Análise do transcriptoma de Trichoderma harzianum em resposta a exposição a cádmio

• Ano de defesa: 2019
• Autor(a) principal: Oshiquiri, Letícia Harumi
• Orientador(a): Georg, Raphaela de Castro
• Banca de defesa: Georg, Raphaela de Castro, Gomes, Suely Lopes, Bailão, Alexandre Melo, Ulhoa, Cirano José
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• dARK ID: ark:/38995/001300000947p
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Ciências Biológicas (ICB)
• Departamento: Instituto de Ciências Biológicas - ICB (RG)
• País: Brasil
• Palavras-chave em Português: Trichoderma harzianum; RNA-Seq; Cádmio; Expressão gênica; Metais
• Palavras-chave em Inglês: RNA-Seq; Cadmium; Metals; Gene expression
• Área do conhecimento CNPq: CIENCIAS BIOLOGICAS::BIOQUIMICA
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/9389

Excessive amounts of metals in soil can cause toxic effects to microorganisms, plants and animals. In contaminated regions, Trichoderma, a filamentous fungus capable of surviving in various environments, have already been isolated. The mechanisms involved in its metal tolerance are not yet fully understood, therefore, in order to evaluate Trichoderma harzianum response to cadmium, this report described the growth characteristics of the fungus and identified the gene expression profile at different concentrations of the metal, then using this data, searched for possible consensus sequences involved in its regulation. Of 13,932 genes predicted by the reference genome, 3,767 and 2,986 were differentially expressed when exposed to 1 mg.ml-1 and 2 mg.ml-1 of CdCl2, respectively. Of these genes, 2,562 were common to both treatments. Biological processes related to cellular homeostasis, transcription initiation, metabolic processes of sulfur compounds, RNA processing, protein modification and transport mediated by vesicles were up-regulated. It was observed that glutathione synthesis and its precursors’ pathways were up-regulated. Interestingly, various genes coding spliceosome components were identified. Carbohydrate, fatty acids and ionic transport metabolism were down-regulated, including important genes for the mycoparasitic potential of the fungus. Among the top down-regulated genes were genes of unknown function, therefore this analysis allowed an initial characterization of these genes. The main transcription factors related to the regulation of these genes were predicted as Cup2 (copper resistance), Cad1 (cadmium resistance) and Azf1-like (growth and proliferation). Together, the data obtained in this work suggests that the process of adaptation of T. harzianum to the presence of the metal cadmium involves the induction of several mechanisms of tolerance such as conjugation with glutathione, transport, compartmentalization in vacuoles, precipitation by sulfide, combat of ROS, DNA repair systems and quality control system for protein folding.