Convergent pathways for lipochitooligosaccharide and auxin signaling in tobacco cells.
Lipochitooligosaccharides (LCOs) are a novel class of plant growth regulators that activate in tobacco protoplasts the expression of AXI1, a gene implicated in auxin signaling. Transient assays with a chimeric P(AXI)-GUS expression plasmid revealed that the N-octadecenoylated monosaccharide GlcN has all structural requirements for a biological active glycolipid, whereas the inactive N-acylated GalN epimer inhibits LCO action. Specific inhibition of LCO and auxin action shows that both signals are transduced within the tobacco cell via separate pathways that converge at or before AXI1 transcription. Cytokinin is suggested to be a common effector of LCO and auxin signaling. We also show that activation of AXI1 correlates with growth factor-induced cell division.
Röhrig
H
H
Max-Planck-Institut für Züchtungsforschung, Carl-von-Linné-Weg 10, D-50829 Köln, Germany.
Schmidt
J
J
Walden
R
R
Czaja
I
I
Lubenow
H
H
Wieneke
U
U
Schell
J
J
John
M
M
D029681:Arabidopsis Proteins / Q000235:genetics; D015152:Blotting, Northern; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D003583:Cytokinins / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D005966:Glucuronidase / Q000235:genetics; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000737:chemistry / Q000494:pharmacology*; D008957:Models, Genetic; D010937:Plant Growth Regulators / Q000737:chemistry / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011523:Protoplasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D014026:Nicotiana / Q000166:cytology; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection
D029681:Arabidopsis Proteins; D003583:Cytokinins; D007210:Indoleacetic Acids; D008070:Lipopolysaccharides; D010937:Plant Growth Regulators; D011993:Recombinant Fusion Proteins; C023023:lipid-linked oligosaccharides; D005966:Glucuronidase