title: Activation of phospholipase D induced by hydrogen peroxide in suspension-cultured rice cells.
abstract: Hydrogen peroxide (H2O2) (10-100 microM) induced rapid and transient accumulation of phosphatidic acid (PA) in suspension-cultured rice cells. When phospholipase activity in the cellular extract fraction prepared from rice cells treated with H2O2 was assayed in the presence of 1-butanol (0.1%), rapid and transient phosphatidylbutanol (PtdBut) formation was observed. Thus, the H2O2-activated phospholipase was concluded to be phospholipase D (PLD). Furthermore, H2O2 directly induced in vitro PLD activation in the cytosolic fraction without H2O2 treatment. In vitro and in vivo activation of PLD were completely suppressed in the presence of lavendustin A (0.05 mM), a potent inhibitor of protein tyrosine kinase. Phytoalexin biosynthesis induced by N-acetylchitooligosaccharide elicitor was enhanced in the presence of H2O2 (10-100 microM), whereas it was suppressed in the presence of tiron, a potent scavenger of O2-, 1-butanol (0.1%) and lavendustin A (0.05 mM). These results indicate that H2O2-inducible PLD activation enhances signal transduction leading to phytoalexin biosynthesis in rice cells.
authors.affiliation: Department of Rice Research, National Agricultural Research Center, National Agricultural and Bio-oriented Research Organization, Joetsu, Niigata, 943-0193 Japan. tkyama@affrc.go.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tanabe
authors.forename: Eiichi
authors.initials: E
authors.lastname: Minami
authors.forename: Naoto
authors.initials: N
authors.lastname: Shibuya
mesh_terms: D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt / Q000494:pharmacology; D020001:1-Butanol / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D002478:Cells, Cultured; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D012275:Oryza / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D010636:Phenols / Q000494:pharmacology; D010739:Phospholipase D / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors
chemical_list: D004791:Enzyme Inhibitors; D010636:Phenols; C062898:lavendustin A; D014013:1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium Salt; D020001:1-Butanol; D006861:Hydrogen Peroxide; D011505:Protein-Tyrosine Kinases; D010739:Phospholipase D