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Trichoderma harzianum
About: Trichoderma harzianum is a research topic. Over the lifetime, 4731 publications have been published within this topic receiving 96796 citations.
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TL;DR: In vitro antifungal activity of the ech42 disruptant culture filtrates against Botrytis cinerea and Rhizoctonia solani was reduced about 40%, compared with wild type; antif fungus activity was fully restored by adding an equivalent amount of CHIT42 as secreted by P1.
Abstract: The biocontrol strain P1 of Trichoderma harzianum was genetically modified by targeted disruption of the single-copy ech42 gene encoding for the secreted 42-kDa endochitinase (CHIT42). Stable mutants in which ech42 was interrupted, and unable to produce CHIT42, were obtained and characterized. These mutants lacked the ech42 transcript, the protein, and endochitinase activity in culture filtrates, and they were unable to clear a medium containing colloidal chitin. Other chitinolytic and glucanolytic enzymes expressed during mycoparasitism were not affected by the disruption of ech42. The disrupted mutant D11 grew and sporulated similarly to the wild type. In vitro antifungal activity of the ech42 disruptant culture filtrates against Botrytis cinerea and Rhizoctonia solani was reduced about 40%, compared with wild type; antifungal activity was fully restored by adding an equivalent amount of CHIT42 as secreted by P1. The mutant exhibited the same biocontrol effect against Pythium ultimum as strain P1, but t...
134 citations
TL;DR: A detailed examination of the metabolites produced in liquid cultures by a strain of Trichoderma harzianum, isolated from wheat roots, has resulted in the identification of five metabolites that show antibiotic activity towards the take-all fungus, Gaeumannomyces graminis var.
Abstract: A detailed examination of the metabolites produced in liquid cultures by a strain of Trichoderma harzianum, isolated from wheat roots, has resulted in the identification of a further five metabolites. Two of these, cyclonerodiol [5] and the octaketide keto diol 6, have previously been isolated from a strain of Trichoderma koningii. The structures of the three new octaketide-derived compounds 7, 8, and 10 have been deduced from spectroscopic and chemical studies. All newly isolated compounds show antibiotic activity towards the take-all fungus, Gaeumannomyces graminis var. tritici.
133 citations
TL;DR: Bee delivery of T. harzianum delivered by bumble bees or honey bees provided better Botrytis control than that applied as a spray, indicating that the use of some commercial fungicides at bloom may impact pollination and yield.
133 citations
TL;DR: A molecule that is resistant to heat and protease treatment, obtained from Rhizoctonia solani cell walls induces expression of both genes and is involved in the regulation of the expression of hydrolytic enzymes during mycoparasitism by T. harzianum.
Abstract: The mycoparasite Trichoderma harzianum has been extensively used in the biocontrol of a wide range of phytopathogenic fungi. Hydrolytic enzymes secreted by the parasite have been directly implicated in the lysis of the host. Dual cultures of Trichoderma and a host, with and without contact, were used as means to study the mycoparasitic response in Trichoderma. Northern analysis showed high-level expression of genes encoding a proteinase (prb1) and an endochitinase (ech42) in dual cultures even if contact with the host was prevented by using cellophane membranes. Neither gene was induced during the interaction of Trichoderma with lectin-coated nylon fibres, which are known to induce hyphal coiling and appressorium formation. Thus, the signal involved in triggering the production of these hydrolytic enzymes by T. harzianum during the parasitic response is independent of the recognition mediated by this lectin-carbohydrate interaction. The results showed that induction of prb1 and ech42 is contact-independent, and a diffusible molecule produced by the host is the signal that triggers expression of both genes in vivo. Furthermore, a molecule that is resistant to heat and protease treatment, obtained from Rhizoctonia solani cell walls induces expression of both genes. Thus, this molecule is involved in the regulation of the expression of hydrolytic enzymes during mycoparasitism by T. harzianum.
133 citations