The potential signalling pathways which regulate surface changes induced by phytohormones in the potato cyst nematode (Globodera rostochiensis).
It has been demonstrated that the surface lipophilicity of the plant-parasitic nematode Globodera rostochiensis decreases when infective larvae are exposed to the phytohormones indole-3-acetic acid (auxin) or kinetin (cytokinin). In the present study, it was shown that inhibition of phospholipase C (PLC) or phosphatidylinositol 3 kinase (PI3-kinase) reversed the effect of phytohormones on surface lipophilicity. The signalling pathway(s) involved in surface modification were investigated using 'caged' signalling molecules and stimulators or inhibitors of different signalling enzymes. Photolysis of the 'caged' signalling molecules, NPE-caged Ins 1,4,5-P3, NITR-5/AM or caged-cAMP to liberate IP3, Ca2+ or cAMP respectively, decreased the surface lipophilicity. Activation of adenylate cyclase also decreased the surface lipophilicity. In contrast, inhibition of PI3-kinase using Wortmannin, LY-294002 or Quercetin, and inhibition of PLC using U-73122 all increased the surface lipophilicity. Two possible signalling pathways involved in phytohormone-induced surface modification are proposed.
Akhkha
A
A
Davidson Building, Division of Biochemistry and Molecular Biology, University of Glasgow, Glasgow G12 8QQ, UK. a.akhkha@bio.gla.ac.uk
Curtis
R
R
Kennedy
M
M
Kusel
J
J
D000225:Adenine / Q000031:analogs & derivatives / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors / Q000502:physiology; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007210:Indoleacetic Acids / Q000502:physiology*; D015544:Inositol 1,4,5-Trisphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D007701:Kinetin; D008856:Microscopy, Fluorescence; D009348:Nematoda / Q000502:physiology*; D009349:Nematode Infections / Q000469:parasitology*; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010935:Plant Diseases / Q000469:parasitology*; D015398:Signal Transduction / Q000502:physiology; D011198:Solanum tuberosum / Q000469:parasitology*; D013499:Surface Properties / Q000187:drug effects; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000502:physiology
D000225:Adenine; D000255:Adenosine Triphosphate; D002118:Calcium; D002614:Chelating Agents; D004533:Egtazic Acid; D004791:Enzyme Inhibitors; D007210:Indoleacetic Acids; D015544:Inositol 1,4,5-Trisphosphate; D007701:Kinetin; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010738:Type C Phospholipases; C052455:nitr 5; C061868:inositol 1,4,5-trisphosphate 1-(2-nitrophenyl)ethyl ester; C029273:P(3)-1-(2-nitro)phenylethyladenosine 5'-triphosphate