The communities of tomato (Solanum lycopersicum L.) leaf-endophytic bacteria, analyzed by 16S-ribosomal DNA pyrosequencing

ROMERO FM; MARINA M; PIECKENSTAIN FL

FEMS MICROBIOLOGY LETTERS

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2014 vol. 351 p. 187 - 194

0378-1097

Endophytic bacterial communities of tomato leaves were analyzed by 16S rDNA 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 (>1,700 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.