title: Temporal dynamics of microbial communities in the rhizosphere of two genetically modified (GM) maize hybrids in tropical agrosystems.
abstract: The use of genetically modified (GM) plants still raises concerns about their environmental impact. The present study aimed to evaluate the possible effects of GM maize, in comparison to the parental line, on the structure and abundance of microbial communities in the rhizosphere. Moreover, the effect of soil type was addressed. For this purpose, the bacterial and fungal communities associated with the rhizosphere of GM plants were compared by culture-independent methodologies to the near-isogenic parental line. Two different soils and three stages of plant development in two different periods of the year were included. As evidenced by principal components analysis (PCA) of the PCR-DGGE profiles of evaluated community, clear differences occurred in these rhizosphere communities between soils and the periods of the year that maize was cultivated. However, there were no discernible effects of the GM lines as compared to the parental line. For all microbial communities evaluated, soil type and the period of the year that the maize was cultivated were the main factors that influenced their structures. No differences were observed in the abundances of total bacteria between the rhizospheres of GM and parental plant lines.
authors.affiliation: Laboratório de Genética Microbiana, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde, Bloco I Ilha do Fundão, Rio de Janeiro, RJ, CEP 21941-590, Brazil.
authors.forename: Simone Raposo
authors.initials: SR
authors.lastname: Cotta
authors.forename: Armando Cavalcante Franco
authors.initials: AC
authors.lastname: Dias
authors.forename: Ivanildo Evódio
authors.initials: IE
authors.lastname: Marriel
authors.forename: Eliane Aparecida
authors.initials: EA
authors.lastname: Gomes
authors.forename: Jan Dirk
authors.initials: JD
authors.lastname: van Elsas
authors.forename: Lucy
authors.initials: L
authors.lastname: Seldin
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics; D058448:Biota; D016000:Cluster Analysis; D058645:Denaturing Gradient Gel Electrophoresis; D005658:Fungi / Q000145:classification* / Q000235:genetics; D054892:Metagenome; D018517:Plant Roots / Q000382:microbiology*; D030821:Plants, Genetically Modified / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D058441:Rhizosphere; D013997:Time Factors; D003313:Zea mays / Q000382:microbiology*