BACKGROUND: This study explores the potential of the endophytic fungus Aureobasidium pullulans AKW for melanin production and its anticancer activity.
METHODS: We report a significant achievement: A. pullulans AKW synthesized 4.89 g/l of melanin in a simple fermentation medium devoid of tyrosine, a precursor typically required for melanin biosynthesis. This suggests a potentially novel pathway for melanin production compared to previous studies relying on complex media and tyrosine. Furthermore, the isolated and characterized melanin exhibited promising selectivity as an anti-cancer agent. It triggered apoptosis in A431 cancer cells, demonstrating some selectivity compared to normal cells. This selectivity was confirmed by IC50 values and further supported by gene expression changes in A431 cells. Melanin treatment downregulated the anti-apoptotic Bcl2 gene while upregulating pro-apoptotic Bax and p53 genes, indicating its ability to induce programmed cell death in cancer cells.
RESULTS: Our results demonstrate that A. pullulans AKW-derived melanin exhibits cytotoxic effects against A431, HEPG2, and MCF7 cell lines. Interestingly, the present fungal strain synthesized melanin in a simple medium without requiring precursors.
CONCLUSIONS: The selective activity of the current melanin towards cancer cells, its ability to induce apoptosis, and its relatively low toxicity towards normal cells warrant further investigation for its development as a novel therapeutic option.

This study investigated the potential of endophytic fungi to produce paclitaxel (Taxol®), a potent anticancer compound widely employed in chemotherapy. This research aimed to identify, confirm, and characterize endophytic fungi capable of paclitaxel (PTX) production and assess their paclitaxel yield. Additionally, it aimed to investigate factors influencing paclitaxel production. A total of 100 endophytic fungal isolates were collected and identified from the roots of Artemisia judaica. Aspergillus fumigatiaffinis exhibited the highest PTX production (26.373 μg L-1) among the isolated endophytic fungi. The strain was identified as A. fumigatiaffinis (Accession No. PP235788.1). Molecular identification confirmed its novelty, representing the first report of PTX production by A. fumigatiaffinis, an endophyte of Artemisia judaica. Optimization through full factorial design of experiments (DOE) and response surface methodology (RSM) significantly enhanced PTX production to 110.23 μg L-1 from 1 g of dry weight of the fungal culture under optimal conditions of pH 8.0, 150 μg L-1 becozyme supplementation, and 18 days of fermentation in potato dextrose broth. The presence of paclitaxel was confirmed using thin layer chromatography, high performance liquid chromatography, and gas chromatography-mass spectrometry. These findings maximize the role of endophytic fungus to produce a secondary metabolite that might be able to replace the chemically produced PTX and gives an opportunity to provide a sustainable source of PTX eco-friendly at high concentrations. KEY POINTS: • Endophytic fungi, like A. fumigatiaffinis, show promise for eco-friendly paclitaxel production • Optimization strategies boost paclitaxel yield significantly, reaching 110.23 μg L -1 • Molecular identification confirms novelty, offering a sustainable PTX source.

This study analyzed flower bud differentiation and fruiting stages to investigate how the structure of the plant endophytic microbial community in the roots of tomatoes changes with plant senescence. Based on high-throughput sequencing technology, the diversity and relative abundance of endophytic microorganisms (bacteria and fungi) in tomato stems at different growth stages were analyzed. At the same time, based on LEfSe analysis, the differences in endophytic microorganisms in tomato stems at different growth stages were studied. Based on PICRUSt2 function prediction and FUNGuild, we predicted the functions of endophytic bacterial and fungal communities in tomato stems at different growth stages to explore potential microbial functional traits. The results demonstrated that not only different unique bacterial genera but also unique fungal genera could be found colonizing tomato roots at different growth stages. In tomato seedlings, flower bud differentiation, and fruiting stages, the functions of colonizing endophytes in tomato roots could primarily contribute to the promotion of plant growth, stress resistance, and improvement in nutrient cycling, respectively. These results also suggest that different functional endophytes colonize tomato roots at different growth stages.

Endophytes play important roles in potato production. The whole genome of endophytic Micrococcus sp. Strain HOU01, isolated from potato root grown at Vietnam National University of Agriculture, Hanoi, Vietnam, was sequenced using Oxford Nanopore\'s PromethION platform. The complete circular genome is 2,552,707 bp with a GC content of 72.5%.

This study investigated the effects of the antidepressant sertraline hydrochloride (Ser-HCI) on rice physiology when combined with arsenic (III) or cadmium. Hydroponic experiments revealed that combined lower concentrations (0.2 and 0.6 mg L-1) of Ser-HCl and As (III) or Cd increased rice biomass and reduced pH and low molecular weight organic acids. The fluorescence intensity was enhanced with Ser-HCl and As-only treatments, with a significant difference (p < 0.05) in the dissolved organic matter index. There was a decrease in endophyte-specific operational taxonomic units, with proteobacteria dominating the rice root endophytes. The addition of Ser-HCl resulted in the Verrucomicrobiota increasing by 6.4 times, which was positively correlated with malic acid and negatively correlated with pH. Functional annotation highlighted alterations in carbohydrate metabolism pathways. This study provides insights into the interactive effects of Ser-HCl on rice when combined with As (III) or Cd, addressing gaps in our understanding of the impact of antidepressants on plant systems.

Investigating oat tissue microflora during its different developmental stages is necessary for understanding its growth and anti-disease mechanism. In this study, 16S rDNA and ITS (Internally Transcribed Spacer) high-throughput sequencing technology were used to explore the microflora diversity of oat tissue. Twenty-seven samples of leaves, stems, and roots from three developmental stages, namely the seedling stage (SS), jointing stage (JS), and maturity stage (MS), underwent sequencing analysis. The analysis showed that 6480 operational taxonomic units (OTUs) were identified in the examined samples, of which 1698 were fungal and 4782 were bacterial. Furthermore, 126 OTUs were shared by fungi, mainly Ascomycota, Basidiomycota, and Mucoromycota at the phylum level, and 39 OTUs were shared by bacteria, mainly Actinobacteriota and Proteobacteria at the phylum level. The microbial diversity of oat tissue in the three developmental stages showed differences, and the α-diversity of the bacteria and β-diversity of the bacteria and fungi in the roots were higher than those of the stems and leaves. Among the bacteria species, Thiiopseudomonas, Rikenellaceae RC9 gut group, and Brevibacterium were predominant in the leaves, MND1 was predominant in the roots, and Lactobacillus was predominant in the stems. Moreover, Brevibacterium maintained a stable state at all growth stages. In the fungal species, Phomatospora was dominant in the leaves, Kondoa was dominant in the roots, and Pyrenophora was dominant in the stems. All species with a high abundance were related to the growth process of oats and antagonistic bacteria. Furthermore, connection modules were denser in bacterial than in fungal populations. The samples were treated with superoxide dismutase and peroxidase. There were 42 strains associated with SOD (Superoxide dismutase), 60 strains associated with POD (Peroxidase), and 38 strains in total, which much higher than fungi. The network analysis showed that bacteria might have more dense connection modules than fungi, The number of bacterial connections to enzymes were much higher than that of fungi. Furthermore, these results provide a basis for further mechanistic research.

BACKGROUND: Entomopathogenic fungi (EPF) treatment of plants may affect the survival and feeding preferences of herbivorous pests. However, comprehensive studies on the fitness across their entire life cycle, feeding behavior, and physiological changes in herbivores consuming EPF-treated plants within the tripartite interactions of EPF, plants, and pests are still limited. In this study, we utilized life tables, electrical penetration graph (EPG), and metabolomics to uncover the biological and physiological characteristics of Bemisia tabaci on tomato plants inoculated with Beauveria bassiana through root irrigation.
RESULTS: Our study indicated that Beauveria bassiana Bb252 can penetrate the entire tissue from the point of inoculation, primarily colonizing the intercellular spaces and vascular tissue. However, this colonization is temporary, lasting no more than 35 days. Moreover, the population fitness and feeding behavior of Bemisia tabaci on tomato plants treated with Beauveria bassiana via root irrigation were significantly affected, showing a substantial 41.4% decrease in net reproductive rate (R0), a notable reduction in watery salivation, and shortened phloem ingestion. Lastly, we observed a significant decrease in hormones and amino acids of whiteflies that fed on Beauveria bassiana-treated tomato plants by root irrigation.
CONCLUSIONS: Our results indicated that the endophyte, Beauveria bassiana Bb252, reduced demographic fitness of Bemisia tabaci by altering its hormones and amino acids levels. These findings enhance our understanding of multitrophic interactions in integrated pest management. © 2024 Society of Chemical Industry.

Endophytic and rhizospheric microorganisms associated with plants play a crucial role in plant health, pest and disease defense, and fruit yield by actively participating in the plant\'s adaptation to its environment. In this study, high-throughput sequencing technology was employed to analyze the community structure and diversity of endophytic and rhizospheric soil microorganisms in Berchemia polyphylla var. leioclada. The results revealed significant differences in microbial diversity and community structure between the soil and plant compartments within the same geographic region. Microbial diversity and species composition varied among different geographic locations. The dominant bacteria in plants were Cyanobacteria and Proteobacteria, with dominant genera including Methylobacterium-Methylorubrum, Escherichia-Shigella and Sphingomonas. In contrast, the dominant bacteria in soil were Proteobacteria, Acidobacteriota, and Actinobacteriota, with dominant genera such as Sphingomonas, Conexibacter and Vicinamibacteraceae, with Sphingomonas was considered core groups present in all plant and soil samples. As for fungi, the dominant phyla in both plants and soil were Ascomycota, Basidiomycota, and Mortierellomycota, with different dominant genera between the two compartments, including Fusarium, Septoria, and Mortierella, totaling 59 genera. Linear discriminant analysis at the genus level identified 102 bacterial and 54 fungal indicator taxa associated with plants and soil. Co-occurrence network analysis indicated close interactions among soil bacterial microorganisms. Functional prediction of the top 10 microbial genes revealed three bacterial metabolic pathways shared between soil and plants, while the predominant fungal metabolic types were similar between the two compartments but with varying abundances. This study elucidates the diversity and interplay of endophytic and rhizospheric microorganisms in Berchemia polyphylla var. leioclada across diverse geographical regions, providing insights crucial for the plant\'s conservation and development.

UNASSIGNED: Entomopathogenic fungi exists naturally in plants as an asymptote and have the potential to reduce the population of insect pests through indirect interactions. This study was conducted to detect and characterize the endophytic fungi Beauveria bassiana and Metarhizium robertsii from the rhizosphere soil of tomato plants and their virulence effect on Galleria melonella.
UNASSIGNED: From the rhizosphere soil of 40 tomato fields, three Beauveria bassiana and seven Metarhizium robertsii isolates were isolated using the galleria bait method. All fungi isolate were morphologically characterized by their colony color, shape, and surface texture. Isolates with the highest percentages of germination, conidial yield, and radial growth were selected, and their virulence was evaluated on second instar larvae of Galleria melonella under laboratory conditions.
UNASSIGNED: In this study, Beauveria bassiana showed white colony color and aseptate hyphae, whereas Metarhizium robertsii showed dark green to light green colony color and septate hyphal structures. Maximum spore production and conidial length were obtained by Beauveria bassiana isolate APPRC-27 with 2.67x10 7 spores ml -1 and 3.24 µm, respectively. Colony radial growth rates ranged from 1.73 to 3.24 mm day -1. The results revealed that the highest mortality rate of Galleria melonella (100%) was obtained by Metarhizium robertsii isolates K-61 and K-102 at a concentration of 1x10 8 conidial ml -1 at 7 days post-inoculation. The lowest mortality rate was registered by Metarhizium robertsii isolate RST-11.
UNASSIGNED: In the present study, isolates that produced the most spores and had the highest germination rates were the most virulent to Galleria mellonella second instar larvae. Therefore, virulent entomopathogenic fungi, Beauveria bassiana and Metarhizium robertsii, are promising bioagents for the control of insect pests.

An endophytic actinomycete designated TRM65318T, was isolated from the root of Peganum harmala L. Its taxonomic status was determined using a polyphasic approach. Comparative 16S rRNA gene sequence analysis indicated that strain TRM65318T is phylogenetically most closely related to Myceligenerans salitolerans XHU 5031T (98.15 %) and Myceligenerans xiligouense DSM 15700T (97.78 %). The peptidoglycan belonged to type A4α. The polar lipids were phosphatidylinositol, phosphatidylglycerol, diphosphatidylglycerol, two unknown lipids and three glycolipids. The predominant menaquinones were MK-9(H4) and MK-9(H6) and the whole-cell sugars contained glucose, mannose and galactose. Major fatty acids were anteiso-C15 : 0, iso-C15 : 0 and C16 : 0. Strain TRM65318T had a genome size of 5881012 bp with a genome G+C content of 71.79 mol%. The average nucleotide identity and DNA-DNA hybridization values between strain TRM65318T and the most closely related species were much lower than the thresholds commonly used to define species. At the same time, differences in phenotypic and genotypic data showed that strain TRM65318T could be clearly distinguished from M. salitolerans XHU 5031T. Therefore, it is concluded that strain TRM65318T represents a novel species of the genus of Myceligenerans. The proposed name for this organism is Myceligenerans pegani sp. nov., with type strain TRM65318T (=CCTCC AA 2019057T=LMG 31679T).