Interaction between arbuscular mycorrhizal fungi and soil microbiota

Author(s)

Dorotéia Alves Ferreira

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC)
• Defense date: 2016-07-25

Examining board members

Fernando Dini Andreote; Elke Jurandy Bran Nogueira Cardoso; Marco Aurelio Carbone Carneiro; Rodrigo Mendes

• Advisor: Fernando Dini Andreote

Abstract

Knowledge about the associations between microbial components of soil microbiota is of great interest in the scientific community, primarily related to microorganisms that are associated beneficially with plants. In this context, there is the arbuscular mycorrhiza, which is made of the association between mycorrhizal fungi (AMF) and a range of plant species. In this close interaction between these organisms, it is necessary to describe the importance of other components of the soil system, such as the microbiota formed by fungi and bacteria from the soil, to establish this interaction. The objectives of the studied that compose this thesis focused on the evaluation of AMF (D. heterogama, R. clarus and Gi. rosea) fitness, when inoculated in modified systems on the composition of the microbial communities in the soil, with alterations promoted by the \'dilution to extinction\' methodology. In the first study, differential responses were found in root colonization capacity (% CM) of sugarcane by AMF inoculated in different systems, and the differential effect of AMFs, changing the communities of fungi and bacteria of soil. In a more detailed study, designed only to R. clarus in corn plants, it was found that higher microbial diversity of soil resulted in higher colonization of the host, especially in the initial period of plant development. In this experiment it was described the direct correlation of AMF colonization capacity with richness and phylogenetic diversity of soil microbiota. The description of the metabolic profiles of soil containing various microbial communities revealed the differential ability of these soils utilize different carbon sources, in addition to demonstrating an increase in metabolism (as evidenced by the total consumption of carbon sources) due to inoculation of the AMF. Together, the data from the two studies indicate that colonization of plants by AMF depends on the action of other microorganisms soil system, which act as a third factor in this symbiosis, and that the soil microbes respond to inoculation of an exogenous organism, primarily increasing its metabolism. One should therefore consider that the biological degradation of the soil, with loss of biodiversity, may have crucial role in the functioning of specific and beneficial interactions to plants. (AU)

• FAPESP's process: 13/04388-3 - INTERACTIONS BETWEEN THE ARBUSCULAR MYCORRHIZAL FUNGI INTERACTION AND MICROBIAL COMMUNITY IN SOIL WITH SUGARCANE
• Grantee: Dorotéia Alves Ferreira
• Support Opportunities: Scholarships in Brazil - Doctorate