Mighty duckweeds: growth promoting microbes associated with an aquatic plant
S. LEBEIS (1), E. Lam (2), K. McGuire (1), S. Gilbert (2) (1) University of Tennessee, U.S.A.; (2) Rutgers University, U.S.A.

While several mechanisms utilized by beneficial microbes associated with terrestrial plants have been characterized, less is known about how microbes affect aquatic plant growth. We hypothesized that such beneficial relationships also exist for aquatic plants in the family Lemnaceae, comm known as duckweeds. Duckweed is the fastest growing flowering plant, and holds potential to be used for phytoremediation of wastewater by extracting carbon, nitrogen, and phosphorus. Further, duckweed is easily harvested, and can be used as biomass for biofuel production. We performed massive parallel sequencing of duckweed grown in from a municipal wastewater treatment plant, as well as water controls to determine the assembled microbes from the aquatic environment. Further, we have built a collection of isolated endophytic bacteria from natural duckweed ecotypes. In order to determine the potential molecular mechanisms for growth promotion phenotypes, we elected to screen our duckweed-terrestrial plant, Arabidopsis thaliana. Among the duckweed-associated microbes screen, a Micrococcus sp. colonizes the endophytic compartment dramatically altering root morphology of A. thaliana, probably via auxin production. We will use the remainder of our isolate collection to define other such growth promotion mechanisms. These studies in duckweed will set the stage for deployment of defined microbial amendments to optimize farming of these aquatic plants for renewable biomass production.

Abstract Number: C10-1
Session Type: Concurrent