Antagonistic Ability Research Articles

Analysis of the complete genome sequence of Paenibacillus sp. lzh-N1 reveals its antagonistic ability

BackgroundPlant diseases caused by pathogenic fungi are devastating. However, commonly used fungicides are harmful to the environment, and some are becoming ineffective due to fungal resistance. Therefore, eco-friendly biological methods to control pathogenic fungi are urgently needed.ResultsIn this study, a strain, Paenibacillus sp. lzh-N1, that could inhibit the growth of the pathogenic fungus Mycosphaerella sentina (Fr) Schrorter was isolated from the rhizosphere soil of pear trees, and the complete genome sequence of the strain was obtained, annotated, and analyzed to reveal the genetic foundation of its antagonistic ability. The entire genome of this strain contained a circular chromosome of 5,641,488 bp with a GC content of 45.50%. The results of species identification show that the strain belongs to the same species as P. polymyxa Sb3-1 and P. polymyxa CJX518. Sixteen secondary metabolic biosynthetic gene clusters were predicted by antiSMASH, including those of the antifungal peptides fusaricidin B and paenilarvins. In addition, biofilm formation-related genes containing two potential gene clusters for cyclic lactone autoinducer, a gene encoding S-ribosylhomocysteine lyase (LuxS), and three genes encoding exopolysaccharide biosynthesis protein were identified.ConclusionsAntifungal peptides and glucanase biosynthesized by Paenibacillus sp. lzh-N1 may be responsible for its antagonistic effect. Moreover, quorum sensing systems may influence the biocontrol activity of this strain directly or indirectly.

In vitro and in vivo biocontrol studies against Botrytis cinerea, the causal agent of grey mould in Hydrangea macrophylla

ABSTRACT Necroses on aerial parts of Hydrangea macrophylla were regularly observed in plant storage chamber at 2°C in Hortensia France company. A total of 34 Botrytis isolates were collected from Hydrangea plants and their environment. To develop biocontrol methods against Botrytis, eight Trichoderma isolates were collected from Hydrangea or the plant soil substrate in the same cold room. Two Trichoderma isolates (E10SM, E014) from this study and one reference isolate (M03) exhibited a high degree of in vitro parasitism against B. cinerea, by comparison with Trichoderma C04 reference isolate (no parasitism). Culture filtrates of isolates E014 and M03 also showed significant in vitro antibiotic properties against B. cinerea growth. A pathosystem H. macrophylla – B. cinerea was set up in the greenhouse, with the inoculation of leaves using mycelial explants selected as the best infection mode. Using this pathosystem, a biocontrol assay showed a significant effect of M03 isolate towards B. cinerea, using Trichoderma conidia applied to leaves 5 h prior pathogen inoculation. After elicitor addition (B. cinerea grinded mycelia) in Trichoderma cultures, antagonistic potentialities of isolate C04 towards the pathogen was highly enhanced, reaching the inhibition level assessed with isolate M03 grown without elicitor. Optimisation of Trichoderma culture filtrates for antagonistic abilities was investigated, and specific cultural conditions were selected for M03 (12 g L−1 PDB, pH 4.2, 22°C, 22 days) and C04 (2.4 g L−1 PDB, pH 6.2, 13°C, 7 days). Overall, our results suggest great properties of several Trichoderma isolates for future development as biocontrol products.

STUDY ON THE ANTAGONISTIC ACTIVITY AGAINST TWO PATHOGENIC BACTERIA IN HUMANS OF STREPTOMYCES MIP_L26 ISOLATED FROM SOIL IN THE ROOT ZONE OF THE MAY CHANG TREE (LITSEA CUBEB)

Purpose: Study on the antagonistic activity against two pathogenic bacteria in humans (Staphylococcus aureus and Streptococcus pneumoniae) of the Streptomyces MIP_L26 (Called MIP_L26), isolated from the soil in the root zone of the May Chang tree; to investigate the biological characteristics of MIP_L26 Subjects and methods: Experimental study, determine the antimicrobial activity against two pathogenic bacteria in humans (Staphylococcus aureus and Streptococcus pneumoniae), and some biological characteristics of MIP_L26. Results: MIP_L26 was identified as having a strong antagonistic ability against the two bacteria causing Staphylococcus aureus and Streptococcus pneumoniae with an antibacterial ring diameter of 18 ± 5 mm and 13 ± 5 mm, respectively. Based on classification according to morphological, physiological, and biochemical characteristics, combined with the results of 16S rRNA gene sequencing, MIP_L26 was identified as Streptomyces gancidicus MIP_L26. The fermentation medium for the biosynthesis of antibacterial substances was ISP6 and the recovery time for antimicrobial substances was after 72 hours of fermentation.

Potensi Fungi Rizosfer Tanaman Damar (Agathis dammara) Sebagai Agensia Biokontrol Fusarium oxysporum

Plant diseases become one of the dangerous threats to agriculture. Fusarium oxysporum is one of pathogen that attack many agricultural plants. The spread of plant pathogens must be controlled. One of the way to control plant pathogens is to use biological control methods by utilizing biocontrol agents using antagonistic fungi to control F. oxysporum. Antagonistic fungi can be found in various habitats such as rhizosphere soil that contains a lot of exudate released by the roots so that the area is rich in organic compounds. Sampling was carried out in the rhizosphere soil of Damar plants from the Baturraden Botanical Garden. Research on antagonistic fungi from the plant rhizosphere needs further exploration. Therefore, this study was conducted to obtain isolates of rhizosphere fungi that have potential as antagonists against F. oxysporum. This research was carried out with method stages ranging from sampling, isolation, characterization and identification to antagonism tests. The isolation results stated that five different fungi were found from the rhizosphere of the Damar plant. The fungi found were then tested for antagonistic ability against F. oxysporum and it was found that R5 isolate had the best ability to inhibit the growth of F. oxysporum with an inhibitory percentage value of 72.06%. This ability can be new information to be able to develop further about the potential of large plant rhizosphere fungi in their inhibition against plant pathogens.

Biological Control Effect of Antagonistic Bacteria on Potato Black Scurf Disease Caused by Rhizoctonia solani

Potato black scurf, caused by Rhizoctonia solani, is a severe soil-borne disease that affects the quality and production of potatoes worldwide. In our study, we used Paenibacillus polymyxa YF and Bacillus amyloliquefaciens HT to determine the antagonistic ability of R. solani, with a particular focus on the antagonistic action of P. polymyxa YF to R. solani and its biocontrol effect on potato black scurf. In fermentation, filtrate assay, 50% filtrate of P. polymyxa YF and B. amyloliquefaciens HT inhibited the growth of R. solani by 85.55% and 82.86%, respectively. Microscopic observations showed notable morphological changes with mycelial collapse, atrophy, and deformation following treatment with the antagonistic filtrates. Moreover, cell membrane permeability results showed increased conductivity in bacteria-treated samples compared to the control. P. polymyxa YF exhibited stable colonization on potato plants and secreted various extracellular enzymes (protease, amylase, and cellulase), along with the synthetic substances with growth-promoting effects, such as siderophores and Indole-3-acetic acid (IAA). Whether it is in the excised tissue inoculation or potted experiment, the negative control showed the highest rank of disease symptoms. In the pot experiment, after YF treatment, physiological parameters showed remarkable changes in plant height, root length, stem thickness, and dry and fresh weight. Compared to blank control, the activities of the four resistant enzymes increased significantly in the P. polymyxa YF treatment group. The upregulation in the P. polymyxa YF group was 4.04, 0.54, 0.46, and 3.10 times, respectively. PCR analysis identified genes in both bacterial strains coding for antimicrobial lipopeptides, including fenB, ituC, and srfAA, which are associated with fengycin, iturin, and surfactin synthesis. These findings demonstrated that P. polymyxa YF has a prominent antagonistic effect on R. solani, suggesting its potential as an effective biological control agent for controlling potato black scurf.

Test antagonism of several Trichoderma species in suppressing the growth of Alternaria sp. in vitro

Alternaria sp. is a pathogenic fungus that causes purple blotch disease in onion plants. Losses from this disease lead to a decrease in yield by more than 70% and seed damage to 100%. For this reason, a study was conducted to test the antagonistic ability of several Trichoderma species in suppressing the growth of Alternaria sp. in-vitro as an alternative to plant disease control that is safer and more environmentally friendly. Alternaria sp. isolate. derived from onion plants located in Bale Atu, Bukit District, Bener Meriah Regency, Aceh Province. The Trichoderma species used are T. asperellum, T. harzianum, T. virens, and Trichoderma sp. Antagonism testing was carried out using a dual culture method in a 9 cm diameter petri dish. The results showed that, T. asperellum, T. harzianum, T. virens, and Trichoderma sp. able to suppress the growth of Alternaria sp. on observation of 5 HSI. The antagonistic mechanism that occurs is competition against space, nutrition, antibiosis and mycoparasites. The best percentage of resistance occurred in the treatment of T. virens, which was 77.78%. next followed by the inhibitory power of Trichoderma sp. by 72.39%, T. harzianum by 64.80%, and T. asperellum by 60.77%.

Improvement in Biocontrol Ability of Trichoderma Through Chemical Mutation and Gamma Irradiation for The Control of Soil Borne Pathogens

Biocontrol agent like Trichoderma viride was acclaimed as effective, eco-friendly and cheap, nullifying the ill effect of chemicals, These biocontrol agents are identified to act against on array of important soil borne plant pathogens viz.,Sclerotium rolfsii, Rhizoctonia bataticola and Fusarium oxysporum f. sp. ciceri etc.” Improvement in biocontrol ability of Trichoderma viride through mutation” was carried at Department of Plant Pathology, during 2019-2020. The antagonistic ability of a biocontrol agent was determined by its physiological state so that change in physiological or genetically conditions could alter the antagonism. Hence the genetic modification using mutagenesis offers the potential for producing improved bio-protection is likely to enhance their biocontrol capabilities against soil borne pathogen. Mutagenesis by chemical i.e. Ethyl Methyl Sulphonate (EMS) @ 100, 150, 200 and 250 µl/ml and time interval at 30, 45 and 60 minutes. The influence of gamma irradiation on improving production of antifungal metabolites and biological proficiency of the biocontrol agent against soil borne pathogen. Trichoderma viride were irradiated in different dose of gamma radiation (cobalt-60) @ 0, 20, 30, 40 and 50 k-rad. for induced mutation. Sixteen Trichoderma viride mutants were obtained after chemical mutagenesis and gamma irradiation and tested for their antagonistic activities in vitro. Morphological character of efficient mutants was tested up to six generation to check their stability. Among these, four stable mutants viz., TVME 2b, TVME 2c, TVME 3c and TVGM1 were proved as effective antagonists against Sclerotium rolfsii, Rhizoctonia bataticola and Fusarium oxysporum f.sp. ciceri basis of their maximum bioefficiency. Mutants TVME2b, TVME2c, TVME3c and TVGM1 exhibited the highest inhibition to mycelial growth of Sclerotium rolfsii with an inhibition percentage 64.76, 64.22, 63.08 and 62.93% respectively. Rhizoctonia bataticola was inhibited to the extent of 63.47, 60.87, 61.93 and 61.02% by relative mutants, while Fusarium oxysporum f. sp. ciceri was restricted and recorded 63.50, 62.88, 62.03 and 60.74% respectively. The highest chitinase enzyme units/mg of protein i.e. 0.64, 0.63, 0.63 and 0.62 was exerted in TVME2b, TVME2c, TVME3c and TVGM1 having respectively. However, TVME1c contains 0.37 enzyme units; it showed maximum ability against pathogens. hence present study proved that mutagenesis is the efficient tool for improving bioefficiency of Trichoderma viride, a biocontrol agent.

Antimicrobial Activity of Nanozirconium Oxide.

The goal behind this work is to prepare, characterize, and study the antimicrobial behavior of zirconia (ZrO2) nanoparticles (NPs). Various techniques, such as X-ray diffraction (XRD), were used for studying the mineralogical structure and crystal size. The microstructure and chemical composition of the prepared particles were analyzed using a scanning electron microscope attached with an energy-dispersive X-ray analysis (EDAX) unit. The antagonistic ability against several Gram-negative and Gram-positive bacteria, including Salmonella paratyphi, Pseudomonas aeruginosa, Alcaligenes aquatilis, Escherichia coli, Streptococcus pneumoniae, and Staphylococcus aureus, was assessed using the well diffusion method. The results of XRD and scanning electron microscopy (SEM) analyses revealed that the prepared material exhibited the phase of zirconium nanoparticles with particle sizes ranging between 40 and 75 nm. The antimicrobial test results demonstrated that the inhibitory effect increased with the increase of concentration. The inhibitory effect was more pronounced against Gram-positive bacteria, as indicated by the larger size of the inhibitory zone. At a 9% dimethyl sulfoxide (DMSO) concentration, the inhibitory zone had a diameter of 3.50 mm for S. aureus compared to a diameter of 3.40 mm for S. pneumoniae. The use of zirconium oxide nanoparticles reduced the diameter of the inhibitory zone when tested against S. aureus at a 3% DMSO concentration (0.50 mm diameter) and against S. pneumoniae (0.40 mm diameter). Zirconia nanoparticles were also evaluated for their antifungal activity against several species, including Aspergillus niger, Aspergillus flavus, and Penicillium sp. The size of the inhibitory zone indicated the susceptibility of microorganisms to nanozirconium oxide, resulting in a stronger inhibition of Penicillium sp. at a 100% DMSO concentration (4.50 mm diameter) compared to A. niger and A. flavus (3.00 mm diameter). The results for Penicillium sp. at a 3% DMSO concentration showed a diameter of the inhibitory zone of 0.90 mm, while for A. niger and A. flavus, the diameter was 0.80 mm. Thus, our findings demonstrate that the zirconium oxide nanoparticles possess the capability to reduce the inhibition zone effectively for both bacterial and fungal activities.

Toxic effect of nicotine on sperm Morphology in adult male albino rats: Protective potential of Thymus vulgaris Aqueous Extract

Smoking is one of the most problems that cause oxidative stress and affect the health of humans. That affected Fertility in males which nicotine has a toxic effect on spermatogenesis. Thyme extract is shown to have some beneficial effects such as antioxidant properties. Thus, this study aimed to evaluate the antagonistic ability of thyme extract against the toxic effect of the nicotine on epididymal sperm defects in male adult rats, there were divided into four groups;G1: normal saline, G 2: 0.6mg/kg nicotine, G 3: 0.5g/kg thyme extract, G4: 0.6 mg/kg nicotine and 0.5g/kg thyme extract, Treatments lasted for 28 days. Sperms morphology was assessed for fertility. It was significantly (P<0.05) increased in the nicotine-treated group, compared with control (P<0.05). However, co-administration of nicotine with thyme extract significantly decreased the values of sperm defects as compared to that observed in nicotine group (P<0.05). The findings suggest that the thyme extract possibly ameliorates the deleterious effects of nicotine on some reproductive indices in male albino rats.

Wheat Rhizosphere-Derived Bacteria Protect Soybean from Soilborne Diseases.

Soybean (Glycine max [L.] Merr.) is an important oilseed crop with a high economic value. However, three damaging soybean diseases, soybean cyst nematode (SCN; Heterodera glycines Ichinohe), Sclerotinia stem rot caused by the fungus Sclerotinia sclerotiorum (Lid.) de Bary, and soybean root rot caused by Fusarium spp., are major constraints to soybean production in the Great Plains. Current disease management options, including resistant or tolerant varieties, fungicides, nematicides, and agricultural practices (crop rotation and tillage), have limited efficacy for these pathogens or have adverse effects on the ecosystem. Microbes with antagonistic activity are a promising option to control soybean diseases with the advantage of being environmentally friendly and sustainable. In this study, 61 bacterial strains isolated from wheat rhizospheres were used to examine their antagonistic abilities against three soybean pathogens. Six bacterial strains significantly inhibited the growth of Fusarium graminearum in the dual-culture assay. These bacterial strains were identified as Chryseobacterium ginsengisoli, C. indologenes, Pseudomonas poae, two Pseudomonas spp., and Delftia acidovorans by 16S rRNA gene sequencing. Moreover, C. ginsengisoli, C. indologenes, and P. poae significantly increased the mortality of SCN second-stage juveniles (J2), and two Pseudomonas spp. inhibited the growth of S. sclerotiorum in vitro. Further growth chamber tests found that C. ginsengisoli and C. indologenes reduced soybean Fusarium root rot disease. C. ginsengisoli and P. poae dramatically decreased SCN egg number on SCN-susceptible soybean 'Williams 82'. Two Pseudomonas spp. protected soybean plants from leaf damage and collapse after being infected by S. sclerotiorum. These bacteria exhibit versatile antagonistic potential. This work lays the foundation for further research on the field control of soybean pathogens.

Evaluation of the Efficacy of Trichoderma species and their Fungal Toxins in the Eradication of Alternaria alternata Causing Seeds Decay and Damping-off Disease on Cotton in Iraq

This study aimed to isolate and identify the pathogens accompanying the rotting and death of cotton seeds and seedlings. Also, some Trichoderma spp. were assessed against the fungal pathogen associated with the disease. The results showed that one of the essential isolated fungi, Alternaria alternata, has demonstrated high virulence in attacking cotton seeds and seedlings and reducing germination and growth. This fungus was identified based on its morphological and molecular characteristics. The Trichoderma species applied have shown high efficiency in reducing infection rates and increasing cotton germination percentage. Every isolate of Trichoderma showed a high efficiency against the fungus A. alternata by providing the highest antagonistic ability, reaching 93.75%. The highest percentage of inhibition growth of the pathogen (86.11%) was achieved by Trichoderma koningiopsis, while the lowest percentage of inhibition growth of the pathogen was 66.65 % for Trichoderma reesei. However, the biological formula prepared from species Trichoderma viride, Trichoderma pseudokoningii, Trichoderma koningiopsis and Trichoderma reesei displayed the highest percentage of inhibition of 100% against the fungus A. alternata. Keywords. Alternaria alternata; Trichoderma spp.; Trichodermin; gliotoxin; Biological control.

Molecular Identification of Endophytic Fungi from Javanese Ginseng (Talinum paniculatum Gaertn.) and their Potential against Phytopathogens

Endophytes from medicinal plants have been demonstrated to produce bioactive chemicals with antibacterial capabilities. Previous research found many endophytes in Javanese ginseng roots. Identifying and comprehending the benefits of endophyte microorganisms is critical for boosting plant growth and defense. The aim of this study was to identify endophytic microbes from Javanese ginseng with antifungal activity. In this present study, two isolates the GJ-9 and FN-1, were analyzed using NL1/NL4 and ITS1/4 primers. The amplification and sequencing of the ITS and the D1-D2 LSU rRNA gene were performed. The D1-D2 LSU rRNA sequence analysis results showed that GJ-9 has similarities with Candida Spencermartinsiae with 99.82% percentage identity, while FN-1 has been identified as Aspergillus flavus according to the ITS sequence analysis result with 99.83% percentage identity. Antagonistic assays showed both isolates displayed considerable antagonistic ability against Rhizopus stolonifera, Pythium sp., Botrytis sp., and Fusarium sp, with overall inhibition rate were over 50%. The Aspergillus flavus showed the better ability to inhibit the growth of Phytium sp. (74.90 %) and Rhizopus stolonifera (60 %), while the Candida Spencermartinsiae is better for controlling Botrytis sp. (55.68%) and Fusarium sp. (60.39 %). The result suggests the endophyte from Javanese ginseng can be used as an agent for controlling various plant diseases; furthermore, it could lead to a reduction of agrochemical inputs.

Biocontrol fungi induced stem-base rot disease resistance of Morinda officinalis How revealed by transcriptome analysis.

Morinda officinalis How (MO) is a Rubiaceae plant, and its medicinal part is dried root, which is one of the "Four Southern Medicines" in China. At present, the plant MO breed seedlings mainly by cutting methods. Long-term asexual propagation makes pathogenic fungi accumulate in MO, leading to stem-base rot, which is caused by Fusarium oxysporum (Fon). In this study, we used Trichoderma harzianum and Pestalotiopsis sp. as biocontrol fungi to investigate their antagonistic ability to Fon through in vitro antagonism and pot experiments, and combined with transcriptome sequencing to explore the mechanism of biocontrol. The results showed that both Trichoderma harzianum and Pestalotiopsis sp. could inhibit the growth of Fon. In addition, Trichoderma harzianum and Pestalotiopsis sp. could also enhance the basic immunity to Fon by increasing the activities of defensive enzymes such as POD and SOD, chlorophyll content, soluble sugar content, and oligosaccharide content of MO. The mechanism of biological control of stem-base rot of MO was discussed by transcriptome technology. MO was treated with two treatments, root irrigation with biocontrol fungi or inoculation with Fon after root irrigation with biocontrol fungi. Transcriptome sequencing revealed that nearly 11,188 differentially expressed genes (DEGs) were involved in the process of inducing MO systemic resistance to Fon by biocontrol fungi. Meanwhile, Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, as well as transcription factor (TFs) prediction showed that there were significant differences in the expression levels of MO roots under different treatments. Also, the genes of the "MAPK signaling pathway" and "plant hormone signaling pathway" were analyzed, in which the ERFs gene of the ethylene signal transduction pathway participated in the metabolism of glycosyl compounds. It is speculated that the ethylene signal may participate in the immune response of the sugar signal to the infection of Fon. After qRT-PCR verification of 10 DEGs related to the ethylene signal transduction pathway, the expression trend is consistent with the results of transcriptome sequencing, which proves the reliability of transcriptome sequencing. In conclusion, this study preliminarily identified the molecular mechanism of the biological control of MO stem-base rot and provided a scientific basis for further research on the prevention and control mechanism of MO stem-base rot.

Effect of Some Bio-agents and Naphthalene Acetic Acid to Inhabit Fusarium Nygamai Isolated from Hibiscus Sabdarriffa

A laboratory experiment was carried out according to the randomized complete design (RCD) during the season of 2022- 2023 to study the effect of Trichoderma harzainum, Bacillus subtilis and Naphthalene acetic acid. The results showed that the biological agent T. harizanium achieved an antagonistic ability against F. nygamia amounted 1.25 according to the Bell scale, the concentration 300 mg/l of NAA led to inhibiting of F. nygamia 100%, compared to the control treatment 0%, in comparison, the concentrations 300mg/L of NAA did not cause any inhibitory effect on T. harizanum 0%, the Uniform fungicide at concentrations (100-900) mg/L caused inhibition of F. nygamia, which reached 24.82, 57.78, 89.26 and 100% respectively compared to the control treatment 0%.

In Vitro Studies of Endophytic Bacteria Isolated from Ginger (Zingiber officinale) as Potential Plant-Growth-Promoting and Biocontrol Agents against Botrytis cinerea and Colletotrichum acutatum

Agriculture currently confronts a multitude of challenges arising from the excessive utilization of chemical pesticides and the proliferation of phytopathogenic fungi strains that exhibit resistance to commonly employed active compounds in the field. Botrytis cinerea and Colletotrichum acutatum are phytopathogenic fungi that inflict substantial economic losses within agriculture and food due to their high impacts on crops both pre- and post-harvest. Furthermore, the emergence of fungal strains that are resistant to commercial fungicides has exacerbated this problem. To explore more environmentally sustainable alternatives for the control of these pathogens, an investigation into the endophytic bacteria associated with ginger (Zingiber officinale Rosc.) was conducted. The primary focus of this study involved evaluating their inhibitory efficacy against the fungi and assessing their potential for promoting plant growth. The endophytic bacteria genera Lelliottia, Lysinibacillus, Kocuria, Agrococcus, Acinetobacter, Agrobacterium, Zymobacter, and Mycolicibacterium were identified. All isolates showed remarkable in vitro antagonistic ability against B. cinerea (>94%) and C. acutatum (>74%). Notably, the Lelliottia amnigena J29 strain exhibited a notable proficiency in producing extracellular enzymes and indole compounds (IAA), solubilizing phosphate and potassium, and forming biofilm. Furthermore, the Lysinibacillus capsici J26, Agrococcus citreus J28, and Mycolicibacterium sp. J5 strains displayed the capacity for atmospheric nitrogen fixation and siderophore production. These findings underscore the agricultural and biotechnological potential of endophytic bacteria derived from ginger plants and suggest the feasibility of developing alternative approaches to manage these two phytopathogenic fungi.

Inhibition of Acetylcholinesterase with Novel 1, 3, 4, Oxadiazole Derivatives: A Kinetic, In Silico, and In Vitro Approach.

Alzheimer's disease (AD) is a neurological disease that disturbs the memory, thinking skills, and behavior of the affected person. AD is a complex disease caused by the breakdown of acetylcholine via acetylcholinesterase (AChE). The present study aimed to assess the synthetic inhibitors of AChE that could be used to treat AD. For this purpose, synthetic compounds of oxadiazole derivatives (15-35) were evaluated and identified as promising inhibitors of AChE, exhibiting IC50 varying between 41.87 ± 0.67 and 1580.25 ± 0.7 μM. The kinetic parameters indicated that all the studied compounds bind to the allosteric site and decrease the efficiency of the AChE enzyme. In silico docking analysis showed that the majority of the compounds interact with the anionic subsite and Per-Arnt-Sim domain of AChE and are stabilized by various bonds including π-π and hydrogen bonding. The stability of the most potent compounds 16 and 17 with AChE interaction was confirmed by molecular dynamics simulations. Moreover, all compounds exhibited concentration-dependent calcium (Ca2+) antagonistic and spasmolytic activities. Among the whole series of oxadiazole derivatives, compounds 16 and 17 displayed the highest activities on spontaneous and potassium (K+)-induced contraction. Therefore, the AChE inhibitory potential, cytotoxicity safe profile, and Ca2+ antagonistic ability of these compounds make them potential therapeutic agents against AD and its associated problems in the future.

Metabolic Features of a Novel Trichoderma asperellum YNQJ1002 with Potent Antagonistic Activity against Fusarium graminearum.

Trichoderma, a well-known and extensively studied fungal genus, has gained significant attention for its remarkable antagonistic abilities against a wide range of plant pathogens. In this study, a total of 108 Trichoderma isolates were screened through in vitro dual antagonistic assays and culture filtrate inhibition against Fusarium graminearum. Of these, the YNQJ1002 displayed noteworthy inhibitory activities along with thermal stability. To validate the metabolic differences between YNQJ1002 and GZLX3001 (with strong and weak antagonism, respectively), UPLC-TOF-MS/MS mass spectrometry was employed to analyze and compare the metabolite profiles. We identified 12 significantly up-regulated metabolites in YNQJ1002, which include compounds like Trigoneoside, Torvoside, trans,trans-hepta-2,4,6-trienoic acid, and Chamazulene. These metabolites are known for their antimicrobial properties or signaling roles as components of cell membranes. Enriched KEGG analysis revealed a significant enrichment in sphingolipid metabolism and linoleic acid metabolism, as well as autophagy. The results demonstrated that YNQJ1002's abundance of antimicrobial substances, resulting from specific metabolic pathways, enhanced its superior antagonistic activity against F. graminearum. Finally, YNQJ1002 was identified using the ITS, tef1-1α, and rpb2 regions, with MIST system sequence matching confirming its classification within the species. Overall, we have obtained a novel strain, T. asperellum YNQJ1002, which is rich in metabolites and shows potential antagonistic activity against F. graminearum. This study has opened promising prospects for the development of innovative Trichoderma-derived antifungal compounds, featuring a unique mechanism against pathogens.

Characterization of Trichoderma strains for novel species-specific markers by multiplex PCR and antagonistic property against Alternaria ricini in castor (Ricinus communis L.)

The study aimed at characterizing six Trichoderma strains isolated from the rhizospheric soil of castor growing region of Telangana, India. Microscopic examination and sequencing of ribosomal DNA (rDNA) using internal transcribed spacer (ITS) and D1-D2 region-specific primers revealed them as members of Trichoderma sp. Whereas the phylogenetic analysis revealed four of those strains as Trichoderma asperellum, two strains were confirmed as Trichoderma harzianum with a high sequence similarity of >99%. Further, multiplex PCR results with Trichoderma-specific primers; TEF1 (translation elongation factor 1) and rpb2 (the second largest subunit of RNA polymerase II) gene-specific primers confirmed the findings resulting from the phylogenetic analysis. To develop a set of sequence characterized amplified region (SCAR) markers, these strains were screened with 185 random amplified polymorphic DNA (RAPD) primers. A pairwise comparison of correlation of coefficient values determined from the RAPD-based genetic similarity analysis revealed that TV3 and TS4 strains were closely related to each other (0.98) confirming them as T. harzianum while N13, 7316, TV5, and TV2B16 strains formed a different cluster with T. asperellum strains. A set of novel SCAR markers were developed to distinguish these two species, T. asperellum and T. harzianum including the reported Trichoderma strains as Ex-type strains. T. harzianum strains had extremely low sporulation ability to be tested for biocontrol properties. Of the four T. asperellum strains, 7316 followed by N13 demonstrated high antagonistic ability against the fungal pathogen, Alternaria ricini indicating these strains as potential biocontrol agents to limit Alternaria infection in castor.

Suppression of Phytophthora capsici in Chile Pepper Using Brassica juncea and Hordeum vulgare Cover Crop Residues and Trichoderma harzianum as a Biocontrol Agent.

Phytophthora blight, caused by Phytophthora capsici, is a serious disease of many vegetable crops worldwide. In New Mexico, U.S.A., the disease affects chile pepper (Capsicum annuum L.), a major crop in the state. There is no single tool that effectively controls the disease. Continuous research is needed in identifying combination of tools that can reduce the impact of Phytophthora blight. We explored the potential of combining cover crops and biocontrol agents to reduce soilborne diseases. This study aimed to evaluate the effects of Indian mustard (Brassica juncea L.) cover crop on the antagonistic ability of Trichoderma harzianum against P. capsici in vitro and to quantify the impacts of combining soil amendment with residues from B. juncea and barley (Hordeum vulgare L.) cover crops and plastic covering on infection of chile pepper seedlings by P. capsici under greenhouse conditions. Volatiles from macerated tissue of B. juncea significantly reduced P. capsici and T. harzianum growth in the absence of soil by 89.0 and 79.0%, respectively. When incorporated in soils, volatiles from macerated tissue of B. juncea significantly reduced P. capsici and T. harzianum by 33.4 and 7.8%, respectively. T. harzianum was more resilient to B. juncea biofumigation than P. capsici. Significant reduction in disease incidence was observed with B. juncea-fumigated soil, while no disease suppression was observed with soil incorporation of H. vulgare residues. Covering soil with plastic was necessary for increasing the efficacy of B. juncea biofumigation.

Contribute to Know the Enzymes that Secreted by Trichoderma viride and its Spores Loaded by Alginic Acid on Cucumber Seeds

Trichoderma species are utilized as a biological fungicide in agriculture due to their great antagonistic ability. Additionally, they can increase nutrient uptake, fertility, stress resistance, and plant development. They are also opportunistic and symbiotic infections, which may cause plant defense systems to become active. There is a need to reveal the molecular underpinnings of the disease resistance that Trichoderma induces despite research documenting its biocontrol effectiveness against fungal diseases. Therefore, the objective of the current investigation was to identify the fungus-secreted enzymes and its spores loaded by alginic acid on cucumber seeds