Phosphatidylinositol 4-kinase activation is an early response to salicylic acid in Arabidopsis suspension cells.
Salicylic acid (SA) has a central role in defense against pathogen attack. In addition, its role in such diverse processes as germination, flowering, senescence, and thermotolerance acquisition has been documented. However, little is known about the early signaling events triggered by SA. Using Arabidopsis (Arabidopsis thaliana) suspension cells as a model, it was possible to show by in vivo metabolic phospholipid labeling with (33)P(i) that SA addition induced a rapid and early (in few minutes) decrease in a pool of phosphatidylinositol (PI). This decrease paralleled an increase in PI 4-phosphate and PI 4,5-bisphosphate. These changes could be inhibited by two different inhibitors of type III PI 4-kinases, phenylarsine oxide and 30 microm wortmannin; no inhibitory effect was seen with 1 microm wortmannin, a concentration inhibiting PI 3-kinases but not PI 4-kinases. We therefore undertook a study of the effects of wortmannin on SA-responsive transcriptomes. Using the Complete Arabidopsis Transcriptome MicroArray chip, we could identify 774 genes differentially expressed upon SA treatment. Strikingly, among these genes, the response to SA of 112 of them was inhibited by 30 microm wortmannin, but not by 1 microm wortmannin.
Krinke
Ondrej
O
Université Pierre et Marie Curie-Paris 6 and Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7180, Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Ivry-sur-Seine, France. ondrej.krinke@vscht.cz
Ruelland
Eric
E
Valentová
Olga
O
Vergnolle
Chantal
C
Renou
Jean-Pierre
JP
Taconnat
Ludivine
L
Flemr
Matyás
M
Burketová
Lenka
L
Zachowski
Alain
A
D019870:1-Phosphatidylinositol 4-Kinase / Q000378:metabolism*; D000730:Androstadienes; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D010716:Phosphatidylinositols / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D011401:Promoter Regions, Genetic; D020156:Salicylic Acid / Q000378:metabolism*; D000077191:Wortmannin
D000730:Androstadienes; D010716:Phosphatidylinositols; D010761:Phosphorus Radioisotopes; D019870:1-Phosphatidylinositol 4-Kinase; D020156:Salicylic Acid; D000077191:Wortmannin