Submitted to: International Conference on Mycorrhiza
Publication Type: Abstract Only
Publication Acceptance Date: 4/23/2003
Publication Date: 8/10/2003
Citation: GOVINDARAJULU, M., ABUBAKER, J., PFEFFER, P.E., ALLEN, J.W., BUCKING, H., LAMMERS, P.J., SHACHAR-HILL, Y. THE IDENTIFICATION AND EXPRESSION OF PUTATIVE HOMOLOGUES OF NITROGEN METABOLIC GENES IN GLOMUS INTRARADICES. INTERNATIONAL CONFERENCE ON MYCORRHIZA. 2003. ABSTRACT #268. P. 303.
Technical Abstract: Isotopic labeling and gene expression studies have revealed that hexose is the main carbon form obtained by the fungus from host plants, and that carbohydrate as well as lipid made from this is translocated to the ERM. To understand the extent by which these pathways are regulated at the transcriptional level in AM fungi, glucose was added to the mycorrhizal roots in split plate cultures that had no C-source on the ERM side. The timing and extent of C export to the ERM was measured by stable- and radio-isotopic labeling and quantitative real-time PCR was used to monitor the changes in gene expression in pathways involving glucose, trehalose, glycogen, and lipid metabolism after glucose addition. Gene expression levels were measured at 24, 48, 96, 144 hours after glucose addition relative to two reference genes: ribosomal protein and sidrophore regulatory protein. Following glucose addition to the mycorrhizal roots large amounts of C were exported to the ERM but this caused only modest expression changes of putative fungal homologues of malate synthase, glycogen synthase, acylCoA dehydrogenase, glucose-6-P dehydrogenase, and trehalase genes in IRM and ERM tissues.