Navegando por Assunto "micoparasitismo"
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Item Análise do secretoma do fungo Trichoderma harzianum crescido em presença de glicose ou parede celular de Fusarium solani(Universidade Federal de Goiás, 2010-03-31) RAMADA, Marcelo Henrique Soller; MONTEIRO, Valdirene Neves; http://lattes.cnpq.br/8264822485508916; ULHOA, Cirano Jose; http://lattes.cnpq.br/8368469162867277Trichoderma harzianum is a saprophytic fungus, known for its potential as a biological control agent of different phytopathogens that causes losses in crops. Its action is based on different mechanisms like volatile and non-volatile antibiotics production, competition for nutrient and space, production of hydrolytic enzymes and mycoparasitism. Fusarium solani is the agent of bean dry root rot, and is responsible for significant losses. This work sought to analyze and identify secreted proteins from T. harzianum grown in the presence of F. solani cell wall, in an attempt to obtain new insights on biocontrol.In the dual culture test, T. harzianum proved to be a potent antagonist of F. solani. Some differences in the secreted proteins profile and final medium pH were observed when T. harzianum was grown in TLE medium containing glucose and in TLE and Minimum medium containing the cell wall of the phytopathogen. 33 proteins from 18 different genes were identified. The protein Sm1 was identified and secreted in all growth conditions. Many hydrolytic enzymes related to mycoparasitism, like endochitinases, β-1,3, β-1,6-glucanases, proteases and α-1,3-glicanases, were identified and among the proteases, a hypothetical metalocarboxipeptidase and a serine subtilisin-like never described for T. harzianum. Some enzymes with unkown roles in the mycoparasitism, such as β-1,3-glucanosyltransferase, secreted only in MM growth medium supernatant, were also identified.Item Construção e análise de uma biblioteca de cDNA de Trichoderma harzianum crescido na presença de parede celular de Fusarium solani(Universidade Federal de Goiás, 2010-02-26) STEINDORFF, Andrei Stecca; SILVA, Roberto do Nascimento; http://lattes.cnpq.br/5771309284349109; ULHOA, Cirano Jose; http://lattes.cnpq.br/8368469162867277Species of Trichoderma are commercially applied as biological control agents against plant fungal pathogens. Their action is based on a set of events, such as the production of antifungal metabolites, competition for space and nutrients and mycoparasitism. However the biocontrol mechanism of the interaction between Trichoderma harzianum and Fusarium solani is not yet understanded at the transcriptome level. This study aimed to initiate the preliminary development of an expressed sequence tag (EST) database for Trichoderma harzianum and thereby gain potentially useful information on Trichoderma gene sequences in order to elucidate the integrated biocontrol mechanism. Partial sequencing of anonymous cDNA clones is a widely used technique for gene identification. A directional cDNA library has been constructed from mycelium of Trichoderma harzianum grown on cell wall isolated from Fusarium solani. 3984 clones have been randomly selected, subjected to single-pass sequencing from the 5 end of the vector, and identified by sequence similarity searches against gene sequences in GenBank fungal database. Of the 3984 mycelium clones, 40.8% exhibit similarity to known genes. Analysis of the identified clones indicated sequence similarity to a broad diversity of genes encoding proteins such as enzymes, structural proteins, and regulatory factors. A significant proportion of genes identified were involved in processes related to mycoparasitism (3,81%), as would be expected in biocontrol fungus. These results present the successful application of EST analysis in the interaction of Trichoderma harzianum and Fusarium solani to provide a preliminary indication of gene expression.