Endophytic Research Articles

The impact of pine wilt disease on the endophytic microbial communities structure of Pinus koraiensis.

Pine Wilt Disease (PWD) is a devastating pine tree disease characterized by rapid onset, high mortality rate, quick spread, and difficulty in control. Plant microbiome plays a significant role in the development of PWD. However, the endophytic microbial communities of Pinus koraiensis infected by pine wood nematode (PWN) Bursaphelenchus xylophilus remain largely unexplored. In this study, we analyzed the structural changes of endophytic communities of P. koraiensis after infection by the PWN using high-throughput sequencing technology. The results showed that the community structure underwent significant changes as the degree of PWN infection intensified. The diversity and abundance of endophytic fungi in P. koraiensis increased, while those of endophytic bacteria in P. koraiensis decreased during the infection process. Meanwhile, the abundance of some dominant microorganisms has also changed, including species such as Graphilbum and Pseudoalteromonas. Functional prediction analysis showed that the functional composition of endophytic fungi in P. koraiensis was significantly different across the development of PWD, while the composition of endophytic bacteria remained essentially similar. The results indicated that PWN infection had a significant impact on the structure, diversity, abundance, and functional gene composition of endophytic microbial communities in P. koraiensis, and most of the main endophytic microbial groups tended to coordinate with each other. This work provides a better understanding of the changes in endophytic community structure and function caused by PWD infection of P. koraiensis, which may benefit the exploration of potential endophytes for PWN biocontrol.

Cytochalasin H enhances sensitivity to gefitinib in non-small-cell lung cancer cells through inhibiting EGFR activation and PD-L1 expression

In our previous study, we have isolated cytochalasin H (CyH) from endophytic fungus derived from mangrove plant and found that CyH inhibited the proliferation of non-small cell lung cancer (NSCLC) cells. Recently, epidermal growth factor receptor (EGFR) activation and programmed cell death 1 ligand (PD-L1) expression have been demonstrated to mediate NSCLC resistance to gefitinib, first-generation EGFR tyrosine kinase inhibitor (EGFR-TKI). Here, we further investigated the effect of CyH on EGFR activation, PD-L1 expression, and gefitinib sensitivity in NSCLC cell lines, A549 (wild-type EGFR), HCC827 (EGFR mutation), and NCI-H1975 (dual EGFR mutations and acquired gefitinib resistance) and animal model. Our results showed that CyH significantly inhibited EGFR activation and PD-L1 expression in NSCLC cells. Additionally, CyH dramatically promoted the inhibitory effect of gefitinib on the proliferation of A549 and HCC827 cells, and enhanced the sensitivity to gefitinib in NCI-H1975 cells. Moreover, CyH increased the inhibitory effect of gefitinib on EGFR activation and PD-L1 expression in HCC827 and NCI-H1975 cells. Animal experiments further demonstrated that CyH significantly promoted the inhibitory effect of gefitinib on the growth of NSCLC and the expression of Ki-67, p-EGFR, and PD-L1 in NCI-H1975 NSCLC xenograft tumors of nude mice. Furthermore, CyH inhibited the activation of JAK3/STAT signaling pathway. Taken together, our findings suggest that CyH promotes the sensitivity to gefitinib in NSCLC cells through the inhibition of EGFR activation and PD-L1 expression.

Antiprotozoal Natural Products from Endophytic Fungi Associated with Cacao and Coffee.

Collectively, leishmaniasis and Chagas disease cause approximately 8 million cases and more than 40,000 deaths annually, mostly in tropical and subtropical regions. The current drugs used to treat these diseases have limitations and many undesirable side effects; hence, new drugs with better clinical profiles are needed. Fungal endophytes associated with plants are known to produce a wide array of bioactive secondary metabolites, including antiprotozoal compounds. In this study, we analyzed endophytic fungal isolates associated with Theobroma cacao and Coffea arabica crop plants, which yielded extracts with antitrypanosomatid activity. Crude extracts were subjected to bioassay-guided isolation by HPLC, followed by spectrometric and spectroscopic analyses via mass spectrometry (MS) and nuclear magnetic resonance (NMR), Results: Compounds 1-9 were isolated and displayed novel antitrypanosomal and antileishmanial activities ranging from 0.92 to 32 μM. Tandem liquid chromatography-mass spectrometry (LC-MS) analysis of the organic extracts from different strains via the feature-based Global Natural Products Social (GNPS) molecular networking platform allowed us to dereplicate a series of metabolites (10-23) in the extracts. Molecular docking simulations of the active compounds, using the 3-mercaptopyruvate sulfurtransferase protein from L. donovani (Ld3MST) and the cruzipain enzyme from T. cruzi as putative molecular targets, allowed us to suggest possible mechanisms for the action of these compounds. The isolation of these antiprotozoal compounds confirms that crop plants like coffee and cacao harbor populations of endophytes with biomedical potential that confer added value to these crops.

Endophytic fungus regulates the root secretion of IAA and ABA to increase rice nitrogen accumulation by promoting soil nitrogen fixation

Endophytic fungus regulates the root secretion of IAA and ABA to increase rice nitrogen accumulation by promoting soil nitrogen fixation

Influence of endophytic fungi treatments on aluminum contents in Vernicia montana seedlings and soils under different concentrations of aluminum stress

Although leveraging the interaction with endophytic fungi is an efficient and environment-friendly strategy for plants to enhance growth and resistance, how different endophyte species influence host plants’ resilience in adverse conditions remain comparatively unclear. In order to explore the effect of endophytic fungi on the aluminum resistance of woody host plants, Vernicia montana seedlings were subjected to different aluminum concentrations (T0, T1, T2, T3, T4) in this study. The aluminum contents in roots, leaves and rhizospheric soil of V. montana seedlings were determined after applying endophyte suspensions of Pestalotiopsis (NP), Alternaria (LA), Penicillium (QP), Coniothyrium (DC) and Thermophilic (ST) spp. The results showed that aluminum stress treatment, endophytic fungi treatment and their interaction had significant effects on aluminum content in leaves, aluminum content in roots, aluminum content in rhizospheric soil, and the transport and retention rate of aluminum ions in soil-root-leaf. With the increase of aluminum concentrations, the aluminum content in leaves of V. montana increased in the endophyte treatments of LA and ST, decreased in CK, NP and DC, or had marginal variation in QP treatment. Compared with T0, four endophyte treatments of LA, QP, DC and ST significantly reduced root aluminum content under T4 concentration (P < 0.05), contrary to the results of NP treatment. Endophyte treatments significantly increased root aluminum content of V. montana under T1 concentration (P < 0.05). The foliar Al content in fungi-inoculated seedlings was significantly lower than that of the non-inoculated ones under T0 and T3 levels (P < 0.05), the LRR is less than 1, while the opposite trend was observed under T2 and T4 treatments. The aluminum transport coefficient TFsoil-root and TFroot-leaf increased in different proportions under the same aluminum concentration. The findings indicate that the application of endophytic fungi change the aluminum contents and transport from rhizospheric soil, roots to leaves. The specific effects of endophytic fungi vary with the degree of aluminum stress and the fungi genus. The study proves that inoculation of endophytic fungi can improve the aluminum tolerance of host plants, and thereby play an important role in promoting the sustainable development of forestry.

Solanapyrone analogues from endophytic Nigrospora sphaerica MZW-A associated with the endangered conifer Pinus wangii

Eight previously undescribed solanapyrone analogues, sphasolanapyrones A–H (1–8), together with four structurally related known compounds (9–12) were obtained from the solid fermentation of Nigrospora sphaerica MZW-A, an endophytic fungus isolated from the fresh branches of the endangered conifer Pinus wangii. This study represents the first investigation on the secondary metabolites of endophytic fungus associated with this precious plant. The structures and absolute configurations of compounds 1–8 were elucidated by extensive spectroscopic analysis and electronic circular dichroism (ECD) calculations. 1 and 2 are first examples of 3,4-vic diol solanapyrone analogues, whereas 7 and 8 are rare 17-nor-solanapyrones. Among these isolates, 3, 4, 5, and 11 showed weak inhibitory against Staphylococcus aureus. In addition, compound 5 displayed weak cytotoxic effects against several tumor cell lines.

Insights into the Rooting and Growth-Promoting Effects of endophytic Fungus Serendipita indica in Blueberry (Vaccinium corymbosum)

Insights into the Rooting and Growth-Promoting Effects of endophytic Fungus Serendipita indica in Blueberry (Vaccinium corymbosum)

Talarmalnoids A–F: Fusicoccane diterpenoids from an arthropod-derived endophytic fungus Talaromyces malicola

The metabolites from the endophytic fungus Talaromyces malicola hosted in the gastrointestinal tract of the arthropods Armadillidium vulgare were investigated, and six undescribed fusicoccane diterpenoids, talarmalnoids A–F (1–6), along with three known analogs were isolated. Talarmalnoid C (3) was an unprecedented fusicoccane diterpenoid with two sugar units, i.e., 6-O-methyl-α-d-glucose and α-d-glucose. Talarmalnoids D and E (4 and 5) were fusicoccane-type diterpenoids with unusual seven-membered rings attached at the C-3′ and C-4′ positions. Their structures and absolute configurations were identified by NMR, HRESIMS analyses, X-ray single crystal diffraction, GC–MS, ECD analyses, 13C NMR calculations, and DP4+ probability analyses. Bioassay results showed that talarmalnoid B (2) exhibited significant inhibitory activities against the LPS-inducted production of NO in RAW 264.7 cells, with IC50 value of 0.83 μM.

Corrective role of endophytic exopolysaccharides from Clerodendrum infortunatum L. on arsenic-induced ovarian steroidogenic dysfunction and associated inflammatory responses

The present investigation aimed to evaluate the therapeutic potential of exopolysaccharides (EPSs) derived from endophytic fungi against arsenic [As(III)]-mediated metabolic and reproductive ailments. Two endophytic fungi, Diaporthe arengae (CleR1) and Fusarium proliferatum (CleR3), were isolated from Clerodendrum infortunatum (Cle), and used for the extraction of two types of EPSs. GC–MS analysis confirmed the presence of hydroxymethyl furfural (HMF) and α-d-glucopyranose in the EPS1 (CleR1) and EPS2 (CleR3), respectively. FTIR analysis revealed the potential As(III)-chelation properties of both EPSs. EPS1 and EPS2 significantly mitigated As(III)-induced oxidative stress and lipid peroxidation by restoring the activities of antioxidative enzymes. EPSs successfully corrected the gonadotropin imbalance and steroidogenic alterations. The downregulation of proinflammatory (NF-κB and TNF-α) and proapoptotic (BAX) mediators and the upregulation of antiapoptotic (Bcl-2) markers were also detected following the treatment with EPSs. Histomorphological restoration of reproductive and metabolic organs was also observed in both the EPS groups. Moreover, the As(III)-induced increase in the immunoreactivity of the androgen receptor (AR) was successfully reversed by these EPSs. Molecular docking predicted that HMF and α-d-glucopyranose of EPS1 and EPS2 interact with the active site of AR by limiting its activity. Hence, EPS could be effective for developing new therapeutic strategies for managing As(III) toxicity.

Peanut-Colonized Piriformospora indica Enhanced Drought Tolerance by Modulating the Enzymes and Expression of Drought-Related Genes.

Peanut (Arachis hypogaea L.) is an important cash and oil seed crop, mostly distributed in arid and semi-arid areas. In recent years, due to the influence of atmospheric circulation anomalies and other factors, drought has become frequent and increasingly serious in China. This has posed serious challenges to peanut production. The objective of this study was to investigate the potential of the endophytic fungus Piriformospora indica to form a symbiotic relationship with peanut plants and to evaluate the drought tolerance of P. indica-colonized peanut plants subjected to a simulated drought stress treatment using 20% polyethylene glycol 6000 (PEG6000). The endophytic fungus P. indica affected the physiological characteristics of the host plant by colonizing the plant roots, thereby conferring greater resistance to drought stress. This fungus strongly colonized the roots of peanuts and was found to enhance root activity after 24 h of P. indica colonization under PEG6000. Catalase (CAT) and peroxidase (POD) activities were increased at 24 h in peanut leaves colonized with P. indica. Expression of drought-related genes, such as AhNCED1, AhP5CS, and DREB2A was upregulated at 24 h of P. indica colonization. In addition, after PEG6000 treatment, proline, soluble protein, and abscisic acid (ABA) concentrations in plants were increased, while the accumulation of malondialdehyde (MDA), and hydrogen peroxide (H2O2) was decreased in P. indica colonized peanut. In conclusion, P. indica mediated peanut plant protection against the detrimental effects of drought resulted from enhanced antioxidant enzyme activities, and the upregulated expression of drought-related genes for lower membrane damage.

New Isocoumarins from An Endophytic Fungal Strain Diaporthe arengae M2 and Their Antibacterial Activities.

Four new isocoumarin derivatives 12-O-acetyl-isocitreoisocoumarinol (1), (+)-(10R)-O-acetyl-diaportinol (2-a), (-)-(10S)-O-acetyl-diaportinol (2-b), peyroisocoumarin E (3) and new stereoconfigurations of three isocoumarin derivatives desmethyldichlorodiaportinol A (4), threo-monochlorodiaportinol A (5-a), erytheo-monochlorodiaportinol A (5-b), together with nine known ones (6-14), were separated from the rice fermentation of endophytic fungus Diaporthe arengae M2 isolated from Camellia oleifera. The structures of new compounds were determined by extensive spectroscopic analyses including nuclear magnetic resonance (NMR) and high resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Compounds 4, 7, 8, 12, 13 exhibited definite inhibition against five strains of bacteria with the MIC values range from 16 μg/mL to 64 μg/mL.

Temporal host–symbiont dynamics in community contexts: Impacts of host fitness and vertical transmission efficiency on symbiosis prevalence

Abstract Symbiotic associations play a role in plant ecology and evolution, but the outcome of the interaction depends on the life‐history traits of the partners and the environmental context. Although symbiosis with vertically transmitted microorganisms should result in mutualism, it is not clear how the transmission process aligns with the outcome of the context‐dependent symbiosis. For 3 years, we sampled individuals of an annual plant species that forms symbiosis with a vertically transmitted fungal endophyte, in paired stands of two contrasting vegetation communities (humid mesophytic meadows [HMM]: productive/low stress, and humid prairies [HP]: less productive/high stress). We estimated the prevalence of symbiosis at the population level, and the fitness of the plant, the symbiotic status and vertical transmission efficiency at the individual level. Over 3 years, the prevalence of symbiosis was ≈100% in HMM and ≈75% in HP. Plant fitness was very low and high in years with precipitation below and above the yearly mean, respectively. The higher fitness of endophyte‐symbiotic plants was evident in the HMM and high precipitation years. Vertical transmission of endophytes was higher in HMM (≈96%) compared to HP (≈93%) and was not related to plant fitness. Despite transmission inefficiencies in HP, changes in prevalence within the growing season (from seeds to the final plant stand) suggest a fitness advantage for symbiotic plants. Vertical transmission is expected to promote mutualism as it aligns partners' fitness. Although symbiotic plants showed higher fitness and the probability of transmission failures was higher among low‐fitness plants, the variation in transmission efficiency between plants and vegetation communities was not related to the fitness of the individual host. Our study provides evidence that context‐dependent vertical transmission efficiency and endophyte‐mediated fitness advantages interact complexly to determine the prevalence of symbiosis in populations that occur in contrasting vegetation communities. Read the free Plain Language Summary for this article on the Journal blog.

Biotransformation of Glaucic Acid Isolated from the Root of Lindera glauca by the Endophytic Fungi Penicillium Chrysogenum SHJ-07.

Glaucic acid isolated from the root of Lindera glauca, was investigated by the biotransformation methods via the endophytic fungi, resulting in the production of five new glausesquiterpenes A-E (1-5), along with a known analogue 6. Their structures were elucidated based on spectroscopic methods and electronic circular dichroism (ECD) calculations. In the bioassays, glausesquiterpene A (1) showed good inhibitory activity of NO production in LPS-activated RAW 264.7 macrophages with an IC50 value of 20.1 μM than positive control (Indomethacin, IC50 24.1 μM). Further in vitro studies demonstrated that glausesquiterpene A significantly suppressed the protein expression of iNOS and COX-2 at the concentration of 25.0 μM.

Variations in the root mycobiome and mycorrhizal fungi between different types of Vanilla forest farms on Réunion Island.

The mycorrhizal fungi of cultivated Vanilla spp. have mainly been studied in America, while a recent study has investigated them on Réunion Island (Indian Ocean). However, there are many different types of cultivation on Réunion, from shade-house crops to forest farms of endemic or exotic trees. Here we fill a gap in the study of the root mycobiome of Vanilla by sampling vines in forest plantations on recent lava flows in the southeast of Réunion. Specifically, we aimed to characterize the fungal communities between terrestrial and epiphytic roots, between forest farms that differ mainly in the species of trees, and between Vanilla roots and ECM-like roots of nearby trees. By sequencing fungal ITS2, we showed that the Vanilla root mycobiome is diverse and differed between the root types and forest farms. Epiphytic and terrestrial roots host endophytic fungi, while a putative rust with visible urediniospores was abundant in terrestrial roots mainly. Other pathogens were detected in epiphytic roots (Colletotrichum) with no sign of disease. Following sequencing and electron microscopy, Tulasnellaceae, characterized by imperforate parenthesomes and cell wall expansion with an amorphous matrix, were shown to be the main mycorrhizal fungi in both vanilla root types. Interestingly, the dominant Tulasnellaceae OTU was found in ECM-type roots of trees belonging to the ectomycorrhizal family Sapotaceae. Further observations are needed to confirm the ectomycorrhizal association of endemic trees with Tulasnella. Moreover, labeling experiments will be instrumental in investigating the transfer of nutrients between the trees and the Vanilla through the network of mycorrhizal associations in the soil.

Steroids produced by Cladosporium anthropophilum, an endophytic fungus Isolated from Avicennia marina (Forssk.) Vierh and Their Antibacterial Activity

This work was conducted to isolate the steroid compounds from an endophytic fungus Cladosporium anthropophilum and determine their effects against 4 strains of bacteria. The fungi were afforded from a mangrove plant Avicennia marina (Forssk.) Vierh of Acanthaceae family, growing in West Java, Indonesia. The fermentation and isolation of C. anthropophilum yielded 3 ergostane-type steroids including a highly oxidized one, identified as penicisteroid A (1), ergosterol (2), and ergosterol-5,8-peroxide (3), together with 2 stigmastanes, characterized as stigmasterol (4), and stigmasterol-5,8-peroxide (5). The elucidation structure of all isolated steroids was performed by extensive spectroscopic measurements (MS, IR, 1D, and 2D NMR) and supported by a comparison of previously reported spectral data. Subsequently, the potential of the 5 steroids as well as methanol, n-hexane, and ethyl acetate extracts were evaluated against 2 Gram-positive bacteria, Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 29212 and 2 Gram-negative bacteria, Vibrio harveyi ATCC 5339 and Escherichia coli ATCC 25922. The results showed that none of the isolated steroids were active, while the 3 extracts exhibited significant inhibition against all the tested bacteria’s growth and enabled us to propose the synergistic effects between active compounds in these extracts and their antibacterial activity. HIGHLIGHTS An isolated and identified endophytic fungus, Cladosporium anthropophilum, from a mangrove plant Avicennia marina (Forssk.) Vierh yielded five steroids. A chromatography technique and spectroscopic method were utilized for separation processes and structure determination, respectively. An antibacterial assay against two Gram-positive bacteria ( aureus and E. faecalis) and two Gram-negative bacteria (V. harveyi and E. coli) implied the synergistic effects between five isolated steroids and their parent extracts. A further investigation is highly recommended to explore the possibility of these five steroids as a potential source of active compounds. GRAPHICAL ABSTRACT

Biosynthesis of silver nanoparticles by endophytic fungus Fusarium porliferutum isolated from Allium Sativum and its antimicrobial effect against multidrug resistant bacteria

Biosynthesis of silver nanoparticles by endophytic fungus Fusarium porliferutum isolated from Allium Sativum and its antimicrobial effect against multidrug resistant bacteria

Plant diversity increases diversity and network complexity rather than alters community assembly processes of leaf-associated fungi in a subtropical forest.

Plant diversity significantly impacts ecosystem processes and functions, yet its influence on the community assembly of leaf fungi remains poorly understood. In this study, we investigated leaf epiphytic and endophytic fungal communities in a Chinese subtropical tree species richness experiment, ranging from 1 to 16 species, using amplicon sequencing to target the internal transcribed spacer 1 region of the rDNA. We found that the community assembly of epiphytic and endophytic fungi was predominantly governed by stochastic processes, with a higher contribution of dispersal limitation on epiphytic than on endophytic fungal communities but a higher contribution of selection on endophytic than on epiphytic fungal communities. The plant-epiphytic fungus interaction network was more complex (e.g., more highly connected and strongly nested but less specialized and modularized) than the plant-endophytic fungus interaction network. Additionally, tree species richness was positively correlated with the network complexity and diversity of epiphytic (α-, β- and γ-diversity) and endophytic (β- and γ-diversity) fungi, but was not associated with the contribution of the stochastic and deterministic processes on the community assembly of epiphytic and endophytic fungi. This study highlights that tree species diversity enhances the diversity and network complexity, rather than alters the ecological processes in community assembly of leaf-associated fungi.

Genomic insights into Aspergillus tamarii TPD11: enhancing polyphyllin production and uncovering potential therapeutic applications.

The excavation and utilization of endophytic fungi from medicinal plants is highly important for the development of new drugs. The endophytic fungus Aspergillus tamarii TPD11, which was isolated and obtained by the authors in the previous stage, can produce a variety of polyphyllins with important potential applications in hemostasis, inflammation and antitumor activities; however, the genomic information of TPD11 is still unknown. In this study, we sequenced and assembled the whole genome of the endophytic fungus A. tamarii TPD11, resolved the genome evolutionary relationships of 24 Aspergillus strains, and phylogenetic analysis of the genomes of 16 strains revealed the evolutionary differences between Aspergillus and Penicillium and the mechanisms of genome expansion and contraction. CAZy annotation analysis revealed that TPD11 obtains nutrients mainly by ingesting starch from the host plant. TPD11 has a biosynthesis-related gene cluster for the synthesis of squalestatin S1, and the silencing of this biosynthesis-related gene cluster might increase the content of polyphyllin. Annotation of 11 UDP-glycosyltransferase genes helps to further reveal the biosynthetic pathway of polyphyllin. In addition, secondary metabolism gene cluster and CAZy analyses confirmed the potential probiotic, insecticidal and antimicrobial activities of TPD11 on host plants. This study reveals the intrinsic mechanism by which endophytic fungi increase the content of polyphyllin, which provides a basis for the synthetic synthesis of the natural product polyphyllin.

Myco-nanotechnological approach to synthesize gold nanoparticles using a fungal endophyte, Penicillium oxalicum, and unravelling its antibacterial activity and anti-breast cancer role via metabolic reprogramming

The present study has been designed to fabricate fungal endophyte-assisted gold nanoparticles (AuNPs) and elucidate their anti-breast cancer potential. The aqueous extract of fungal endophytePenicillium oxalicum(PO), associated with the medicinal plantAmoora rohituka, was used for the fabrication of AuNPs (POAuNPs). Physico-chemical characterization using Ultraviolet-visible spectroscopy, Fourier transform infrared, X-ray diffraction, Dynamic light scattering, Zeta potential, Transmission electron microscopy and Field emission scanning electron microscopy analysis revealed stable, uniform distribution, spherical shape and crystalline nature of POAuNPs with a size range of 3-46 nm. Furthermore, the POAuNPs potentially inhibited the growth of pathogenic bacterial strainsEscherichia coliandStaphylococcus aureus. The synthesized POAuNPs have shown potential antioxidant effects against 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide and nitric oxide (NO) radical scavenging assays with an EC50value of 8.875 ± 0.082, 52.593 ± 2.506 and 43.717 ± 1.449 µg mL-1, respectively. Moreover, the value of EC50for the total antioxidant capacity of POAuNPs was found to be 23.667 ± 1.361 µg mL-1. The cell viability of human breast cancer cells, MDA-MB-231 and MCF-7, was found to be reduced after treatment with POAuNPs, and IC50values were found to be 19.753 ± 0.640 and 35.035 ± 0.439 µg mL-1, respectively. Further,in vitrobiochemical assays revealed that POAuNPs induces metabolic reprogramming in terms of reduced glucose uptake, increased lactate dehydrogenase (LDH) release and, disruption of oxidative balance through depletion of glutathione levels, increased nitric oxide (NO) and lipid peroxidation levels as a possible pathway to suppress human breast cancer cell proliferation. Apoptosis-specific nuclear modulations induced by POAuNPs in human breast cancer cells were validated through 4',6-diamidino-2-phenylindole (DAPI) nuclear staining. The present investigation thus attempts to show the first ever fabrication of AuNPs using an aqueous extract ofP. oxalicumassociated withA. rohituka. The results revealed unique physico-chemical characteristics of mycogenic AuNPs, and screening their effect against breast cancer via metabolic reprogramming and induction of apoptosis thus adds great significance for cancer therapeutics, suggesting further exploration to develop nanotherapeutic drugs.

Identification and Assessment of Secondary Metabolites from Three Fungal Endophytes of Solanum mauritianum Against Public Health Pathogens

Fungal endophytes, symbiotic microorganisms residing within plants, are renowned for producing bioactive secondary metabolites with diverse beneficial properties. We investigated the antimicrobial potential of fungal endophytes isolated from Solanum mauritianum, an invasive weed, against clinically significant bacterial pathogens. Selected fungal endophytes (Penicillium chrysogenum, Fusarium sp., and Paracamarosporium leucadendri) were isolated from the plant’s leaves and fruits. Their crude extracts were tested against various referenced strains, such as Mycobacterium species (M. smegmatis ATCC 607 and M. bovis ATCC 27290), Staphylococcus aureus ATCC 6571, Bacillus subtilis ATCC 11774, Klebsiella species (K. pneumoniae ATCC 10031 and K. oxytoca ATCC 8724), Escherichia coli ATCC 10536, and Pseudomonas aeruginosa ATCC 10145, using the Kirby-Bauer disk diffusion method. Resazurin Microtiter Assay was used for the determination of the minimum inhibitory concentration. The chemical nature of the secondary metabolites in the crude extracts produced by fungal endophytes was evaluated using high-resolution liquid chromatography–mass spectrometry (LC-MS) using water and acetonitrile gradient. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS) was employed for untargeted metabolomics. LC-QTOF-MS/MS identified 63 bioactive compounds across the three endophytes. P. chrysogenum had the highest activity against S. aureus and M. smegmatis (1.15 mg/mL and 0.02 mg/mL, respectively), while P. leucadendri demonstrated moderate activity against M. smegmatis (2.91 mg/mL) and E. coli (1.16 mg/mL). Fusarium sp. exhibited the broadest spectrum of antibacterial activity, with MIC values ranging from 0.03 mg/mL (B. subtilis) to 10 mg/mL (M. smegmatis). P. leucadendri produced 29 metabolites, Fusarium sp. had 23 identified metabolites, and a total of 11 metabolites were identified from P. chrysogenum. The fruits of the plant, accounting for 60%, appeared to be the most abundant in the endophyte diversity when compared to the stems and leaves. This study highlights the potential of fungal endophytes from S. mauritianum as a source of novel bioactive compounds, particularly against multidrug-resistant pathogens, contributing to the ongoing efforts to combat antimicrobial resistance.