title: Plant Growth Promoting Bacteria Associated withLangsdorffia hypogaea-Rhizosphere-Host Biological Interface: A Neglected Model of Bacterial Prospection.
abstract: Soil is a habitat where plant roots and microorganisms interact. In the region of the Brazilian Iron Quadrangle (IQ), studies involving the interaction between microbiota and plants have been neglected. Even more neglected are the studies involving the holoparasite plantLangsdorffia hypogaeaMart. (Balanophoraceae). The geomorphological peculiarities of IQ soil, rich in iron ore, as well as the model of interaction betweenL. hypogaea, its hosts and the soil provide a unique niche that acts as selective pressure to the evolution of plant growth-promoting bacteria (PGPB). The aim of this study was to prospect the bacterial microbiota of holoparasitic plantL. hypogaea, its plant host and corresponding rhizosphere of IQ soil, and to analyze the potential of these isolates as PGPB. We obtained samples of 11 individuals ofL. hypogaeacontaining fragments of host and rhizosphere remnants, resulting in 81 isolates associated with Firmicutes and Proteobacteria phyla. The ability to produce siderophores, hydrocyanic acid (HCN), indole-3-acetic acid (IAA), nitrogen (N2) fixation, hydrolytic enzymes secretion and inhibition of enteropathogens, and phytopathogens were evaluated. Of the total isolates, 62, 86, and 93% produced, respectively, siderophores, IAA, and were able to fix N2. In addition, 27 and 20% of isolates inhibited the growth of enteropathogens and phytopathogens, respectively, and 58% were able to produce at least one hydrolytic activity investigated. The high number of isolates that produce siderophores and indole-3-acetic acid suggests that this microbiota may be important for adaptation of plants to IQ. The results demonstrate for the first time the biological importance of Brazilian IQ species as reservoirs of specific microbiotas that might be used as PGPB on agricultural land or antropized soils that needs to be reforested.
authors.affiliation: Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro PretoOuro Preto, Brazil; Laboratório de Genômica e Interação Microrganismos-Ambiente, Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Campus Morro do CruzeiroOuro Preto, Brazil.
authors.forename: Érica B
authors.initials: ÉB
authors.lastname: Felestrino
authors.affiliation: Laboratório de Ecologia e Biotecnologia de Leveduras, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais Belo Horizonte, Brazil.
authors.forename: Iara F
authors.initials: IF
authors.lastname: Santiago
authors.affiliation: Programa de Pós-Graduação em Biomas Tropicais, Departamento de Biodiversidade, Evolução e Meio Ambiente, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto Ouro Preto, Brazil.
authors.forename: Luana da Silva
authors.initials: LD
authors.lastname: Freitas
authors.affiliation: Laboratório de Ecologia e Biotecnologia de Leveduras, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais Belo Horizonte, Brazil.
authors.forename: Luiz H
authors.initials: LH
authors.lastname: Rosa
authors.affiliation: Programa de Pós-Graduação em Biomas Tropicais, Departamento de Biodiversidade, Evolução e Meio Ambiente, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto Ouro Preto, Brazil.
authors.forename: Sérvio P
authors.initials: SP
authors.lastname: Ribeiro
authors.affiliation: Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro PretoOuro Preto, Brazil; Laboratório de Genômica e Interação Microrganismos-Ambiente, Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Campus Morro do CruzeiroOuro Preto, Brazil.
authors.forename: Leandro M
authors.initials: LM
authors.lastname: Moreira
keywords: Brazilian Iron Quadrangle; IAA and siderophores; Langsdorffia hypongaea; bioprospecting; biotechnological potential; plant growth-promoting bacteria