Microbial transformation of Populus higher-order salicylates by microbiome isolates
J. MORRELL-FALVEY (1), D. Pelletier (2), G. Hurst (2), A. Bible (2), K. Chourey (2), M. Denney (3), K. Kertesz (3), A. Zinkle (2), C. Doktycz (2), C. Timm (2), S. Lu (2), N. Engle (2), T. Tschaplinski (2), M. Doktycz (2) (1) Oak Ridge National Laboratory, U.S.A.; (2) Oak Ridge National Laboratory, U.S.A.; (3) University of Tennessee, U.S.A.

Populus trees host a wide variety of microbial associations within their roots and rhizosphere and serve as a powerful model to study interactions between plants and microorganisms. One of the defining characteristics of Populus is the production of secondary metabolites known as higher-order salicylates (HOS), which are involved in host defense and signaling mechanisms. We are interested in determining how the presence and production of these HOS influence the host-microbiome composition and physiology. We have tested a number of bacteria from genera prevalent in the endosphere and rhizosphere compartments of Populus roots for their sensitivity to HOS and for the ability to utilize salicin, arbutin, and other HOS extracted from Populus tissues. To identify potential microbial mechanisms for transformation of HOS, we used proteomics to compare protein expression patterns of Pantoea sp. YR343 cells grown with glucose or salicin as the sole carbon source. Using these data, we identified several candidate gene products for further characterization. Further, we hypothesize that the complex nature of these HOS metabolites may lead to microbial cross feeding in the rhizosphere and this has been borne out in bacterial co-cultivation experiments. This analysis provides initial insight into the prevalence and diversity of Populus microbiota capable of transforming HOS, potential transformation mechanisms, and interactions between microbiome community members.

Abstract Number: P4-109
Session Type: Poster