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Trichoderma Species (trichoderma + species)

Distribution by Scientific Domains

Chemistry	55%
Life Sciences	44%

Selected Abstracts

Peptaibiomics: Screening for Polypeptide Antibiotics (Peptaibiotics) from Plant-Protective Trichoderma Species

CHEMISTRY & BIODIVERSITY, Issue 6 2006
Thomas Degenkolb
Abstract Eight strains of Trichoderma species (T. strigosum, T. erinaceus, T. pubescens, T. stromaticum, and T. spirale as well as T. cf. strigosum, T. cf. pubescens) were selected because of their antagonistic potential against Eutypa dieback and Esca which are fungal diseases of grapevine trunks. These isolates were screened for the production of a group of polypeptide antibiotics named peptaibiotics, including its subgroups peptaibols and lipopeptaibols. Fully-grown fungal cultures on potato-dextrose agar were extracted with CH2Cl2/MeOH, and these extracts were subjected to SPE using C18 cartridges. The methanolic eluates were analyzed by on-line LC/ESI-MSn coupling , a method which is referred to as ,peptaibiomics'. New seven-, ten-, and eleven-residue lipopeptaibols, with N -terminal alkanoyl, and C -terminal leucinol or isoleucinol residues were found and named lipostrigocins and lipopubescins. Furthermore, new 18-residue peptaibols named trichostromaticins and 19-residue peptaibols named trichostrigocins were discovered. One peptaibiotic carrying a free C -terminal valine (or isovaline) named trichocompactin XII was also sequenced. These results corroborate the hypothesis that peptaibiotics might contribute to the plant-protective action of their fungal producers. The data also point out that comparison of peptaibiotic sequences is of limited relevance in order to establish chemotaxonomic relationships among species of the genus Trichoderma. [source]

Use of monoclonal antibodies to quantify the dynamics of ,-galactosidase and endo-1,4-,-glucanase production by Trichoderma hamatum during saprotrophic growth and sporulation in peat

ENVIRONMENTAL MICROBIOLOGY, Issue 5 2005
Christopher R. Thornton
Summary Trichoderma species are ubiquitous soil and peat-borne saprotrophs that have received enormous scientific interest as biocontrol agents of plant diseases caused by destructive root pathogens. Mechanisms of biocontrol such as antibiosis and hyperparasitism are well documented and the biochemistry and molecular genetics of these processes defined. An aspect of biocontrol that has received little attention is the ability of Trichoderma species to compete for nutrients in their natural environments. Trichoderma species are efficient producers of polysaccharide-degrading enzymes that enable them to colonize organic matter thereby preventing the saprotrophic spread of plant pathogens. This study details the use of monoclonal antibodies (mAbs) to quantify the production of two enzymes implicated in the saprotrophic growth of Trichoderma species in peat. Using mAbs specific to the hemicellulase enzyme ,-galactosidase (AGL) and the cellulase enzyme endo-1,4-,-glucanase (EG), the relationship between the saprotrophic growth dynamics of a biocontrol strain of Trichoderma hamatum and the concomitant production of these enzymes in peat-based microcosms was studied. Enzyme activity assays and enzyme protein concentrations derived by enzyme-linked immunosorbent assay (ELISA) established the precision and sensitivity of mAb-based assays in quantifying enzyme production during active growth of the fungus. Trends in enzyme activities and protein concentrations were similar for both enzymes, during a 21-day sampling period in which active growth and sporulation of the fungus in peat was quantified using an independent mAb-based assay. There was a sharp increase in active biomass of T. hamatum 3 days after inoculation of microcosms with phialoconidia. After 3 days there was a rapid decline in active biomass which coincided with sporulation of the fungus. A similar trend was witnessed with EG activities and concentrations. This showed that EG production related directly to active growth of the fungus. The trend was not found, however, with AGL. There was a rapid increase in enzyme activities and protein concentrations on day 3, after which they remained static. The reason for the maintenance of elevated AGL probably resulted from secretion of the enzyme from conidia and chlamydospores. ELISA, immunofluoresence and immunogold electron microscopy studies of these cells showed that the enzyme is localized within the cytoplasm and is secreted extracellularly into the surrounding environment. It is postulated that release of oligosaccharides from polymeric hemicellulose by the constitutive spore-bound enzyme leads to AGL induction and could act as an environmental cue for spore germination. [source]

Trichoderma biodiversity in China: Evidence for a North to South distribution of species in East Asia

FEMS MICROBIOLOGY LETTERS, Issue 2 2005
Chu-long Zhang
Abstract Towards assessing the biodiversity and biogeography of Trichoderma, we have analyzed the occurrence of Trichoderma species in soil and litter from four areas in China: North (Hebei province), South-East (Zhejiang province), West (Himalayan, Tibet) and South-West (Yunnan province). One hundred and thirty five isolates were grouped according to tentative morphological identification. A representative 64 isolates were verified at the species level by the oligonucleotide barcode program TrichO Key v.1.0 and the custom BLAST server Tricho BLAST, using sequences of the ITS1 and 2 region of the rRNA cluster and from the longest intron of the tef1 (translation elongation factor 1-,) gene. Eleven known species (Trichoderma asperellum, T. koningii, T. atroviride, T. viride, T. velutinum, T. cerinum, T. virens, T. harzianum, T. sinensis, T. citrinoviride, T. longibrachiatum) and two putative new species (T. sp. C1, and T. sp. C2), distinguished from known species both by morphological characters and phylogenetic analysis, were identified. A significant difference in the occurrence of these species was found between the North (Hebei) and South-West (Yunnan) areas, which correlates with previously reported species distributions in Siberia and South-East Asia, respectively. As in previous studies, T. harzianum accounted for almost half of the biodiversity; although, in this study, it was exclusively found in the North, and was predominantly represented by an ITS1 and 2 haplotype, which has so far been rarely found elsewhere. This study therefore reveals a North,South gradient in species distribution in East Asia, and identifies Northern China as a potential center of origin of a unique haplotype of T. harzianum. [source]

Exploring the species diversity of Trichoderma in Norwegian drinking water systems by DNA barcoding

MOLECULAR ECOLOGY RESOURCES, Issue 6 2008
GUNHILD HAGESKAL
Abstract A total of 123 Trichoderma strains were isolated from Norwegian surface-sourced drinking water. The water samples included raw water, treated water, and water from private homes and hospital installations. Trichoderma species are difficult to differentiate morphologically, but recent molecular identification tools, including DNA barcoding, successfully distinguish between closely related species. The diversity of Trichoderma spp. was explored by DNA sequencing of internal transcribed spacer (ITS) and translation elongation factor 1 alpha (TEF-1,). Sequence identification was performed in the TrichOKEY version 2.0 barcode program and in the multilocus similarity search database TrichoBLAST, combined with traditional blast searches in the EMBL/GenBank. A total of 11 known Trichoderma/Hypocrea species were identified. In addition, one group of unidentified Trichoderma strains was found to represent a separate, strongly supported subclade within the Pachybasium,A'/Hamatum clade, based on their TEF-1, haplotypes. Trichoderma viride comprised 49% of the identified strains, and was represented by four and eight slightly different ITS and TEF-1, haplotypes, respectively. Approximately 22% of the surface-derived water samples were positive for T. viride, and the species was frequently isolated throughout the surface-sourced drinking water distribution system. The results indicate that a broad range of Trichoderma species are present in Norwegian surface-sourced drinking. Water treatment has minor effect in removing Trichoderma from raw water, and active growth in the water distribution system is likely to occur. [source]

Enhanced biocontrol activity of Trichoderma virens transformants constitutively coexpressing ,-1,3- and ,-1,6-glucanase genes

MOLECULAR PLANT PATHOLOGY, Issue 4 2007
SLAVICA DJONOVI
SUMMARY Evidence for the role of chitinases, proteases and ,-1,3- and ,-1,6-glucanases in mycoparasitism by Trichoderma species has been well documented. Moreover, constitutive over-expression of genes encoding individual cell-wall-degrading enzymes (CWDEs) has been shown to improve the potential of biological agents. In this study, we generated transformants of T. virens in which ,-1,3- and ,-1,6-glucanase genes, TvBgn2 and TvBgn3, respectively, were constitutively coexpressed in the same genetic T. virens Gv29.8 wild-type background. The double over-expression transformants (dOEs) grow and sporulate slower than the wild-type (WT). However, the reduction in growth did not seem to affect their mycoparasitic and biocontrol capabilities, as dOEs displayed much higher levels of total ,-1,3- and ,-1,6-glucanase activity than the WT. This higher enzymatic activity of dOEs positively correlated with observed in vitro inhibition of Pythium ultimum and Rhizoctonia solani mycelia, and with enhanced bioprotection of cotton seedlings against P. ultimum, R. solani and Rhizopus oryzae. Besides effective biocontrol of all pathogens at an original inoculum level, the performance of dOEs was highly enhanced (up to 312% of WT performance) when pathogen pressure was greater (i.e. concentration of inoculum was higher or pathogens applied in combination). These results demonstrate that the strategy of introducing multiple lytic enzyme-encoding genes through transformation of a given biocontrol strain can be successfully used to achieve better biocontrol. [source]

Tandem electrospray mass spectrometric studies of proton and sodium ion adducts of neutral peptides with modified N- and C-termini: synthetic model peptides and microheterogeneous peptaibol antibiotics

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 4 2006
Varatharajan Sabareesh
The fragmentations of [M+H]+ and [M+Na]+ adducts of neutral peptides with blocked N- and C-termini have been investigated using electrospray ion trap mass spectrometry. The N-termini of these synthetically designed peptides are blocked with a tertiarybutyloxycarbonyl (Boc) group, and the C-termini are esterified. These peptides do not possess side chains that are capable of complexation and hence the backbone amide units are the sole sites of protonation and metallation. The cleavage patterns of the protonated peptides are strikingly different from those of sodium ion adducts. While the loss of the N-terminal blocking group occurs quite readily in the case of MS/MS of [M+Na]+, the cleavage of the C-terminal methoxy group seems to be a facile process in the case of MS/MS of [M+H]+. Fragmentation of the protonated adducts yields only bn ions, while yn and an ions are predominantly formed from the fragmentation of sodium ion adducts. The an ions arising from the fragmentation of [M+Na]+ lack the N-terminal Boc group (and are here termed an* ions). MS/MS of [M+Na]+ species also yields bn ions of substantially lower intensities that lack the N-terminal Boc group (bn*). A similar distinction between the fragmentation patterns of proton and sodium ion adducts is observed in the case of peptides possessing an N-terminal acetyl group. An example of the fragmentation of the H+ and Na+ adducts of a naturally occurring peptaibol from a Trichoderma species confirms that fragmentation of these two ionized species yields complementary information, useful in sequencing natural peptides. Inspection of the isotopic pattern of bn ions derived from [M+H]+ adducts of peptaibols provided insights into the sequences of microheterogeneous samples. This study reveals that the combined use of protonated and sodium ion adducts should prove useful in de novo sequencing of peptides, particularly of naturally occurring neutral peptides with modified N- and C-termini, for example, peptaibols. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Colonisation of grapevine wood by Trichoderma harzianum and Eutypa lata

AUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 1 2008
S. JOHN
Abstract Background and Aims:,Trichoderma species have potential in biocontrol of eutypa dieback; however, little is known about their ability to colonise grapevine wood. The colonisation of vines by Trichoderma harzianum and its effects on colonisation by Eutypa lata were studied. Methods and Results:,T. harzianum colonised canes over a total distance (above and below the inoculation point) of 10 cm or more in 12 weeks after inoculation. Application of T. harzianum to canes prior to E. lata, either at the same inoculation point or at a different point, reduced recovery of the pathogen. In the field, T. harzianum grew 3 cm from the inoculation point in 4 months in all seven of the mature vines treated. The fungus persisted for 20 months in four of the seven vines at 6 cm from the inoculation point and reached the crown of one vine. Prior inoculation of mature vines with Trichodowels, containing T. harzianum, reduced recovery of E. lata 14 months after inoculation. Conclusions:,T. harzianum colonised wood of Chardonnay, Shiraz and Nyora and reduced colonisation by E. lata. T. harzianum persisted in wood of mature vines of Nyora for up to 20 months. Significance of the Study:, The results support the potential of T. harzianum in the biocontrol of eutypa dieback. [source]

Recent Advances and Future Prospects in Peptaibiotics, Hydrophobin, and Mycotoxin Research, and Their Importance for Chemotaxonomy of Trichoderma and Hypocrea

CHEMISTRY & BIODIVERSITY, Issue 5 2008
Thomas Degenkolb
Abstract Fungi of the genus Trichoderma with teleomorphs in Hypocrea are abundant producers of a group of amphiphilic, non-ribosomal peptide antibiotics, which are rich in the non-proteinogenic amino acid Aib (, -aminoisobutyric acid). They are referred to as peptaibiotics, or peptaibols, if a 1,2-amino alcohol is present at the C-terminus. Trichoderma/Hypocrea, like other ascomycetous fungi, also produce hydrophobins, a class of small, cysteine-rich proteins. Advanced soft ionization mass spectrometric techniques such as LC-CID-MS, LC-ESI-MSn, and IC-MALDI-TOF-MS enabled the high-throughput analysis, simultaneous detection and sequence determination of peptaibiotics and hydrophobins from minute quantities of fungal materials. Some Trichoderma species have been recognized to produce peptaibiotics as well as simple mycotoxins of the trichothecene group. The combination of sequence data of both groups of peptides with the pattern of low-molecular-weight secondary metabolites, including trichothecene-type mycotoxins, independently confirmed the results of morphological, molecular, and phylogenetic analyses. This approach established a new lineage in Trichoderma/Hypocrea, the Brevicompactum clade, comprising four new and one redescribed species. Notably, commercial preparations of single or mixed cultures of Trichoderma species, in particular T. harzianum, and T. koningii, are registered as biocontrol agents for soil and plant pathogens. In this context, it is emphasized that the four mycotoxin-producing species of the recently established Brevicompactum clade (T. brevicompactum, T. arundinaceum, T. turrialbense, and T. protrudens) are not closely related to any of the Trichoderma species currently used as biocontrol agents. Furthermore, possible health concerns about release of peptaibiotics in the biosphere are discussed with respect to their bioactivities and their use as drugs in human and veterinary medicine. Finally, future prospects regarding novel bioactivities and further research needs, including interdisciplinary taxonomic approaches, are outlined. [source]