Mycorrhizal phosphate uptake pathway in tomato is phosphorus-repressible and transcriptionally regulated.
Plants colonized by arbuscular mycorrhizal (AM) fungi take up phosphate (Pi)via the mycorrhizal and the direct Pi uptake pathway. Our understanding of the molecular mechanisms involved in the regulation of these pathways is just emerging.Here, we have analyzed the molecular physiology of mycorrhizal Pi uptake in the tomato (Solanum lycopersicum) variety Micro-Tom and integrated the data obtained with studies on chemical signaling in mycorrhiza-inducible Pi transporter gene regulation.At high plant phosphorus (P) status, the mycorrhizal Pi uptake pathway was almost completely repressed and the mycorrhiza-inducible Pi transporter genes were down-regulated. A high plant P status also suppressed the activation of the mycorrhiza-specific StPT3 promoter fragment by phospholipid extracts containing the mycorrhiza signal lysophosphatidylcholine.Our results suggest that the mycorrhizal Pi uptake pathway is controlled at least partially by the plant host. This control involves components in common
Nagy
Réka
R
Federal Institute of Technology (ETH) Zurich, Institute of Plant Sciences, Experimental Station Eschikon 33, CH-8315 Lindau, Switzerland.
Drissner
David
D
Federal Institute of Technology (ETH) Zurich, Institute of Plant Sciences, Experimental Station Eschikon 33, CH-8315 Lindau, Switzerland.
Amrhein
Nikolaus
N
Federal Institute of Technology (ETH) Zurich, Institute of Plant Sciences, Universitätstrasse 2, CH-8092 Zurich, Switzerland.
Jakobsen
Iver
I
National Laboratory for Sustainable Energy (Risø DTU), Technical University of Denmark, Biosystems Department, Frederiksborgvej 399, DK-4000 Roskilde, Denmark.
Bucher
Marcel
M
Federal Institute of Technology (ETH) Zurich, Institute of Plant Sciences, Experimental Station Eschikon 33, CH-8315 Lindau, Switzerland.|Present address: University of Cologne, Institute of Botany, Gyrhofstrasse 15, D-50931 Cologne, Germany.
D001692:Biological Transport; D018551:Solanum lycopersicum / Q000378:metabolism / Q000382:microbiology*; D008244:Lysophosphatidylcholines / Q000378:metabolism; D038821:Mycorrhizae / Q000378:metabolism*; D028061:Phosphate Transport Proteins / Q000235:genetics / Q000502:physiology; D010710:Phosphates / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics
D008244:Lysophosphatidylcholines; D028061:Phosphate Transport Proteins; D010710:Phosphates; D010940:Plant Proteins; D010758:Phosphorus