Phosphate uptake, transport and transfer by the arbuscular mycorrhizal fungus Glomus intraradices is stimulated by increased carbohydrate availability
Article first published online: 17 JAN 2005
Volume 165, Issue 3, pages 899–912, March 2005
How to Cite
Bücking, H. and Shachar-Hill, Y. (2005), Phosphate uptake, transport and transfer by the arbuscular mycorrhizal fungus Glomus intraradices is stimulated by increased carbohydrate availability. New Phytologist, 165: 899–912. doi: 10.1111/j.1469-8137.2004.01274.x
- Issue published online: 17 JAN 2005
- Article first published online: 17 JAN 2005
- Received: 20 August 2004 Accepted: 21 September 2004
- arbuscular mycorrhiza;
- Glomus intraradices;
- nutrient exchange;
- • The influence of carbohydrate availability to mycorrhizal roots on uptake, metabolism and translocation of phosphate (P) by the fungus was examined in axenic cultures of transformed carrot (Daucus carota) roots in symbiosis with Glomus intraradices.
- • 14C-labelled carbohydrates, 33P-phosphate and energy dispersive X-ray microanalysis were used to follow the uptake and transfer of C and P in the arbuscular mycorrhizal (AM) symbiosis.
- • The uptake of P by the extraradical mycelium (ERM) and its translocation to the mycorrhizal roots was stimulated and the metabolic and spatial distribution of P within the fungus were altered in response to increased carbohydrate availability. Sucrose supply resulted in a decrease of polyphosphates and an increased incorporation into phospholipids and other growth-related P pools and also caused elevated cytoplasmic P levels in the intraradical mycelium (IRM) within the root and higher cytoplasmic P levels in the root cortex.
- • These findings indicate that the uptake of P by the fungus and its transfer to the host is also stimulated by the transfer of carbon from plant to fungus across the mycorrhizal interface.