Search Results (39)

The volatile organic compounds (VOCs) in Trichoderma afroharzianum ACCC 33109 have the biological activities of both hydrolytic enzymes and antimicrobial peptides to mitigate attack by phytopathogens and spread over long distances in soil. However, the biosynthesis pathway of anti-fungal VOCs has not been elucidated yet. In this study, we identified 15 genes (TaTS1–15) coding for putative terpene synthase with low identities (<79.54%) to functionally characterized homologs through genome mining. Upon Fusarium induction, the relative expression levels of nine TaTS genes were up-regulated by up to 2793-fold (TaTS9). To verify the contribution of TaTS9 to the synthesis of anti-fungal VOCs, the TaTS9 knockout mutant strain was constructed and characterized by its antagonistic activities, transcript profiles, and VOC metabolomes. Heterologous expression of TaTS9 in Escherichia coli produced the target gene product, which converted the precursor farnesyl pyrophosphate (FPP) into β-cubenene (>90%) and γ-amorphene. Thus, TaTS9 was confirmed as the first β-cubenene synthase of Trichoderma, which catalyzes the biosynthesis of various sesquiterpenes with anti-fungal activities. This study provides insight into the key terpene synthase gene in the biosynthesis of anti-fungal sesquiterpenoids for potential applications in the agriculture and food industries. Full article

Sandalwood essential oil is extracted from the heartwood part of mature sandalwood and is known for its pleasant fragrance and exceptional medicinal activities, including antimicrobial, antitumor, and anti-inflammatory properties. The (Z)-α-santalol and (Z)-β-santalol are the most vital ingredients contributing to sandalwood oil’s bioactivities and unique woody odor characteristics. Metabolic engineering strategies have shown promise in transforming microorganisms such as yeast and bacteria into effective cell factories for enhancing the production of vital sesquiterpenes (santalene and santalol) found in sandalwood oil. This review aims to summarize sources of sandalwood oil, its components/ingredients, and its applications. It also highlights the biosynthesis of santalene and santalol and the various metabolic engineering strategies employed to reconstruct and enhance santalene and santalol biosynthesis pathways in heterologous hosts. Full article

Trichothecenes are sesquiterpenoid toxins produced by diverse ascomycetes, including Fusarium. The trichothecene analog deoxynivalenol (DON) produced by the Fusarium head blight (FHB) pathogen Fusarium graminearum is a virulence factor on wheat and a major food and feed safety concern. In Fusarium, the trichothecene biosynthetic gene (TRI) cluster consists of 7–14 genes. Most TRI cluster genes are conserved and their specific roles in trichothecene biosynthesis have been determined. An exception is TRI14, which is not required for DON synthesis in vitro but is required for spread of F. graminearum in wheat heads. In the current study, gene expression analyses revealed that TRI14 was highly induced in infected wheat heads. We demonstrated that TRI14 was not only required for F. graminearum spread but also important for initial infection in wheat. Although a prior study did not detect DON in infected seeds, our analyses showed significantly less DON and fungal biomass in TRI14-mutant (designated ∆tri14)-inoculated heads than wild-type-inoculated heads. Gene expression comparison showed that the level of expression of TRI genes was similar in the wheat tissues infected with ∆tri14 or the wild type, indicating the reduced toxin levels caused by ∆tri14 may be due to less fungal growth. ∆tri14 also caused less lesion and grew less in wheat coleoptiles than the wild type. The growth of ∆tri14 in carboxymethylcellulose medium was more sensitive to hydrogen peroxide than the wild type. The data suggest that TRI14 plays a critical role in F. graminearum growth, and potentially protects the fungus from plant defense compounds. Full article

Caoyuanheimo-1 (Agaricus sp.) is a delectable mushroom native to Inner Mongolia, China, belonging to the Agaricus genus and valued for both its edible and medicinal properties. Although it has been cultivated to a certain extent, the molecular mechanisms regulating its development remain poorly understood. Building on our understanding of its growth and development conditions at various stages, we conducted transcriptomic and metabolomic studies to identify the differentially expressed genes (DEGs) and metabolites throughout its growth cycle. Simultaneously, we analyzed the synthesis pathways and identified several key genes involved in the production of terpenoids, which are secondary metabolites with medicinal value widely found in mushrooms. A total of 6843 unigenes were annotated, and 449 metabolites were detected in our study. Many of these metabolites and differentially expressed genes (DEGs) are involved in the synthesis and metabolism of amino acids, such as arginine, cysteine, methionine, and other amino acids, which indicates that the genes related to amino acid metabolism may play an important role in the fruiting body development of Caoyuanheimo-1. Succinic acid also showed a significant positive correlation with the transcriptional level changes of nine genes, including laccase-1 (TRINITY_DN5510_c0_g1), fruiting body protein SC3 (TRINITY_DN3577_c0_g1), and zinc-binding dihydrogenase (TRINITY_DN2099_c0_g1), etc. Additionally, seventeen terpenoids and terpenoid-related substances were identified, comprising five terpenoid glycosides, three monoterpenoids, two diterpenoids, one sesquiterpenoid, one sesterterpenoid, two terpenoid lactones, and three triterpenoids. The expression levels of the genes related to terpenoid synthesis varied across the three developmental stages. Full article

Pruning is an important agronomic measure in tea plantation management. In this study, we analyzed the effect of pruning on gene expression in tea leaves from a transcriptomics perspective and verified the results of a transcriptomic analysis in terms of changes in physiological indicators of tea leaves. The results showed that pruning enhanced the gene expression of nine metabolic pathways in tea leaves, including fatty acid synthesis and carbohydrate metabolism, nitrogen metabolism, protein processing in the endoplasmic reticulum, and plant hormone signal transduction, thereby promoting the growth of tea plants and increasing tea yield. However, pruning reduced the gene expression of nine metabolic pathways, including secondary metabolites biosynthesis, flavonoid biosynthesis, phenylpropanoid biosynthesis, and sesquiterpenoid and triterpenoid biosynthesis, and lowered the content of caffeine, flavonoids, and free amino acids in tea plant leaves. In conclusion, pruning could promote the growth of tea plants and increase the yield of tea, but it was not conducive to the accumulation of some quality indicators in tea leaves, especially caffeine, flavonoids, and free amino acids, which, in turn, reduced the quality of tea. This study provides an important theoretical reference for the management of agronomic measures in tea plantations. Full article

Nanmu (Phoebe zhennan) has a unique fragrance and is a high-quality tree species for forest conservation. The types and contents of volatile compounds in different tissues of nanmu wood are different, and the study of its volatile metabolites can help us to understand the source of its fragrance and functions. In order to explore the metabolites related to the wood fragrance of nanmu and to find out the unique volatile substances in the heartwood, gas chromatography–mass spectrometry (GC-MS) was performed to analyze the non-targeted metabolomics in five radial tissues from the sapwood to the heartwood of nanmu. A total of 53 volatile metabolites belonging to 11 classes were detected in all tissues, including terpenes, aromatic hydrocarbons, organoheterocyclics, phenols, esters, organic acids, alcohols, alkaloids, alkane, indoles derivatives, and others. And most of the volatile metabolites were identified for the first time in nanmu wood. Among them, terpenes and aromatic hydrocarbons were the main volatile components. In addition, 22 differential metabolites were screened from HW and SW, HW, and TZ via metabolomic analysis. Among these DAMs, three volatile metabolites (cadinene, a sesquiterpenoid; p-cymene, a monoterpenoid; 1,3,5-triisopropylbenzene, an aromatic hydrocarbon) contributed heavily to the characteristic fragrance of the heartwood. Additionally, the expression of transcripts showed that the unigenes in the terpenoid biosynthesis pathway were especially up-regulated in the SW. Therefore, we speculated that fragrance-related metabolites were synthesized in SW and then deposited in heartwood during sapwood transformed to heartwood. The expression levels of transcription factors (e.g., WRKY, C2H2, NAC) acted as the major regulatory factors in the synthesis of terpenoid. The results lay the foundations for further studies on the formation mechanism of fragrance components in nanmu wood and also provide a reference for the further development and utilization of nanmu wood. Full article

Blueberry is a nutrient-rich berry, and its taste and flavor directly determine the consumer preference. Until now, few studies have focused on the comparison of fresh food quality and the key metabolites in superior fresh-eating blueberry cultivars. Herein, fruit quality indicators of 10 highbush blueberry cultivars were evaluated using ‘Bluerain’ as the control. Appearance quality analysis of fruits showed that ‘Brigitta’ had a larger fruit size and ‘Anna’ was the smallest. ‘Anna’ fruits, followed by ‘O′Neal’, had the highest ratio of soluble solids to acidity because of their lowest titratable acidity content. Despite the high soluble sugar content, the antioxidants in ‘Anna’ fruits such as total flavonoids, anthocyanins and vitamin C were lowest among all cultivars, while ‘Duke’ seemed to have opposite patterns. Furthermore, a total of 553 and 557 metabolites were identified by non-targeted metabolomics liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive and negative ion mode, respectively. Particularly, the numbers of differentially accumulated metabolites (DAMs) were the most between the ‘O′Neal’ vs. ‘Bluerain’ group. The DAMs involved in the metabolic pathways, sesquiterpenoid and triterpenoid biosynthesis, monoterpenoid biosynthesis, galactose metabolism, starch and sucrose metabolism, may be mainly related to the synthesis of flavor and carbohydrate substances. Moreover, the expression patterns of genes involved in sugar metabolism were verified by quantitative real-time PCR (qRT-PCR) analysis in different cultivars. Therefore, the systematical comparison of the quality characteristics, metabolites and expression profiles of related genes in highbush blueberries with good flavor could provide some basis for further research on fresh fruit breeding of blueberries. Full article

The essential oil of Cinnamomum burmannii (Nees and T. Nees) Blume is rich in monoterpenes and sesquiterpenes. The post-transcriptional regulatory mechanisms controlling the expression of terpenoid-related genes have not yet been clarified in C. burmannii. Here, we conducted a metabolomic analysis of the leaves of C. burmannii across four developmental stages using gas chromatography–mass spectrometry. We also identified miRNAs and their target genes involved in terpenoid biosynthesis using small RNA sequencing. A total of 135 differentially expressed metabolites were detected, including 65 terpenoids, 15 aldehydes, and 13 benzenes. A total of 876 miRNAs from 148 families were detected, among which 434 miRNAs were differentially expressed, including three known miRNAs and 431 novel miRNAs. Four miRNAs (gma-miR5368, novel_miR_377, novel_miR_111, and novel_miR_251) were predicted to regulate the expression of four differential expressed genes involved in the monoterpenoid and sesquiterpenoid synthesis. miRNAs families miR396, miR5185, and miR9408 were predicted to play diverse regulatory roles in monoterpenoid and sesquiterpenoid synthesis during the leaf development of C. burmannii. The results of our study shed new light on the roles of regulatory genes in terpenoid biosynthesis. Our findings also have implications for the further promotion of essential oil production using the leaves of C. burmannii. Full article

The red root of Salvia miltiorrhiza Bunge, a famous traditional Chinese medicine (TCM), was caused by tanshinone in epidermis cells. In order to study the biological function of ncRNAs in the tanshinone synthesis, the expression patterns of mRNA and ncRNAs were comprehensively analyzed in red (high tanshinone content) and white root (low tanshinone content) tissues derived from the same plant. A total of 731 differentially expressed genes (DEGs) were mainly enriched in primary metabolic pathways such as galactose and nitrogen, and some secondary metabolic pathways such as phenylpropanoid and terpenoids. A total of 70 miRNAs, 48 lncRNAs, and 26 circRNAs were identified as differentially expressed (DE) ones. The enrichment pathway of the targets of DE-lncRNA were mainly in ribosome, carbon metabolism, plant hormone signal transduction, and glycerophospholipid metabolism. The function of the targets genes of 59 miRNAs combined with DE-circRNAs was mainly involved in plant–pathogen interaction, endocytosis, phenylpropanoid biosynthesis, and sesquiterpenoid and triterpenoid biosynthesis pathways. Most genes of the tanshinone synthesis pathway had a higher expression. Some ncRNAs were predicted to regulate several key enzyme genes of the tanshinone synthesis pathway, such as SmDXS2, SmGGPPS1, SmKSL. Furthermore, most target genes were related to the resistance of pathogens. The present study exhibited the tissue-specific expression patterns of ncRNAs, which would provide a basis for further research into the regulation mechanism of ncRNAs in the tanshinone synthesis process. Full article

Herein we report a feasible study concerning the synthesis and the in vitro antimicrobial activity of some new homodrimane sesquiterpenoids with a benzimidazole unit. Based on some homodrimane carboxylic acids, on their acyl chlorides and intermediate monoamides, a series of seven N-homodrimenoyl-2-amino-1,3-benzimidazoles and 2-homodrimenyl-1,3-benzimidazoles was synthesized. The syntheses involved the decarboxylative cyclization and condensation of the said acids or acyl chlorides with o-phenylendiamine and 2-aminobenzimidazole, as well as the p-TsOH-mediated cyclodehydration of the said monoacylamides. The structures of the synthesized compounds have been fully confirmed, including by the X-ray diffraction. Their biological activities were evaluated on five species of fungi (Aspergillus niger, Fusarium solani, Penicillium chrysogenum, P. frequentans, and Alternaria alternata) and two strains of bacteria (Bacillus sp. and Pseudomonas aeruginosa). Compounds 7 and 20 showed higher antifungal (MIC = 0.064 and 0.05 μg/mL) and antibacterial (MIC = 0.05 and 0.032 μg/mL) activities compared to those of the standards: caspofungin (MIC = 0.32 μg/mL) and kanamycin (MIC = 2.0 μg/mL), and compounds 4, 10, 14, and 19 had moderate activities. Full article

The essential oil of German chamomile (Matricaria recutita L.) is widely used in food, cosmetics, and the pharmaceutical industry. α-Bisabolol is the main active substance in German chamomile. Farnesyl diphosphate synthase (FPS) and α-bisabolol synthase (BBS) are key enzymes related to the α-bisabolol biosynthesis pathway. However, little is known about the α-bisabolol biosynthesis pathway in German chamomile, especially the transcription factors (TFs) related to the regulation of α-bisabolol synthesis. In this study, we identified MrFPS and MrBBS and investigated their functions by prokaryotic expression and expression in hairy root cells of German chamomile. The results suggest that MrFPS is the key enzyme in the production of sesquiterpenoids, and MrBBS catalyzes the reaction that produces α-bisabolol. Subcellular localization analysis showed that both MrFPS and MrBBS proteins were located in the cytosol. The expression levels of both MrFPS and MrBBS were highest in the extension period of ray florets. Furthermore, we cloned and analyzed the promoters of MrFPS and MrBBS. A large number of cis-acting elements related to light responsiveness, hormone response elements, and cis-regulatory elements that serve as putative binding sites for specific TFs in response to various biotic and abiotic stresses were identified. We identified and studied TFs related to MrFPS and MrBBS, including WRKY, AP2, and MYB. Our findings reveal the biosynthesis and regulation of α-bisabolol in German chamomile and provide novel insights for the production of α-bisabolol using synthetic biology methods. Full article

Zerumbone is a multifunctional compound with antimicrobial, antitumor, hyperalgesic, antioxidant and anti-inflammatory applications, and constitutes a point molecule for the future synthesis of derivatives with improved efficiency. This monocyclic sesquiterpenoid is found in high content in wild ginger (Zingiber zerumbet Smith), a perennial herb with economic importance as an ornamental as well as a medicinal plant. The presence of zerumbone is a distinctive feature that allows identification and differentiation from other species, not only in Zingiber, but also in Curcuma, Alpinia, Boesenbergia, Ethlingera and Ammomum spp., as well as related families (Costaceaee). To successfully use zerumbone in areas such as medicine, food and agriculture, further research on improving its low solubility and bioavailability, as well as its preservation, is a major current priority. In addition, despite its promising pharmacological activities, preclinical and clinical studies are required to demonstrate and evaluate the in vivo efficacy of zerumbone. Full article

Fungal biotransformation is an attractive synthetic strategy to produce highly specific compounds with chemical functionality in regions of the carbon skeleton that are not easily activated by conventional organic chemistry methods. In this work, Cladosporium antarcticum isolated from sediments of Glacier Collins in Antarctica was used to obtain novel drimane sesquiterpenoids alcohols with activity against Candida yeast from drimendiol and epidrimendiol. These compounds were produced by the high-yield reduction of polygodial and isotadeonal with NaBH₄ in methanol. Cladosporium antarcticum produced two major products from drimendiol, identified as 9α-hydroxydrimendiol (1, 41.4 mg, 19.4% yield) and 3β-hydroxydrimendiol (2, 74.8 mg, 35% yield), whereas the biotransformation of epidrimendiol yielded only one product, 9β-hydroxyepidrimendiol (3, 86.6 mg, 41.6% yield). The products were purified by column chromatography and their structure elucidated by NMR and MS. The antifungal activity of compounds 1–3 was analyzed against Candida albicans, C. krusei and C. parapsilosis, showing that compound 2 has a MIC lower than 15 µg/mL against the three-pathogenic yeast. In silico studies suggest that a possible mechanism of action for the novel compounds is the inhibition of the enzyme lanosterol 14α-demethylase, affecting the ergosterol synthesis. Full article

Drimys winteri J.R. (Winteraceae) produce drimane sesquiterpenoids with activity against Candida yeast. In this work, drimenol, polygodial (1), isotadeonal (2), and a new drimane α,β-unsaturated 1,4-dialdehyde, named winterdial (4), were purified from barks of D. winteri. The oxidation of drimenol produced the monoaldehyde drimenal (3). These four aldehyde sesquiterpenoids were evaluated against six Candida species isolated from candidemia patients in Chilean hospitals. Results showed that 1 displays fungistatic activity against all yeasts (3.75 to 15.0 µg/mL), but irritant effects on eyes and skin, whereas its non-pungent epimer 2 has fungistatic and fungicide activities at 1.9 and 15.0 µg/mL, respectively. On the other hand, compounds 3 and 4 were less active. Molecular dynamics simulations suggested that compounds 1–4 are capable of binding to the catalytic pocket of lanosterol 14-alpha demethylase with similar binding free energies, thus suggesting a potential mechanism of action through the inhibition of ergosterol synthesis. According to our findings, compound 2 appears as a valuable molecular scaffold to pursue the future development of more potent drugs against candidiasis with fewer side effects than polygodial. These outcomes are significant to broaden the alternatives to treat fungal infections with increasing prevalence worldwide using natural compounds as a primary source for active compounds. Full article

Aromatic essential oils play a significant role in pharmaceuticals, food additives, cosmetics, and perfumery. Essential oils mostly comprise aliphatic hydrocarbons, monoterpenoids, sesquiterpenoids and diterpenes. Plant extracts comprise a complex mixture of terpenes, terpenoids, aliphatic and phenol-derived aromatic components. Terpenes are a significant class of hydrocarbons with numerous health benefits. These biological functions of essential oil components are examined in vitro and in vivo studies. Some studies evaluated the properties and functions of α-phellandrene (α-PHE). Detailed evaluation to determine the functions of α-PHE over a spectrum of health care domains needs to be initiated. Its possible mechanism of action in a biological system could reveal the future opportunities and challenges in using α-PHE as a pharmaceutical candidate. The biological functions of α-PHE are reported, including anti-microbial, insecticidal, anti-inflammatory, anti-cancer, wound healing, analgesic, and neuronal responses. The present narrative review summarizes the synthesis, biotransformation, atmospheric emission, properties, and biological activities of α-PHE. The literature review suggests that extended pre-clinical studies are necessary to develop α-PHE-based adjuvant therapeutic approaches. Full article