Auxin-induced reactive oxygen species production requires the activation of phosphatidylinositol 3-kinase.
We recently reported that production of reactive oxygen species (ROS) is essential for auxin-induced gravitropic signaling. Here, we investigated the role of phosphatidylinositol 3-kinase and its product, PtdIns(3)P, in auxin-mediated ROS production and the root gravitropic response. Pretreatment with LY294002, an inhibitor of PtdIns 3-kinase activity, blocked auxin-mediated ROS generation, and reduced the sensitivity of root tissue to gravistimulation. The amount of PtdIns(3)P increased in response to auxin, and this effect was abolished by pretreatment with LY294002. In addition, sequestration of PtdIns(3)P by transient expression of the endosome binding domain in protoplasts abrogated IAA-induced ROS accumulation. These results indicate that activation of PtdIns 3-kinase and its product PtdIns(3)P are required for auxin-induced production of ROS and root gravitropism.
Joo
Jung Hee
JH
Division of Molecular Life Science, Center for Cell Signaling Research, Ewha Womans University, Seoul 120-750, Korea.
Yoo
Ho Jung
HJ
Hwang
Inhwan
I
Lee
June Seung
JS
Nam
Kyoung Hee
KH
Bae
Yun Soo
YS
D000730:Androstadienes / Q000494:pharmacology; D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D002867:Chromones / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D018522:Gravitropism; D007210:Indoleacetic Acids / Q000494:pharmacology*; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D000077191:Wortmannin; D003313:Zea mays / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism
D000730:Androstadienes; D002867:Chromones; D007210:Indoleacetic Acids; D009025:Morpholines; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D019869:Phosphatidylinositol 3-Kinases; D000077191:Wortmannin