The diazotrophic, bacterial endophyte Herbaspirillum frisingense GSF30T has been identified in biomass grasses grown in temperate climate, including the highly nitrogen-efficient grass Miscanthus. Its genome was annotated and compared with related Herbaspirillum species from diverse habitats, including H. seropedicae, and further well-characterized endophytes. The analysis revealed that Herbaspirillum frisingense lacks a type III secretion system that is present in some related Herbaspirillum grass endophytes. Together with the lack of components of the type II secretion system, the genomic inventory indicates distinct interaction scenarios of endophytic Herbaspirillum strains with plants. Differences in respiration, carbon, nitrogen and cell wall metabolism among Herbaspirillum isolates partially correlate with their different habitats. Herbaspirillum frisingense is closely related to strains isolated from the rhizosphere of phragmites and from well water, but these lack nitrogen fixation and metabolism genes. Within grass endophytes, the high diversity in their genomic inventory suggests that even individual plant species provide distinct, highly diverse metabolic niches for successful endophyte-plant associations.
Keywords: microbe, diazotroph, nitrogen fixation, plant associated bacteria, plant growth promoting bacteria
Citation: Straub D, Rothballer M, Hartmann A and Ludewig U (2013) The genome of the endophytic bacterium H. frisingense GSF30T identifies diverse strategies in the Herbaspirillum genus to interact with plants. Front. Microbiol. 4:168. doi: 10.3389/fmicb.2013.00168
Received: 13 March 2013; Accepted: 03 June 2013;
Published online: 27 June 2013.
Edited by:Eric Altermann, AgResearch Ltd, New Zealand
Reviewed by:Loren J. Hauser, Oak Ridge National Laboratory, USA
Copyright © 2013 Straub, Rothballer, Hartmann and Ludewig. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Uwe Ludewig, Institut für Kulturpflanzenwissenschaften, Ernährungsphysiologie der Kulturpflanzen (340h), Universität Hohenheim, Fruwirthstr. 20, D-70593 Stuttgart, Germany e-mail: firstname.lastname@example.org