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Trichoderma harzianum is a well-known biological control agent (BCA) that shows great potential in controlling many pathogenic fungi. To screen for genes associated with mycoparasitism, we sequenced and analyzed the transcriptome of T. harzianum T4 grown in dual culture with Colletotrichum musae. We analyzed differentially expressed genes (DEGs) of Trichoderma harzianum T4 in three different culture periods: before contact (BC), during contact (C) and after contact (AC). A total of 1453 genes were significantly differentially expressed compared to when T. harzianum T4 was cultured alone. During the three periods of double culture of T. harzianum T4 with C. musae, 74, 516, and 548 genes were up-regulated, respectively, and 11, 315, and 216 genes were down-regulated, respectively. The DEGs were screened using GO and KEGG enrichment analyses combined with differential expression multiples. Six gene categories related to mycoparasitism were screened: (a) pathogen recognition and signal transduction, (b) hydrolases, (c) ribosomal proteins and secreted proteins, (d) multidrug-resistant proteins and transporters, (e) heat shock proteins and detoxification, and (f) oxidative stress and antibiotics-related genes. The expression levels of 24 up-regulated genes during T. harzianum T4’s antagonistic interaction with C. musae were detected via real-time fluorescence quantitative PCR (RT-qPCR). This study provided information on the transcriptional expression of T. harzianum T4 against C. musae. These results may help us to further understand the mechanism of mycoparasitism, which can provide a potential molecular target for improving the biological control capacity of T. harzianum T4. [ABSTRACT FROM AUTHOR]

Trichoderma isolates were inhibited variably in-vitro growth of soil-borne phytopathogen Macrophomina phaseolina (Maubl.) Ashby causes root rot in cotton. The growth inhibition of test-pathogen was found to be higher (90.36%) in T. viride NBAIITv23 followed by T. koningii MTCC796 (85.77%) under dual culture antagonism. The microscopic examination suggested that the antagonists Tv23 and MTCC796 adopted mycoparasitism as a strong mode of action to restrain pathogen growth. However, antagonists T. harzianum NBAIITh1 (77.89%) and T. virens NBAIITvs12 (61.74%) demonstrated strong antibiosis action for growth inhibition of the test pathogen. A significant positive correlation was established between the growth inhibition of M. phaseolina and the release of cell wall degrading enzymes- chitinase (p = 0.001), β-1,3, glucanase (p = 0.01), and protease (p = 0.05) under the influence of pathogen cell wall. The chitinase and β-1,3, glucanase activities were elevated 2.09 and 1.75 folds, respectively, in potent mycoparasitic Tv23 strain influenced by a pathogen cell wall compared to glucose as a carbon source. The three unique DNA-RAPD fragments OPA-07(1033), OPA-16(983), and OPO-15(239), amplified by potent mycoparasitic Tv23 strain, were subjected to DNA sequencing and derived functional 864 bp from OPA-16(983) and have sequence homology to ech42 gene with partial CDs of 262 amino acids (nucleotide accession No. KF723016.1 and protein accession No.AHF57046.1). Novel SCAR markers were developed from a functional sequence of OPA-16 fragments and validated across the genomic DNA of eleven Trichoderma antagonists. The novel SCAR markers evolved from the RAPD-SCAR interface to authenticate chitinolytic Trichoderma associated with mycoparasitic action for eco-friendly biocontrol activity. [ABSTRACT FROM AUTHOR]

This study aimed to identify four isolates of Trichoderma sp. (Ufra.T06, Ufra.T09, Ufra.T12, and Ufra.T52) and characterize their interaction with Magnaporthe oryzae in vitro and in vivo conditions. The four isolates of Trichoderma sp. were sequenced, investigated as an antagonist against M. oryzae in five Petri plate assays, and as an inhibitor of conidial germination appressoria formation. Finally, were quantified the lytic activity of chitinase (CHI), glucanase (GLU), and protease (PRO) during co-cultivation of Trichoderma sp. and M. oryzae. In vivo, leaf blast suppression was evaluated in two assays: simultaneous and curative application. Both in vitro and in vivo assays were scanned by electron microscopy (SEM). All isolates were identified as Trichoderma asperellum. All in vitro Petri plates assays reduced M. oryzae colony growth (paired–91.18% by Ufra.T09, volatile metabolites—all isolates equally reduced, non-volatile—68.33% by Ufra.T06, thermostability—99.77% by Ufra.T52 and co-cultivate—64.25% by Ufra.T52). The filtrates and conidia suspensions for T. asperellum isolates inhibited the conidia germination and appressoria formation significantly. In co-cultivate (mycelial or cell wall), all enzymes (GLU, CHI, and PRO) and times (24, 48, and 72 h) showed increased activity. In vivo, reduced leaf blast severity until 94.64% (Ufra.T52cs) in a simultaneous and until 85% (Ufra.T09 24 and 48 hasi) in a curative application. T. asperellum isolates showed efficient control of M. oryzae by mycoparasitism, and antibiosis mechanisms were interfered with by the M. oryzae infection process. [ABSTRACT FROM AUTHOR]

Sphaerodes mycoparasitica, a biotrophic mycoparasite of Fusarium species, improved wheat seed germination and seedling growth in vitro compared to Trichoderma harzianum, a necrotrophic mycoparasite. However, under phytotron conditions, both S. mycoparasitica and T. harzianum had positive impact on wheat seedlings growth in the presence of F. graminearum. Once exposed to the mycoparasites, the DNA quantity of F. graminearum in wheat root decreased. Observed shifts in DNA quantity using qPCR, a set of newly designed Sphaerodes-specific SmyITS primers, as well as Trichoderma-TGP4 and Fusarium-Fg16 N primers, demonstrated the mycoparasite's biocontrol effectiveness in planta. In the presence of F. graminearum, the concentration of S. mycoparasitica DNA remained stable in the root, whereas the amount of T. harzianum DNA decreased . The toxicity assays indicated that S. mycoparasitica's mycelia withstand higher concentrations of deoxynivalenol, 3-acetyldeoxynivalenol, and zearalenone mycotoxins than T. harzianum mycelia. This study compares the ability of two fungi to improve the wheat growth, decrease the root colonization of Fusarium, and withstand mycotoxins. [ABSTRACT FROM AUTHOR]

The production of enzymes involved in mycoparasitism by several strains of ectomycorrhizal fungi: Amanita muscaria (16-3), Laccaria laccata (9-12), L. laccata (9-1), Suillus bovinus (15-4), S. bovinus (15-3), S. luteus (14-7) on different substrates such as colloidal chitin, mycelia of Trichoderma harzianum, T. virens and Mucor hiemalis was examined. Chitinases and β-1,3-glucanases were assayed spectrophotometrically by measuring the amount of reducing sugars releasing from suitable substrate by means of Miller’s method. β-glucosidases were determined by measuring the amount of p-nitrophenol released from p-nitrophenyl- β-D-glucopyranoside. It was observed that A. muscaria (16-3) and L. laccata (9-12) biosynthesized the highest activity of enzymes in contrast to the strains of S. bovinus and S. luteus. The mycelium of T. harzianum turned out to be the best substrate for the induction of β-1,3-glucanases and β-glucosidases for both strains of L. laccata, although the difference in the induction of chitinases in the presence of mycelia of different species of Trichoderma was not indicated. [ABSTRACT FROM AUTHOR]

The cell-wall degrading enzymes β-glucanase and chitinase have been suggested to be essential for the mycoparasitic action of Trichoderma species against plant fungal pathogens. For this reason, the production in different carbon sources of extracellular β-1,3-glucanase, β-1,6-glucanase, chitobiase and chitinase was studied in a mycoparasitic strain of Trichoderma harzianum. Maximal β-glucanase specific activities were detected in media supplemented with either pustulan (β-1,6-glucan), nigeran (α-1,3-glucan alternating with α-1,4-glucan), chitin or Saccharomyces cerevisiae or Botrytis cinerea purified cell walls, whereas the highest chitinase specific activity was obtained in medium supplemented with chitin. Furthermore, β-glucanase, chitobiase and chitinase activities showed an increase parallel to increasing concentrations of either pustulan or chitin added to the cultures, although the extent of this increase varied with the different enzymes. The culture filtrates of T. harzianum grown in these carbon sources also showed lytic activity on purified cell walls of S. cerevisiae and B. cinerea. The enzyme synthesis seemed to be repressed by glucose, 8-hydroxyquinoline, which inhibits transcription, or cycloheximide, an inhibitor of protein synthesis. [ABSTRACT FROM AUTHOR]

Infection of the mucoraceous host Cokeromyces recurvatus by Piptocephalis unispora was studied ultrastructurally, using a new technique involving yeast-phase cells of the host to obtain large numbers of infection sites for thin-sectioning. Morphologically, the haustorial apparatus was similar to that of fungi parasitic on higher plants, and comprised an appressorium, a neck region with a collar and a neck ring, and a lobed region surrounded by a sheath matrix enclosed in an extra-haustorial membrane. Penetration of the host by the infection peg probably involved both enzymatic degradation and physical pressure. Reaction of the host to infection is described and the results related to the theory of host infection by haustorial fungal parasites. [ABSTRACT FROM AUTHOR]