Morfologia da ectomicorriza Scleroderma laeve - Eucalyptus grandis e análise da expressão do gene que codifica a subunidade seis de ATP sintase

• Autor(a) principal: Betancourth, Blanca Mercedes Leguízamo
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4756
• topic: Scleroderma laeve; ATP sintase; Associação ectomicorrizica; Expressão gênica; Scleroderma laeve; ATP synthase; Ectomycorrhiza association; Gene expression; CNPQ::CIENCIAS BIOLOGICAS::GENETICA

Scleroderma laeve is a basidiomycete fungus capable of forming ectomycorrhizas with Eucalyptus grandis. Significant increases in lateral root production were observed in E. grandis plants inoculated with S. leave during the presymbiotic phase. This was also observed during the colonization, differentiation, and functioning stages of the symbiosis. On the third day of contact of the fungus with the host, the partial elongation of epidermal cells and mantle formation were observed, and, on the fifteenth day, the beginning of Hartig net formation was evident. On the 30th day, lateral root numbers in the plants in contact with the fungus was higher than in the control plants. The elongation of the epidermal cell and the thickening of the mantle could also be observed. The emerging lateral roots colonized by the fungus did not present root hairs, were completely enveloped by the fungal mantle, and had a fully developed Hartig net between the epidermal cells. The periodical sampling of lateral roots and ectomycorrhizas at different developmental stages in the in vitro system allowed following the morphological development of ectomycorrhizas and the corresponding changes in the expression of the gene coding for ATP synthase subunit VI in S. leave. The partial sequence of the ATP synthase subunit VI gene obtained possesses 503 bp and no intron. This sequences showed an identity to the sequences of the genes that code for e ATP synthase subunit VI in Scleroderma hypogaeum, Pisolithus arhizus, and Gyroporus cyanescens, among others, confirming the close relationship among these organisms. The expression analysis of the ATP synthase subunit VI gene in S. laeve by RT-PCR, at the different developmental stages of the symbiotic association, showed that the gene is expressed in all the phases of mycorrhization.