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Fusarium stalk rot (FSR) caused by Fusarium graminearum (FG) significantly affects the productivity of maize grain crops. Application of agrochemicals to control the disease is harmful to environment. In this regard, use of biocontrol agent (BCA) is an alternative to agrochemicals. Although Trichoderma species are known as BCA, the selection of host-pathogen specific Trichoderma is essential for the successful field application. Hence, we screened a total of 100 Trichoderma isolates against FG, selected Trichoderma harzianum (CCTCC-RW0024) for greenhouse experiments and studied its effect on changes of maize rhizosphere microbiome and biocontrol of FSR. The strain CCTCC-RW0024 displayed high antagonistic activity (96.30%), disease reduction (86.66%), biocontrol-related enzyme and gene expression. The root colonization of the strain was confirmed by eGFP tagging and qRT-PCR analysis. Pyrosequencing revealed that exogenous inoculation of the strain in maize rhizosphere increased the plant growth promoting acidobacteria (18.4%), decreased 66% of FG, and also increased the plant growth. In addition, metabolites of this strain could interact with pathogenicity related transcriptional cofactor FgSWi6, thereby contributing to its inhibition. It is concluded that T. harzianum strain CCTCC-RW0024 is a potential BCA against FSR.

The efficacy of seven strains of Trichoderma asperellum collected from the fields in Southern China was assessed against Fusarium graminearum (FG) the causal agent of corn stalk rot of maize were in vitro for their antagonistic properties followed by statistical model of principal compound analysis to identify the beneficial antagonist T. asperellum strain. The key factors of antagonist activity were attributed to a total of 13 factors including cell wall degrading enzymes (chitnase, protease and b-glucanases), secondary metabolites and peptaibols and these were analyzed from eight strains of Trichoderma. A linear regression model demonstrated that interaction of enzymes and secondary metabolites of T. asperellum strain ZJSX5003 enhanced the antagonist activity against FG. Further, this strain displayed a disease reduction of 71 % in maize plants inoculated with FG compared to negative control. Pointing out that the T. asperellum strain ZJSX5003 is a potential source for the development of a biocontrol agent against corn stalk rot.

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Background: Biogenic silver nanoparticles (AgNPs) have wider range of biomedical applications. The present work synthesized Tp-AgNPs using mycelial extract of endophytic fungus Talaromyces purpureogenus (MEEF), characterized, and analyzed for antibacterial, anti-proliferation and cell wounding healing activities. Methods: The synthesized Tp-AgNPs were characterized by UV-visible spectrophotometer (UV-Vis), field emission transmission electron microscopy (FETEM) with energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), particle size analysis (PSA) and X-ray diffraction (XRD). Further, antibacterial activity was determined by Kirby–Bauer test and anti-proliferation activity was tested in human lung carcinoma A549 by water-soluble tetrazolium and flow cytometer assay. In addition, cell wounding healing activity was determined by scratch assay. Results: UV-Vis results displayed a strong absorption peak from 390 nm to 420 nm, which indicated the successful synthesis of Tp-AgNPs. FETEM-EDS results indicated the round and triangle shaped Tp-AgNPs with the average size of 25 nm in accordance with PSA. FTIR analysis indicated the involvement of various functional molecules from MEEF in the synthesis of Tp-AgNPs. XRD result proved nature of Tp-AgNPs as a high-quality crystal. The Tp-AgNPs significantly inhibited the growth of bacterial pathogens at the minimal inhibitory concentration of 16.12 μg.mL −1 for Gram + , and 13.98 μg.mL −1 for Gram − bacteria. Further, Tp-AgNPs (2 μg.mL −1 ) showed a strong anti-proliferation effect in A549. Interestingly, Tp-AgNPs was not cytotoxic to normal NIH3T3 cells. In addition, the NPs exhibited a strong cell wounding healing activity. Conclusion: This work biosynthesized AgNPs with strong antibacterial, anticancer and cell wound healing properties using endophytic fungus T. purpureogenus .

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