title: Endophytic bacterial diversity in the phyllosphere of Amazon Paullinia cupana associated with asymptomatic and symptomatic anthracnose.
abstract: Endophytes colonize an ecological niche similar to that of phytopathogens, which make them candidate for disease suppression. Anthracnose is a disease caused by Colletotrichum spp., a phytopathogen that can infect guarana (Paullinia cupana), an important commercial crop in the Brazilian Amazon. We investigated the diversity of endophytic bacteria inhabiting the phyllosphere of asymptomatic and symptomatic anthracnose guarana plants. The PCR-denaturation gradient gel electrophoresis (PCR-DGGE) fingerprints revealed differences in the structure of the evaluated communities. Detailed analysis of endophytic bacteria composition using culture-dependent and 16S rRNA clone libraries revealed the presence of Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Acidobacteria phyla. Firmicutes comprised the majority of isolates in asymptomatic plants (2.40E(-4)). However, cloning and sequencing of 16S rRNA revealed differences at the genus level for Neisseria (1.4E(-4)), Haemophilus (2.1E(-3)) and Arsenophonus (3.6E(-5)) in asymptomatic plants, Aquicella (3.5E(-3)) in symptomatic anthracnose plants, and Pseudomonas (1.1E(-3)), which was mainly identified in asymptomatic plants. In cross-comparisons of the endophytic bacterial communities as a whole, symptomatic anthracnose plants contained higher diversity, as reflected in the Shannon-Weaver and Simpson indices estimation (P < 0.05). Similarly, comparisons using LIBSHUFF and heatmap analysis for the relative abundance of operational taxonomic units (OTUs) showed differences between endophytic bacterial communities. These data are in agreement with the NMSD and ANOSIM analysis of DGGE profiles. Our results suggest that anthracnose can restructure endophytic bacterial communities by selecting certain strains in the phyllosphere of P. cupana. The understanding of these interactions is important for the development of strategies of biocontrol for Colletotrichum.
authors.affiliation: Department of Genetics, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Av. Pádua Dias 11, PO BOX 83, Piracicaba, SP 13400-970 Brazil.
authors.forename: Andréa Cristina
authors.initials: AC
authors.lastname: Bogas
authors.affiliation: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374-Ed. Biomédicas II, Cidade Universitária, São Paulo, SP 05508-900 Brazil.
authors.forename: Almir José
authors.initials: AJ
authors.lastname: Ferreira
authors.affiliation: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374-Ed. Biomédicas II, Cidade Universitária, São Paulo, SP 05508-900 Brazil.
authors.forename: Welington Luiz
authors.initials: WL
authors.lastname: Araújo
authors.affiliation: Molecular Diagnostic Laboratory, Biotechnology Division, Federal University of Amazon, Av. Gal. Rodrigo Octávio Jordão, 3000, Manaus, AM 69.077-000 Brazil.
authors.forename: Spartaco
authors.initials: S
authors.lastname: Astolfi-Filho
authors.affiliation: Department of Plant Pathology and Nematology, ''Luiz de Queiroz'' College of Agriculture, University of São Paulo, Av. Pádua Dias 11, Piracicaba, SP 13418-900 Brazil.
authors.forename: Elliot Watanabe
authors.initials: EW
authors.lastname: Kitajima
authors.affiliation: Center of Biological Sciences and Health, Federal University of São Carlos, Via Washington Luís km 235, PO BOX 676, São Carlos, SP 13565-905 Brazil.
authors.forename: Paulo Teixeira
authors.initials: PT
authors.lastname: Lacava
authors.affiliation: Department of Genetics, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Av. Pádua Dias 11, PO BOX 83, Piracicaba, SP 13400-970 Brazil.
authors.forename: João Lúcio
authors.initials: JL
authors.lastname: Azevedo
keywords: Clone library; Colletotrichum; Culture dependent; Endophytes; Microbial diversity; PCR-DGGE