title: The communities of tomato (Solanum lycopersicum L.) leaf endophytic bacteria, analyzed by 16S-ribosomal RNA gene pyrosequencing.
abstract: Endophytic bacterial communities of tomato leaves were analyzed by 16S-rRNA gene pyrosequencing and compared to rhizosphere communities. Leaf endophytes mainly comprised five phyla, among which Proteobacteria was the most represented (90%), followed by Actinobacteria (1,5%), Planctomycetes (1,4%), Verrucomicrobia (1,1%), and Acidobacteria (0,5%). Gammaproteobacteria was the most abundant class of Proteobacteria (84%), while Alphaproteobacteria and Betaproteobacteria represented 12% and 4% of this phylum, respectively. Rarefaction curves for endophytic bacteria saturated at 80 OTUs, indicating a lower diversity as compared to rhizosphere samples (> 1700 OTUs). Hierarchical clustering also revealed that leaf endophytic communities strongly differed from rhizospheric ones. Some OTUs assigned to Bacillus, Stenotrophomonas, and Acinetobacter, as well as some unclassified Enterobacteriaceae were specific for the endophytic community, probably representing bacteria specialized in colonizing this niche. On the other hand, some OTUs detected in the leaf endophytic community were also present in the rhizosphere, probably representing soil bacteria that endophytically colonize leaves. As a whole, this study describes the composition of the endophytic bacterial communities of tomato leaves, identifying a variety of genera that could exert multiple effects on growth and health of tomato plants.
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico Chascomús, Universidad Nacional de General San Martín-Consejo Nacional de Investigaciones Científicas y Técnicas (IIB-INTECH/UNSAM-CONICET), Chascomús, Argentina.
authors.forename: Fernando M
authors.initials: FM
authors.lastname: Romero
authors.forename: María
authors.initials: M
authors.lastname: Marina
authors.forename: Fernando L
authors.initials: FL
authors.lastname: Pieckenstain
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D058448:Biota; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D060026:Endophytes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D018551:Solanum lycopersicum / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D018515:Plant Leaves / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S
keywords: bacterial diversity; culture-independent bacterial analysis; plant endophytic bacteria