Submitted to: International Conference on Mycorrhiza
Publication Type: Abstract Only
Publication Acceptance Date: 4/21/2003
Publication Date: 8/10/2003
Citation: ABUBAKER, J., GOVINDARAJULU, M., PFEFFER, P.E., BUCKING, H., LAMMERS, P.J., SHACHAR-HILL, Y. THE EFFECTS OF GLUCOSE ON CARBON METABOLISM IN GLOMUS INTRARADICES DURING ARBUSCULAR MYCORRHIZAL SYMBIOSIS. INTERNATIONAL CONFERENCE ON MYCORRHIZA. 2003. ABSTRACT #269. P. 304.
Technical Abstract: The mechanisms and regulation of nitrogen assimilation and transport in AM fungi are not well understood. To test hypotheses about the uptake, transformation and transfer of N we are taking a dual approach using stable isotope labeling, gene identification and expression measurements. We identified several potential genes of primary nitrogen metabolism in Glomus intraradices by mining the expressed sequence tag (EST) databases and by PCR amplification using multiple alignments of fungal protein sequences to create degenerate primers. Using a sterile in vitro split plate culture system, mycorrhizal roots and extrararadical mycelium (ERM) were exposed to different forms and levels of N, and the resultant pattern of fungal gene expression was analyzed by quantitative real-time PCR. Expression of these genes in both intraradical and extraradical tissues was found to be rather responsive to the forms and levels of external nitrogen. We will also report on the results of stable isotope labeling experiments designed to determine the form(s) of nitrogen translocated within the AM fungal mycelium and transferred to the host plant.