Identificação e caracterização dos genes abcCl1 e cypCl1 que codificam um transportador ABC e um citocromo P450 no fitopatógeno Colletotrichum lindemuthianum

• Ano de defesa: 2009
• Autor(a) principal: Oliveira, Maycon Campos
• Orientador(a): Queiroz, Marisa Vieira de
• Banca de defesa: Mantovani, Hilário Cuquetto , Pereira, Olinto Liparini
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Microbiologia Agrícola
• Departamento: Associações micorrízicas; Bactérias láticas e probióticos; Biologia molecular de fungos de interesse
• País: BR
• Palavras-chave em Português: Colletotrichum lindemuthianum; Phaseolus vulgaris; Transportador ABC; Citocromo P450
• Palavras-chave em Inglês: Colletotrichum lindemuthianum; Phaseolus vulgaris; ABC transporter; Cytochrome P450
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA MOLECULAR E DE MICROORGANISMOS
• Link de acesso: http://locus.ufv.br/handle/123456789/5303

The plants produce antifungous proteins and specialized antibiotics (phytoanticipins and phytoalexins) in order to defend from phytopathogenic fungus. Only the pathogens able to avoid those defensive plant responses at the initial stages of the infection are able to cause disease. The fungus Colletotrichum lindemuthianum (Sacc. & Magnus) Briosi & Cavara is the etiological agent of the anthracnose in the common bean plant (Phaseolus vulgaris L.), that is an important disease contributing to reduce the productivity of the bean plant crop in Brazil. The genes abcCl1 and cypCl1 were isolated from this phytopathogen and their deduced aminoacid sequences have high similarity with ABC transporters and cytochromes P450, respectively. Those genes are found in unique copy and clustered in genome of the fungus, as revealed by either the sequencing of one DNA 8,4 kb fragment from the genomic library of C. lindemuthianum and the hybridization profile. Those genes also show an increased expression in response to different toxic compounds, mainly when the fungus is grown at the presence of eugenol, hygromycin and pisatin phytoalexin. Therefore, besides their genes to be physically linked, the proteins ABCCl1 and CYPCl1 can also be involved in the same functional process: the fungus resistance to the toxic compounds produced by plants or antagonistic microorganisms. In the functional analysis of the gene abcCl1, the mutants abcCl1− showed reduction in their virulence to the leaf of the common bean plant, compared with the wild line of C. lindemuthianum. Those results indicate the gene abcCl1 to codify an ABC transporter that is necessary to pathogenicity of C. lindemuthianum, probably because providing the fungus with the ability to overcome the defense mechanism of the plant. The cytochrome P450, that is codified by the gene cypCl1, can represent a complementary detoxification mechanism used by this fungus during the establishment of the disease.