Poplar Roots Influence Microbial Community Composition


Poplar, a model organism for woody perennials, is a promising bioenergy feedstock for producing cellulosic biofuels. Poplar roots establish intimate associations with various microorganisms, both bacterial and fungal, that are beneficial to both plant and microbe. However, these associations are still poorly understood. Researchers at Oak Ridge National Laboratory have published the first results of a comprehensive study of the poplar rhizosphere (soil in direct contact with plant roots) and endophytic (living within plant tissues without causing harm) microbial communities from mature, natural poplar stands. They investigated microbial diversity among root endophyte and associated rhizosphere communities from two poplar populations differing in soil and stand characteristics near the Caney Fork River in central Tennessee. Although soil was not a major determinant of microbial distribution and diversity, the rhizosphere and endophyte communities of both bacteria and fungi were distinct. The results suggest that tissues within naturally occurring poplar roots provide a unique niche for these microorganisms. The research has implications for the growth and management of poplar plantations established for biofuel production.


Gottel, N. R., H. F. Castro, M. Kerley, Z. Yang, D. A. Pelletier, M. Podar, T. Karpinets, E. Uberbacher, G. A. Tuskan, R. Vilgalys, M. J. Doktycz, and C. W. Schadt. 2011. “Distinct Microbial Communities Within the Endosphere and Rhizosphere of Populus deltoides Roots Across Contrasting Soil Types,” Applied and Environmental Microbiology 77(17), 5934-44. (DOI:10.1128/AEM.05255-11)