Secondary Metabolites Research Articles

Thermochemical energy storage with the solid-gas reaction of SrCO3 improved with CaCO3

Abstract In the context of thermochemical energy storage (TCES) for concentrating solar power (CSP) applications, metal carbonates’ reversible calcination and carbonation are gaining prominence, particularly in the SrCO3/SrO system. This system is notable for its high theoretical energy density of 10.61 GJ/m³ and operational temperatures up to 1,200 °C. However, like the CaCO3/CaO system, SrO experiences a significant drop in reactivity during cycling due to sintering and agglomeration of particles. In this work is proposed that the conversion effective will be improved by mixing the strontium carbonate with calcium carbonate. The best mix found was 80/20 SrCO3/CaCO3 with the operating parameters of calcination-carbonation temperatures of 1,200 °C and 900 °C, respectively. This reaction has a notably better stable conversion rate than pure strontium carbonate. The study was carried out using thermogravimetry analysis. The mixture was subjected to 9 cycles, and for the ninth cycle, there was an effective conversion of 33.14 %, which, compared to pure SrCO3, was 2.33 %; that was improved noticeably during the carbonation process. There was an increase in the percentage effective conversion of 30.81 %. Volumetric energy density was reduced from 6.93 to 2.81 GJ/m3 in the first and after nine cycles. The XRD analysis of the unprocessed mixture after 4 and 9 cycles showed no formation of new or secondary compounds, only the expected compounds: SrO, SrCO3, CaO, and CaCO3. This important change is explained during the carbonation looping because the CaO remains encapsulated in the SrCO3 and does not react completely at 900 °C. As a hypothesis, this encapsulation delays the sintering of the SrCO3. Using a T carb = 850 °C promotes the carbonation of CaO. By promoting CaO to react, the CaO encapsulated is released rapidly, and the material was sintering faster than the T carb = 900 °C. Comparing the seventh cycle at a T carb = 900 and 850 °C, it is observed that the effective conversion decreases from 0.4431 to 0.4202 and, in the same proportion, the volumetric energy density.

Unlocking the Immunomodulatory Potential of Rosmarinic Acid Isolated from Punica granatum L. using Bioactivity-Guided Approach: In Silico, In Vitro, and In Vivo Approaches.

Punica granatum L. is well-known for its multifaceted therapeutic potential, including anti-inflammatory and immunomodulatory activities. This study aimed to characterize an immunomodulatory compound isolated from Punica granatum L. using a bioactivity-guided approach. Chromatographic techniques were adopted for isolation and purification of secondary metabolites. In silico, in vitro, and in vivo methods were performed to characterize the therapeutic potential of the isolated compound. Using preparative thin-layer chromatography, rosmarinic acid was isolated from F4 (column chromatography product obtained from a butanolic fraction of the extract). The impact of rosmarinic acid was assessed in rats using the neutrophil adhesion test, DTH response, and phagocytic index. In immunized rats, rosmarinic acid demonstrated significant immunomodulatory potential. Computational experiments, like molecular docking and molecular dynamics, were also conducted against two targeted receptors, Cereblon (PDB ID: 8AOQ) and human CD22 (PDB ID: 5VKM). Computational studies suggested that an increase in phagocytic index by rosmarinic acid could be attributed to inhibiting Cereblon and CD22. Pharmacokinetics and toxicity prediction also suggested the drug-likeness of rosmarinic acid. Rosmarinic acid is a potential candidate, but extensive research needs to be done to translate this molecule from bench to bedside.

Characterization of two glutathione S‐transferase genes involved in clothianidin resistance in Bradysia odoriphaga

AbstractBACKGROUNDGlutathione S‐transferase (GST) is a key phase II detoxification enzyme involved in xenobiotics metabolism, and plays a pivotal role in the evolution of resistance to various types of insecticides. However, the specific functions of GST genes in clothianidin resistance remain obscure in Bradysia odoriphaga.RESULTSHere, a specific GST inhibitor, diethyl maleate (DEM), significantly increased the mortality of Bradysia odoriphaga larvae following exposure to clothianidin, and the activity of GST enzyme in clothianidin‐resistant (CL‐R) strain of Bradysia odoriphaga was markedly greater than that in the SS strain. Two sigma BoGSTs (BoGSTs1 and BoGSTs2) were markedly overexpressed in the CL‐R strain and exhibited a higher abundance in the Malpighian tubules or midgut. Exposure to clothianidin resulted in a significant increased expression of BoGSTs1 and BoGSTs2. The knockdown of BoGSTs1 and BoGSTs2 increased sensitivity of larvae to clothianidin in the resistant strain. Furthermore, overexpression of BoGSTs1 and BoGSTs2 led to a significant increase in Escherichia coli cells tolerance to clothianidin. In vitro metabolic assays indicate that these two GSTs cannot directly metabolize clothianidin and its secondary metabolite desmethyl‐clothianidin. Disk diffusion assays and fluorescence competitive binding assays indicated that BoGSTs1 and BoGSTs2 play a critical role in clothianidin resistance by antioxidant activity and non‐catalytic binding activity. The docking results showed that BoGSTs1 and BoGSTs2 have strong binding affinity toward clothianidin.CONCLUSIONCollectively, these findings pinpoint the potential role of BoGSTs1 and BoGSTs2 in conferring insecticide resistance in Bradysia odoriphaga and contribute to our understanding of the underlying mechanisms of insecticide resistance. © 2024 Society of Chemical Industry.

Synthesis, characterization and photo catalytic activity of silver nano particle derived from Arachis hypogaea L. seed peel extracts

Abstract The study focuses on the green synthesis of silver nanoparticles (AgNPs) using Arachis hypogaea L. seed peel extract (AHSPE) and evaluates their photocatalytic activity against Rhodamine B and Congo Red dyes. The synthesis involved reducing aqueous silver metal ions with AHSPE, characterized by various techniques including UV–visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and FT-Raman spectroscopy. UV–visible spectroscopy indicated characteristic absorption peaks at 428 and 439 nm, confirming the formation of AgNPs. XRD analysis revealed an average particle size of 4.77–5.6 nm. FT-IR spectra identified biomolecules such as amines, peptides, amides, lactones, and polyphenols in the extract, acting as reducing and capping agents, thereby stabilizing the AgNPs. SEM analysis showed pristine silver nanoparticles with diameters ranging from 1 to 10 µm. The biosynthesized AgNPs demonstrated strong photocatalytic activity in degrading Rhodamine B and Congo Red dyes. This method did not use any synthetic reagents, making it an environmentally safe and cost-effective alternative for synthesizing silver nanoparticles. The process aligns with green chemistry principles, offering potential applications in photocatalysis and environmental cleanup. The study underscores the importance of biosynthesized nanoparticles due to their unique biological properties and the role of plant secondary metabolites in facilitating green synthesis.

Decoding the Impact of a Bacterial Strain of Micrococcus luteus on Arabidopsis Growth and Stress Tolerance

Microbes produce various bioactive metabolites that can influence plant growth and stress tolerance. In this study, a plant growth-promoting rhizobacterium (PGPR), strain S14, was identified as Micrococcus luteus (designated as MlS14) using de novo whole-genome assembly. The MlS14 genome revealed major gene clusters for the synthesis of indole-3-acetic acid (IAA), terpenoids, and carotenoids. MlS14 produced significant amounts of IAA, and its volatile organic compounds (VOCs), specifically terpenoids, exhibited antifungal activity, suppressing the growth of pathogenic fungi. The presence of yellow pigment in the bacterial colony indicated carotenoid production. Treatment with MlS14 activated the expression of β-glucuronidase (GUS) driven by a promoter containing auxin-responsive elements. The application of MlS14 reshaped the root architecture of Arabidopsis seedlings, causing shorter primary roots, increased lateral root growth, and longer, denser root hairs; these characteristics are typically controlled by elevated exogenous IAA levels. MlS14 positively regulated seedling growth by enhancing photosynthesis, activating antioxidant enzymes, and promoting the production of secondary metabolites with reactive oxygen species (ROS) scavenging activity. Pretreatment with MlS14 reduced H2O2 and malondialdehyde (MDA) levels in seedlings under drought and heat stress, resulting in greater fresh weight during the post-stress period. Additionally, exposure to MlS14 stabilized chlorophyll content and growth rate in seedlings under salt stress. MlS14 transcriptionally upregulated genes involved in antioxidant defense and photosynthesis. Furthermore, genes linked to various hormone signaling pathways, such as abscisic acid (ABA), auxin, jasmonic acid (JA), and salicylic acid (SA), displayed increased expression levels, with those involved in ABA synthesis, using carotenoids as precursors, being the most highly induced. Furthermore, MlS14 treatment increased the expression of several transcription factors associated with stress responses, with DREB2A showing the highest level of induction. In conclusion, MlS14 played significant roles in promoting plant growth and stress tolerance. Metabolites such as IAA and carotenoids may function as positive regulators of plant metabolism and hormone signaling pathways essential for growth and adaptation to abiotic stress.

Priming with multiwalled carbon nanotubes improved biomass accumulation, biological activity and metabolism of four horticultural plants during the sprouting stage

AbstractBACKGROUNDIt is imperative to enhance the quality of sprouts since they are a rich source of various primary and secondary metabolites. The objective of this work was to examine how multiwalled carbon nanotubes (MWCNTs) priming at various concentrations affected the nutritional qualities of four horticultural plants (T. foenum‐graecum, L. grandiflorum, L. sativum and A. graveolens) and their sprouting processes.RESULTSAmong the four applied concentrations (10–60 mgL−1), MWCNTs at 10 and 40 mg L⁻¹ induced the highest biomass accumulation in L. grandiflorum and T. foenum‐graecum, respectively, while 60 mg L⁻¹ was most effective for L. sativum and A. graveolent. MWCNTs induced growth by enhancing photosynthesis, as shown by increased chlorophyll content and rubisco activity, which rose by 27%, 17%, 23% and 12% in T. foenum‐graecum, L. grandiflorum, L. sativum, and A. graveolens, respectively. Enhanced photosynthesis by MWCNTs improved sugar metabolism as indicated by increased activity of sugar metabolic enzymes such as amylase, starch synthase and invertase. This also supplied the carbon necessary for the production of primary (amino acids, fatty acids and organic acids) and secondary (flavonoids and polyphenols) metabolites. There was consistently higher activity of antioxidant enzymes (catalase and peroxidase). Interestingly, species‐specific reactions to MWCNT priming were observed, where L. sativum sprouts showed the highest antioxidant activity, followed by A. graveolens.CONCLUSIONMWCNT priming improves sprout growth and nutritional quality by boosting metabolic processes and antioxidant activity, presenting a promising approach for sustainable agriculture. © 2024 Society of Chemical Industry.

The biosynthesis of the odorant 2-methylisoborneol is compartmentalized inside a protein shell

Terpenoids are the largest class of natural products, found across all domains of life. One of the most abundant bacterial terpenoids is the volatile odorant 2-methylisoborneol (2-MIB), partially responsible for the earthy smell of soil and musty taste of contaminated water. Many bacterial 2-MIB biosynthetic gene clusters were thought to encode a conserved transcription factor, named EshA in the model soil bacterium Streptomyces griseus. Here, we revise the function of EshA, now referred to as Sg Enc, and show that it is a Family 2B encapsulin shell protein. Using cryo-electron microscopy, we find that Sg Enc forms an icosahedral protein shell and encapsulates 2-methylisoborneol synthase (2-MIBS) as a cargo protein. Sg Enc contains a cyclic adenosine monophosphate (cAMP) binding domain (CBD)-fold insertion and a unique metal-binding domain, both displayed on the shell exterior. We show that Sg Enc CBDs do not bind cAMP. We find that 2-MIBS cargo loading is mediated by an N-terminal disordered cargo-loading domain and that 2-MIBS activity and Sg Enc shell structure are not modulated by cAMP. Our work redefines the function of EshA and establishes Family 2B encapsulins as cargo-loaded protein nanocompartments involved in secondary metabolite biosynthesis.

Moving beyond species: fungal function in house dust provides novel targets for potential indicators of mold growth in homes

BackgroundIncreased risk of asthma and other respiratory diseases is associated with exposures to microbial communities growing in damp and moldy indoor environments. The exact causal mechanisms remain unknown, and occupant health effects have not been consistently associated with any species-based mold measurement methods. We need new quantitative methods to identify homes with potentially harmful fungal growth that are not dependent upon species. The goal of this study was to identify genes consistently associated with fungal growth and associated function under damp conditions for use as potential indicators of mold in homes regardless of fungal species present. A de novo metatranscriptomic analysis was performed using house dust from across the US, incubated at 50%, 85%, or 100% equilibrium relative humidity (ERH) for 1 week.ResultsGene expression was a function of moisture (adonis2 p < 0.001), with fungal metabolic activity increasing with an increase in moisture condition (Kruskal–Wallis p = 0.003). Genes associated with fungal growth such as sporulation (n = 264), hyphal growth (n = 62), and secondary metabolism (n = 124) were significantly upregulated at elevated ERH conditions when compared to the low 50% ERH (FDR-adjusted p ≤ 0.001, log2FC ≥ 2), indicating that fungal function is influenced by damp conditions. A total of 67 genes were identified as consistently associated with the elevated 85% or 100% ERH conditions and included fungal developmental regulators and secondary metabolite genes such as brlA (log2FC = 7.39, upregulated at 100% compared to 85%) and stcC (log2FC = 8.78, upregulated at 85% compared to 50%).ConclusionsOur results demonstrate that moisture conditions more strongly influence gene expression of indoor fungal communities compared to species presence. Identifying genes indicative of microbial growth under damp conditions will help develop robust monitoring techniques for indoor microbial exposures and improve understanding of how dampness and mold are linked to disease.-X5AkW-U2mftBzktcaxDSrVideo

Studies on Secondary Metabolites and Biological Activities of Fungus Aspergillus sp. PQJ-1 from Sphagneticola trilobata

Studies on Secondary Metabolites and Biological Activities of Fungus Aspergillus sp. PQJ-1 from Sphagneticola trilobata

Metabolomic profiling and 16 S rRNA metabarcoding of endophytes of two Aloe species revealed diverse metabolites

Aloe species are often used interchangeably for medicinal and cosmeceutical applications, presenting a challenge to the biological efficacy consistency of some herbal preparations. Sustainable production of high-quality commonly used medicinal plants remains a limitation for commercialisation. Thus, this study investigated the potential for plant substitution by examining bacterial endophytes capable of producing similar host plant secondary metabolites. The metabolite profiles and endophytic bacterial communities of endangered Aloe lettyae were compared with those of Aloe longibracteata using nuclear magnetic resonance spectroscopy and 16 S rRNA gene sequencing. Only 15 metabolites were significantly different between A. lettyae and A. longibracteata based on metabolite concentrations. However, both plants’ functionality and potential application remain comparable. Phytohormones, including indole-3-acetate and 5-hydroxyindole-3-acetate, were more concentrated in A. lettyae than A. longibracteata. Metabolites such as tyrosine, allantoin, and myo-inositol, with human health benefits, were annotated in both species. Aloe lettyae harboured a phylogenetically diverse bacteria community compared to A. longibracteata, with a higher richness of bacterial species, indicating a likelihood of diverse metabolic capabilities among the bacteria. Dominant endophytes, including Bacillus, Comamonas, and Pseudomonas, possess enzymes contributing to various metabolic pathways. The enzymes have the potential to impact the synthesis, or breakdown of plant metabolites, consequently influencing the overall metabolic composition of the host plant. Therefore, this study supports the interchangeability of A. lettyae and A. longibracteata due to their ability to produce similar metabolites, and although the Aloe species exhibit phylogenetically diverse endophytic communities, the feasibility of utilizing their endophytes as producers of secondary metabolites remains viable.Graphical abstract

Genome-wide identification and functional analysis of CYP450 genes in eggplant (Solanum melongena L.) with a focus on anthocyanin accumlation

BackgroundIn plants, Cytochrome P450 (CYP450) constitutes the largest family of metabolic enzymes and plays a crucial role in various physiological processes, including plant growth and development. Eggplants are well-known for their peel’s high concentration of anthocyanin compounds that provide significant health benefits to humans. The accumulation of anthocyanins in eggplant peels is an important process during growth and development. Therefore, it is essential to identify the CYP450 genes in eggplant (SmCYPs) and analyze their expression profiles during the period of anthocyanin accumulation in the peel.ResultsA total of 180 SmCYPs were identified in the eggplant genome and classified into eight subfamilies based on phylogenetic analysis. These SmCYPs exhibited highly conserved gene structure (exon/intron) and protein motifs, especially within their respective subgroup. Sixteen pairs of genes with collinearity were identified through gene duplication analysis. Promoter cis-acting element analysis revealed that SmCYPs are involved in various responses, including growth and development, stress responsiveness, and light responsiveness. Transcriptome data analysis revealed that all SmCYPs were expressed in various eggplant tissues, such as roots, stems, leaves, flowers, and fruits; with diverse expression patterns among members. The expression patterns of SmCYPs in eggplant peel also exhibited diversity during different stages of anthocyanin accumulation. qRT-PCR analysis demonstrated similar expression patterns for 15 selected SmCYPs as observed in the transcriptome data. Metabolomics analysis further suggested that SmCYPs are involved in the biosynthesis of secondary metabolites and metabolic pathways related to flavonoid and flavone/flavonol biosynthesis. Notably, three specific SmCYPs (SmCYP73A1/75A/98A1) play a significant role in flavonoid biosynthesis, particularly in anthocyanin synthesis in eggplant.ConclusionGenome-wide identification, phylogenetic analysis, expression profile analysis, and exploration of metabolic pathways related to SmCYPs provide valuable insights into the roles of these genes in anthocyanin accumulation in various tissues and organs, including eggplant peel. The findings from this study lay a foundation for the functional analysis of SmCYPs involvement in anthocyanin accumulation in eggplant peel, providing a molecular basis for breeders to cultivate novel varieties of eggplants with high levels of anthocyanin content.

Short-term organic fertilizer substitution increases sorghum yield by improving soil physicochemical characteristics and regulating microbial community structure

IntroductionChemical fertilizer reduction combined with organic fertilizer (organic fertilizer substitution) has a positive impact on crop productivity and sustainable development. However, the effects of short-term organic fertilizer substitution on microbial community structure and functions of sorghum rhizosphere soil and on sorghum yield remain unclear. Herein, this study investigated the short-term effects of organic fertilizer substitution on sorghum soil physicochemical properties, microbial community structure and enzyme activities using Metagenomic sequencing technology.MethodsThe fertilization treatment included no fertilization (CK), pure chemical fertilizer N (CF), substitution of 25% chemical fertilizer N with organic N (NF25), substitution of 50% chemical fertilizer N with organic N (NF50), substitution of 75% chemical fertilizer N with organic N (NF75), and pure organic fertilizer N (NF100); soil samples were collected and analyzed in the flowering period of sorghum.Results and DiscussionThe results showed that the suitable organic fertilizer substitution rate of sorghum field was 50%, and its yield was the highest among all treatments (9789.9 kg/hm2). Compared with the CF treatment, a medium ratio (50%) of organic fertilizer substitution significantly reduced soil alkalization (by 3.05%), improved soil nutrients, enhanced soil enzyme activities, and increased sorghum yield (P &amp;lt; 0.05). After organic fertilizer substitution treatment, higher protein, fat, and total starch levels accumulated in sorghum grains, and the tannin content of grains decreased. The effect of organic fertilizer substitution on bacterial diversity was greater than that on fungal diversity. Among the dominant bacterial phyla, the medium ratio of organic substitution treatment significantly increased the relative abundances of Proteobacteria (by 3.57%) and Actinomycetes (by 14.94%), and decreased the relative abundances of Acidobacteria (by 5.18%) and Planctomycetes (by 7.76%) compared with no fertilization, while the dominant fungal phyla did not respond significantly to the addition of organic fertilizer. Organic fertilizer substitution also improved soil microbial metabolic pathways, biosynthesis of secondary metabolites, and carbon metabolism. The biomarkers enriched in inorganic fertilizer treatment and organic fertilizer substitution treatments had similar relevant environmental elements but reversed correlation trends. Moreover, soil Alkali-hydrolyzable nitrogen and L-leucine aminopeptidase were important environmental factors influencing the structure of bacterial and fungal communities in sorghum soils, respectively. Soil nutrient levels and microbial communities together explained the variation in annual sorghum yield. The results of this study provide evidence that short-term organic fertilizer substitution increases sorghum yield by improving soil properties and regulating microbial community structure.

Recent advances on the impact of protumorigenic dietary‐derived bacterial metabolites on the intestinal stem cell

AbstractThe links between diet, microbiome, immunity, and colorectal cancer are well established. The metabolite output of the microbiome, which has a large influence over host health and disease, is related to the composition of the diet. These metabolites subsequently impact on immune and intestinal epithelial either directly or indirectly via production of secondary metabolites. Here we summarize the latest findings and briefly discuss their potential for managing disease risk.

The Use of Thyme (Thymus vulgaris) Essential Oil for Controlling Cercospora Leaf Spot (Cercospora beticola) on Sugar Beets (Beta vulgaris)

Decreasing efficacy of fungicides and the withdrawal of further hazardous active ingredients in pesticides from use have prompted the search for alternative methods of crop protection. Essential oils (EOs) are secondary metabolites of plants and have been proven to show antibacterial, antifungal, and pest-repellent properties. This study was undertaken to determine the activity of grapefruit, rosemary, pine, sage, and thyme EOs against the fungus Cercospora beticola, which is the most dangerous pathogen of sugar beet and the causal agent of Cercospora leaf spot. According to the determined Minimum Inhibitory Concentration (MIC), thyme EO was found the most effective against C. beticola. For most of the fungal isolates tested, the MIC of this EO was 0.313 mL/L. Thyme EO also inhibited the growth of multi-resistant isolates. Based on the results obtained, thyme EO was subjected to further testing in field conditions, where its efficiency in controlling C. beticola was also proven. The results indicate that the use of thyme EO may be a promising method for the protection of sugar beets, although it requires further optimization in the context of its inclusion in sustainable protection programs assuming a reduced number of synthetic fungicide treatments.

Enhancing Gene Delivery in NB-4 Cells: Overcoming Transduction and Selection Challenges

Efficient gene transduction and cell viability are critical factors in genetic manipulation for research and therapeutic purposes. In this study, we explored the challenges associated with transducing the NB-4 cell line, a well-established model for acute promyelocytic leukemia (APL), using lentiviral vectors. While the initial transduction efficiency in NB-4 cells reached approximately 30%, we observed a significant decrease in cell viability, a phenomenon not observed in other acute leukemia cell lines such as THP-1 cells. We identified that this toxicity could be mitigated by purifying viral particles through ultracentrifugation or polyethylene glycol (PEG) precipitation, indicating that toxic substances, potentially secondary metabolites released by HEK293, could be responsible for the cell death. Nevertheless, cell selection by puromycin was still ineffective; crucially, we discovered that the human phosphoglycerate kinase (hPGK) promoter, commonly used in the PLKO1 vector, may become silenced in NB-4 cells, preventing effective selection with puromycin. By replacing the hPGK promoter with the elongation factor-1 alpha (EF1α) promoter, we successfully achieved high transduction efficiency and robust selection, demonstrating the potential for this modified vector system to facilitate genetic studies in APL models. These findings provide important insights into optimizing gene transduction protocols not only for NB-4 cells but also for other challenging cell lines, offering a refined approach for gene delivery and selection in cell models.

Secondary Metabolites of Corn Silk

Secondary Metabolites of Corn Silk

Whole Genome Sequencing and Comparative Genomic Analysis of Pseudomonas aeruginosa SF416, a Potential Broad-Spectrum Biocontrol Agent Against Xanthomonas oryzae pv. oryzae

Rice is one of the most important staple crops worldwide. However, the bacterial blight of rice caused by Xanthomonas oryzae pv. oryzae (Xoo) poses a major threat to the production of rice. In this study, we isolated and identified the strain Pseudomonas aeruginosa SF416, which exhibited significant antagonistic activity against Xoo, from a soil sample collected in a winter wheat field in Shannanzhalang County, Tibet, China. The bacterial solution (BS) and cell-free supernatant (CFS) of SF416 had significant prevention effects for the bacterial blight of rice, with an efficacy of 45.1% and 34.18%, respectively, while they exhibited a slightly lower therapeutic efficiency of 31.64% and 25.09%. The genomic analysis showed that P. aeruginosa SF416 contains genes involved in cell motility, colonization, cold and hot shock proteins, antibiotic resistance, and plant growth promotion. SF416 also harbors two sets of phenazine-1-carboxylic acid (PCA) synthesis gene clusters, phz1 (phzA1-G1) and phz2 (phzA2-G2), and other phenozine product-synthesis--related genes phzS, phzM, and phzH, as well as genes in the SF416 genome that share high similarity with the ones in the genomes of P. aeruginosa M18, suggesting that the two sets of PCA synthesis gene clusters are responsible for the antagonistic effect of SF416 against Xoo. A comparative antiSMASH analysis revealed that P. aeruginosa SF416 contains 17 gene clusters related to secondary metabolite synthesis, 7 of which, encoding for pyochelin, azetidomonamide A/B, L-2-amino-4-methoxy-trans-3-butenoic acid, hydrogen cyanide, pyocyanine, pseudopaline, and bicyclomycin, are conserved in strains of P. aeruginosa. Moreover, SF416 can produce protease and siderophores and display a broad-spectrum antagonistic activity against various major plant pathogenic bacteria and fungi. The results suggest that P. aeruginosa SF416 could be a potential candidate agent for the bacterial blight of rice.

Cytotoxic Effects of Plant Secondary Metabolites and Naturally Occurring Bioactive Peptides on Breast Cancer Model Systems: Molecular Mechanisms

Breast cancer is the second leading cause of death among women, and the number of mortal cases in diagnosed patients is constantly increasing. The search for new plant compounds with antitumor effects is very important because of the side effects of conventional therapy and the development of drug resistance in cancer cells. The use of plant substances in medicine has been well known for centuries, but the exact mechanism of their action is far from being elucidated. The molecular mechanisms of cytotoxicity exerted by secondary metabolites and bioactive peptides of plant origin on breast cancer cell lines are the subject of this review.

Metabolomics reveals altered biochemical phenotype of an invasive plant with potential to impair its biocontrol agent’s establishment and effectiveness

A plausible, but largely unexplored reason for many weed biocontrol agents failing to establish or being ineffective, could involve abiotically induced changes to an invasive plants’ biochemical phenotype and consequent enhanced herbivore resistance. Considerable literature demonstrates that chemically altered plant phenotypes can impair insect life history performance. Heather beetle, (Lochmaea suturalis), introduced to control invasive heather (Calluna vulgaris) in New Zealand (NZ) was difficult to establish and displays variable effectiveness. Using UHPLC-MS non-targeted metabolomics, we analysed primary and secondary metabolites of C. vulgaris from its native range (Scotland) and it’s introduced range (NZ), between which, differences in soil nutrients and ultraviolet light exist. We also explored secondary metabolite variation between sites within each range. New Zealand samples had the highest number of amplified metabolites, most notably defensive phenylpropanoids, supporting the concept of abiotically induced upregulation of key biosynthetic pathways. Analysis of secondary metabolite variation within each range revealed differences between sites but found little correlation of phenylpropanoid levels being influenced by variable soil nutrients. These results validate questions about the possibility of abiotically altered biochemical phenotypes in invasive plants, influencing weed biocontrol agent establishment and effectiveness, and show the potential for metabolomics in assisting future, or retrospectively analysing biological control programmes.

Haploid‐Phased Chromosomal Telomere‐to‐Telomere Genome Assembly of Medicinal Plant Uncaria rhynchophylla Dissects Genetic Controls on the Biosynthesis of Bioactive Alkaloids

ABSTRACTNatural indole alkaloids provide important medicinal resources and defences to environmental stresses. The Uncaria genus is a recorded traditional medicinal woody plant with high alkaloids. Genomic insights into alkaloid variation remain elusive. Here, we have dissected the haploid‐resolved chromosomal T2T genome assembly of Uncaria rhynchophylla with a size of ~634 Mb and contig N50 of 27 Mb using PacBio HiFi long‐reads plus Hi‐C reads and anchored the contigs on 22 pairs of confirmed chromosomes. This genome contains 56% repeat sequences and ~29 000 protein‐encoding genes. U. rhynchophylla diverged from a common ancestor shared with Coffea around 20 million years ago and contains expanded and contracted gene families associated with secondary metabolites and defences/resistance to stresses. We constructed the pathway and mined genes for rhynchophylline alkaloid biosynthesis. Fifty‐three alkaloids in this pathway and eight differentially expressed genes are the keys to alkaloid accumulation. Elevated alkaloid levels are driven by high copy numbers of critical genes STRs and SGRs involved in strictosidine synthesis and hydrolysis as evidenced by phylogenetic, expression and RNA interference analyses. These results advance our genetic understanding and guide further breeding improvements, stress adaptation studies and pharmaceutical development.