. In the investigation of heavy metal exposure, Hypericum perforatum, and Coriandrum sativum subjected to cadmium-contaminated soil exhibited an overall decline in secondary metabolites, including reduced hypericin content. Contrarily, hyperforin, linked to antidepressant properties, experienced a significant increase. These results have implications for pharmaceutical applications, sustainable farming practices, and the conservation of medicinal plant biodiversity amidst changing environmental dynamics. The study underscores the intricate relationship between environmental stressors and the biochemical makeup of medicinal plants, emphasizing their resilience and capacity to produce valuable bioactive molecules in challenging conditions. The comparative biochemical analysis of stressed medicinal plants involves assessing various parameters to comprehend how stress influences plant metabolism and bioactive compound production.

Arbuscular Mycorrhizal Fungi-Mediated Modulation of Physiological, Biochemical, and Secondary Metabolite Responses in Hemp (Cannabis sativa L.) under Salt and Drought Stress.

The increasing impact of global climate change has resulted in adversity stresses, like salt and drought, gradually becoming the main factors that limit crop growth. Hemp, which contains numerous medicinal active components and multiple bioactive functions, is widely used in the agricultural, industrial, and medical fields, hence promoting the rapid development of related industries. Arbuscular mycorrhizal fungi (AMF) can establish a symbiotic relationship with 80% of vascular plants. This symbiosis promotes host plant growth, regulates plant physiology and biochemistry, facilitates secondary metabolite synthesis, and enhances resistance to abiotic stresses. However, the effects of salt stress, drought stress, and AMF interaction in hemp are not well understood. In this study, to investigate this, we performed a study where we cultured hemp that was either inoculated or uninoculated with Funneliformis mosseae and determined changes in effective colonization rate, growth, soluble substances, photosynthesis, fluorescence, ions, and secondary metabolites by cultivating hemp under different concentrations of NaCl (0 mM, 100 mM, and 200 mM) and different soil moisture content (45%, 25%, and 15%). The results showed that salt, drought stress, or salt-drought interaction stress all inhibited colonization rate after stress, plant growth, mainly due to ion toxicity and oxidative damage. Inoculation with F. mosseae effectively alleviated plant growth inhibition under 100 mM NaCl salt stress, drought stress, and salt-drought interaction stress conditions. It also improved osmoregulation, photosynthetic properties, fluorescence properties, and ion homeostasis, and promoted the accumulation of secondary metabolites. However, under 200 mM NaCl salt stress conditions, inoculation with F. mosseae negatively affected plant physiology, biochemistry, and secondary metabolite synthesis, although it did alleviate growth inhibition. The results demonstrate that there are different effects of salt-drought interaction stress versus single stress (salt or drought stress) on plant growth physiology. In addition, we provide new insights about the positive effects of AMF on host plants under such stress conditions and the effects of AMF on plants under high salt stress.

Influence of Abiotic and Biotic Elicitors on Organogenesis, Biomass Accumulation, and Production of Key Secondary Metabolites in Asteraceae Plants.

The medicinal plants of the Asteraceae family are a valuable source of bioactive secondary metabolites, including polyphenols, phenolic acids, flavonoids, acetylenes, sesquiterpene lactones, triterpenes, etc. Under stressful conditions, the plants develop these secondary substances to carry out physiological tasks in plant cells. Secondary Asteraceae metabolites that are of the greatest interest to consumers are artemisinin (an anti-malarial drug from Artemisia annua L.-sweet wormwood), steviol glycosides (an intense sweetener from Stevia rebaudiana Bert.-stevia), caffeic acid derivatives (with a broad spectrum of biological activities synthesized from Echinacea purpurea (L.) Moench-echinacea and Cichorium intybus L.-chicory), helenalin and dihydrohelenalin (anti-inflammatory drug from Arnica montana L.-mountain arnica), parthenolide ("medieval aspirin" from Tanacetum parthenium (L.) Sch.Bip.-feverfew), and silymarin (liver-protective medicine from Silybum marianum (L.) Gaertn.-milk thistle). The necessity to enhance secondary metabolite synthesis has arisen due to the widespread use of these metabolites in numerous industrial sectors. Elicitation is an effective strategy to enhance the production of secondary metabolites in in vitro cultures. Suitable technological platforms for the production of phytochemicals are cell suspension, shoots, and hairy root cultures. Numerous reports describe an enhanced accumulation of desired metabolites after the application of various abiotic and biotic elicitors. Elicitors induce transcriptional changes in biosynthetic genes, leading to the metabolic reprogramming of secondary metabolism and clarifying the mechanism of the synthesis of bioactive compounds. This review summarizes biotechnological investigations concerning the biosynthesis of medicinally essential metabolites in plants of the Asteraceae family after various elicitor treatments.

Physiological and molecular mechanisms of ZnO quantum dots mitigating cadmium stress in Salvia miltiorrhiza

This study delved into the physiological and molecular mechanisms underlying the mitigation of cadmium (Cd) stress in the model medicinal plant Salvia miltiorrhiza through the application of ZnO quantum dots (ZnO QDs, 3.84 nm). A pot experiment was conducted, wherein S. miltiorrhiza was subjected to Cd stress for six weeks with foliar application of 100 mg/L ZnO QDs. Physiological analyses demonstrated that compared to Cd stress alone, ZnO QDs improved biomass, reduced Cd accumulation, increased the content of photosynthetic pigments (chlorophyll and carotenoids), and enhanced the levels of essential nutrient elements (Ca, Mn, and Cu) under Cd stress. Furthermore, ZnO QDs significantly lowered Cd-induced reactive oxygen species (ROS) content, including H2O2, O2−, and MDA, while enhancing the activity of antioxidant enzymes (SOD, POD, APX, and GSH-PX). Additionally, ZnO QDs promoted the biosynthesis of primary and secondary metabolites, such as total protein, soluble sugars, terpenoids, and phenols, thereby mitigating Cd stress in S. miltiorrhiza. At the molecular level, ZnO QDs were found to activate the expression of stress signal transduction-related genes, subsequently regulating the expression of downstream target genes associated with metal transport, cell wall synthesis, and secondary metabolite synthesis via transcription factors. This activation mechanism contributed to enhancing Cd tolerance in S. miltiorrhiza. In summary, these findings shed light on the mechanisms underlying the mitigation of Cd stress by ZnO QDs, offering a potential nanomaterial-based strategy for enhancing Cd tolerance in medicinal plants.