Genome Survey and Characterization of Endophytic Bacteria Exhibiting a Beneficial Effect on Growth and Development of Poplar Trees

Brookhaven National Laboratory, Biology Department, Upton, NY 11973-5000, USA.
Applied and Environmental Microbiology (Impact Factor: 3.67). 02/2009; 75(3):748-57. DOI: 10.1128/AEM.02239-08
Source: PubMed

ABSTRACT The association of endophytic bacteria with their plant hosts has a beneficial effect for many different plant species. Our goal is to identify endophytic bacteria that improve the biomass production and the carbon sequestration potential of poplar trees (Populus spp.) when grown in marginal soil and to gain an insight in the mechanisms underlying plant growth promotion. Members of the Gammaproteobacteria dominated a collection of 78 bacterial endophytes isolated from poplar and willow trees. As representatives for the dominant genera of endophytic gammaproteobacteria, we selected Enterobacter sp. strain 638, Stenotrophomonas maltophilia R551-3, Pseudomonas putida W619, and Serratia proteamaculans 568 for genome sequencing and analysis of their plant growth-promoting effects, including root development. Derivatives of these endophytes, labeled with gfp, were also used to study the colonization of their poplar hosts. In greenhouse studies, poplar cuttings (Populus deltoides x Populus nigra DN-34) inoculated with Enterobacter sp. strain 638 repeatedly showed the highest increase in biomass production compared to cuttings of noninoculated control plants. Sequence data combined with the analysis of their metabolic properties resulted in the identification of many putative mechanisms, including carbon source utilization, that help these endophytes to thrive within a plant environment and to potentially affect the growth and development of their plant hosts. Understanding the interactions between endophytic bacteria and their host plants should ultimately result in the design of strategies for improved poplar biomass production on marginal soils as a feedstock for biofuels.

Download full-text


Available from: Sébastien Monchy, Sep 27, 2015
42 Reads
    • "obial communities of a salt - excreting desert tree . Additionally , various members of Gammaproteobacteria , such as Pantoea sp . , Enterobacter sp . Pseudomonas sp . Xanthomonas campestris , and Erwinia persicina in the phyllosphere ( Lindow and Brandl 2003 ; Rasche et al . 2006 ) or plant endosphere ( Kim et al . 2012 ; Madhaiyan et al . 2013 ; Taghavi et al . 2009 ; Witzel et al . 2012 ; Zhu et al . 2012 ) have been reported to be able to both promote plant growth and suppress the colonization and infection of tissues by plant pathogens . A metagenomic analysis of the rice plant en - dophytic community has shown that the endophytes , which were dominated by Gammaproteobacteria , may be involved i"
    [Show abstract] [Hide abstract]
    ABSTRACT: Plant endophytic bacteria play an important role in plant growth and health. In the context of climate change, the response of plant endophytic bacterial communities to elevated CO2 at different rice growing stages is poorly understood. Using 454 pyrosequencing, we investigated the response of leaf endophytic bacterial communities to elevated CO2 (eCO2) at the tillering, filling, and maturity stages of the rice plant under different nitrogen fertilization conditions [low nitrogen fertilization (LN) and high nitrogen fertilization (HN)]. The results revealed that the leaf endophytic bacterial community was dominated by Gammaproteobacteria-affiliated families, such as Enterobacteriaceae and Xanthomonadaceae, which represent 28.7–86.8% and 2.14–42.6% of the total sequence reads, respectively, at all tested growth stages. The difference in the bacterial community structure between the different growth stages was greater than the difference resulting from the CO2 and nitrogen fertilization treatments. The eCO2 effect on the bacterial communities differed greatly under different nitrogen application conditions and at different growth stages. Specifically, eCO2 revealed a significant effect on the community structure under both LN and HN levels at the tillering stage; however, the significant effect of eCO2 was only observed under HN, rather than under the LN condition at the filling stage; no significant effect of eCO2 on the community structure at both the LN and HN fertilization levels was found at the maturity stage. These results provide useful insights into the response of leaf endophytic bacterial communities to elevated CO2 across rice growth stages.
    Frontiers in Microbiology 08/2015; 6. DOI:10.3389/fmicb.2015.00855 · 3.99 Impact Factor
  • Source
    • ". Establishment of very high population densities immediately after inoculation , but densities decline over time and distance from the inoculum source . Potential risks associated with the release into the environment . Unknown effect over native microbial communities . Bünemann et al . ( 2006 ) , Mabood et al . ( 2008 ) , Ryan et al . ( 2009 ) , Taghavi et al . ( 2009 ) , Friesen et al . ( 2011 ) , Bakker et al . ( 2012 ) , Chaparro et al . ( 2012 ) , Morel and Castro - Sowinski ( 2013 )"
    [Show abstract] [Hide abstract]
    ABSTRACT: The goal of microbiome engineering is to manipulate the microbiome toward a certain type of community that will optimize plant functions of interest. For instance, in crop production the goal is to reduce disease susceptibility, increase nutrient availability increase abiotic stress tolerance and increase crop yields. Various approaches can be devised to engineer the plant-microbiome, but one particularly promising approach is to take advantage of naturally evolved plant-microbiome communication channels. This is, however, very challenging as the understanding of the plant-microbiome communication is still mostly rudimentary and plant-microbiome interactions varies between crops species (and even cultivars), between individual members of the microbiome and with environmental conditions. In each individual case, many aspects of the plant-microorganisms relationship should be thoroughly scrutinized. In this article we summarize some of the existing plant-microbiome engineering studies and point out potential avenues for further research.
    Frontiers in Plant Science 07/2015; 6:507. DOI:10.3389/fpls.2015.00507 · 3.95 Impact Factor
  • Source
    • "sacchari IPT101, P. putida W619, and P. chlororaphis IMD555) which produced highest amount of PHA from mannitol, glucose and xylose were selected for further experiments using EGPJ. B. sacchari IPT101 and P. putida W619 were known for their ability to use mannitol for growth (Bramer et al., 2001; Taghavi et al., 2009) however, there are no reports on PHA production by these strains from mannitol. Growth and PHA accumulation by P. chlororaphis IMD555 with mannitol is reported for the first time in this study. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This study demonstrates the use of a mannitol rich ensiled grass press juice (EGPJ) as a renewable carbon substrate for polyhydroxyalkanoates (PHA) production in shaking flask experiments and fed-batch stirred tank reactor cultivations. Fed-batch cultivations of Burkholderia sacchari IPT101 using EGPJ as sole carbon source produced 44.5g/L CDW containing 33% polyhydroxybutyrate (PHB) in 36h, while Pseudomonas chlororaphis IMD555 produced a CDW of 37g/L containing 10% of medium chain length polyhydroxyalkanoates (mcl-PHA) in 34h. PHB and mcl-PHA extracted from B. sacchari IPT101 and P. chlororaphis IMD555, grown on EGPJ, had a molecular weight of 548kg/mol and 115.4kg/mol, respectively. While mcl-PHA can be produced from EGPJ, PHB production is more interesting as there is a 4-fold higher volumetric productivity compared to mcl-PHA. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Bioresource Technology 05/2015; 191:45-52. DOI:10.1016/j.biortech.2015.04.128 · 4.49 Impact Factor
Show more