The Oleate-Stimulated Phospholipase D, PLDδ, and Phosphatidic Acid Decrease H₂O₂-Induced Cell Death in Arabidopsis

• Published in: The Plant cell Vol. 15; no. 10; pp. 2285 - 2295
• Main Authors: Zhang, Wenhua, Wang, Cunxi, Qin, Chunbo, Wood, Tara, Olafsdottir, Gudrun, Welti, Ruth, Wang, Xuemin
• Format: Journal Article
• Language: English
• Published: American Society of Plant Biologists 01-10-2003
• Subjects: Cell death; Cell membranes; Hydrolysis; Leaves; Lipids; Phosphatidic acids; Phospholipids; Plant cells; Plants; Protoplasts
• ISSN: 1040-4651; 1532-298X
• DOI: 10.1105/tpc.013961

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 ( H2 O2) is a pivotal signaling molecule involved in various stress responses. Here, we show that the plasma membrane-bound phospholipase D, PLDδ, is activated in response to H2 O2 and that the resulting phosphatidic acid (PA) functions to decrease ${\rm H}_{2}{\rm O}_{2}\text{-promoted}$ programmed cell death. The Arabidopsis genome has 12 PLD genes, and knockout of PLDδ abolishes specifically the oleate-stimulated PLD activity. H2 O2 treatment of Arabidopsis cells activates PLD enzyme activity, and ablation of PLDδ abolishes that activation. PLDδ-null cells display increased sensitivity to H2 O2-induced cell death. The addition of PA to PLDδ-null cells mitigates the H2 O2 effect, whereas suppression of the H2 O2-induced PA formation in wild-type cells increases the effect. PLDδ-ablated plants exhibit increased susceptibility to stress. These results demonstrate that activation of oleate-stimulated PLDδ constitutes an important step in the plant response to H2 O2 and increasing plant stress tolerance.