Submitted to: International Conference on Mycorrhiza
Publication Type: Abstract Only
Publication Acceptance Date: 4/22/2003
Publication Date: 8/10/2003
Citation: BUCKING, H., ABUBAKER, J., GOVINDARAJULU, M., PFEFFER, P.E., LAMMERS, P., SHACHAR-HILL, Y. THE EFFECT OF ROOT EXUDATES ON SPORE GERMINATION, UPTAKE, METABOLISM AND GENE EXPRESSION OF THE ARBUSCULAR MYCORRHIZAL FUNGUS GLOMUS INTRARADICES. INTERNATIONAL CONFERENCE ON MYCORRHIZA. 2003. ABSTRACT #239. P. 282.
Technical Abstract: Arbuscular mycorrhizal (AM) fungi are obligate biotrophic root symbionts that show only limited hyphal development in the absence of a host plant. The developmental stages involved in establishing the symbiosis include spore germination, hyphal branching, appressorium development and formation of arbuscules and of an extraradical mycelium. This developmental program requires signaling and recognition between partners, and the roots of host plants constitutively secrete compounds that stimulate ramifications in hyphae from germinating spores. We are using stereomicroscopy, isotopic labeling and real-time quantitative PCR to address the effects of exudates of Ri T-DNA transformed carrot roots on germination, on the uptake and metabolism of exogenous substrates and on the expression of genes putatively encoding key enzymes of central metabolism in Glomus intraradices. Root exudates supplied to AM fungal spores in various concentrations significantly affect germination, hyphal branching, uptake and metabolism of carbon substrates in these spores. The implications for signaling, development and the potential for axenic culture will be discussed.