Metabolic consequences of the introduction of a Populus trichocarpa lectin receptor-like kinase into Arabidopsis thaliana, a non-ectomycorrhizal host species
T. TSCHAPLINSKI (1), Z. Zhang (2), J. Labbe (2), W. Muchero (2), Y. Yang (2), P. Ranjan (3), S. Jawdy (2), G. Tuskan (2), J. Chen (2) (1) Oak Ridge National Laboratory, U.S.A.; (2) Oak Ridge National Laboratory, U.S.A.; (3) University of Tennessee, U.S.A.

A lectin receptor-like kinase (LecRLK) was identified in Populus trichocarpa that was demonstrated to facilitate the initiation of a symbiotic ectomycorrhizal association with Laccaria bicolor. This Populus LecRLK was introduced via genetic transformation into Arabidopsis thaliana, a non-ectomycorrhizal host species, and the resulting metabolomic profiles of transgenic plants were determined by gas chromatography-mass spectrometry and contrasted with wild-type plants. Given that this Populus LecRLK is predicted to bind mannose, the metabolomic profiles of plants with and without the LecRLK gene were grown with and without a short-term (4 h) mannose addition versus a glucose addition. In a study conducted in parallel, the effects of transgene insertion on the metabolomic profiles were determined in the presence and absence of L. bicolor, a Populus fungal symbiont. The presence of the LecRLK alone in the non-host species resulted in a large-scale restructuring of the plant metabolome, as evidenced by the 9 to 29-fold accumulations of defense metabolites sinapoylmalate, kaempferol, and quercetin. Interestingly, there were concomitant declines in a number of fatty acids and amino acids that are often attributed to utilization by the fungal symbiont. The presence of mannose in the media intensified the declines in these classes of metabolites, and many of these responses were evident in the non-host species when grown in the presence of L. bicolor, but the responses were again more intense when the fungus was present. The consequences of the metabolic reprogramming that are driven by this Populus LecRLK gene versus that induced by the fungal associate will be discussed.

Abstract Number: C7-4, P1-9
Session Type: Concurrent