title: The oleate-stimulated phospholipase D, PLDdelta, and phosphatidic acid decrease H2O2-induced cell death in Arabidopsis.
abstract: Hydrolysis of common membrane phospholipids occurs in response to various environmental stresses, but the control and cellular function of this hydrolysis are not fully understood. Hydrogen peroxide (H2O2) is a pivotal signaling molecule involved in various stress responses. Here, we show that the plasma membrane-bound phospholipase D, PLDdelta, is activated in response to H2O2 and that the resulting phosphatidic acid (PA) functions to decrease H2O2-promoted programmed cell death. The Arabidopsis genome has 12 PLD genes, and knockout of PLDdelta abolishes specifically the oleate-stimulated PLD activity. H2O2 treatment of Arabidopsis cells activates PLD enzyme activity, and ablation of PLDdelta abolishes that activation. PLDdelta-null cells display increased sensitivity to H2O2-induced cell death. The addition of PA to PLDdelta-null cells mitigates the H2O2 effect, whereas suppression of the H2O2-induced PA formation in wild-type cells increases the effect. PLDdelta-ablated plants exhibit increased susceptibility to stress. These results demonstrate that activation of oleate-stimulated PLDdelta constitutes an important step in the plant response to H2O2 and increasing plant stress tolerance.
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D017360:Arabidopsis / Q000166:cytology / Q000201:enzymology* / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000187:drug effects / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects*; D004789:Enzyme Activation; D017353:Gene Deletion; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008954:Models, Biological; D019301:Oleic Acid / Q000494:pharmacology*; D010712:Phosphatidic Acids / Q000378:metabolism*; D010739:Phospholipase D / Q000187:drug effects / Q000378:metabolism*; D010740:Phospholipases / Q000187:drug effects / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D010712:Phosphatidic Acids; D019301:Oleic Acid; D006861:Hydrogen Peroxide; D010740:Phospholipases; C446530:phospholipase D delta; D010739:Phospholipase D