This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (25) Citing Articles via Google Scholar Google Scholar Articles by Brightman, A. O. Articles by Morré, D. J. Search for Related Content PubMed PubMed Citation Articles by Brightman, A. O. Articles by Morré, D. J. Agricola Articles by Brightman, A. O. Articles by Morré, D. J.

Development and Growth Regulation

Activation of Plasma Membrane NADH Oxidase Activity by Products of Phospholipase A

Department of Medicinal Chemistry and Pharmacognosy, Purdue University, West Lafayette, Indiana 47907

An auxin-stimulated NADH oxidase activity (NADH oxidase I) of plasma membrane vesicles, highly purified by aqueous two-phase partition from soybean (Glycine max Merr.) hypocotyls was activated by lysophospholipids and fatty acids, both products of phospholipase A action. The activation of NADH oxidase activity occurred slowly, suggesting a mechanism whereby the lipids acted to stabilize the enzyme in a more active configuration. In contrast to activation by lipids, the activation by auxin was rapid. The average K_m of the NADH oxidase after activation by lipids was four- to fivefold less than the K_m before activation. The V_max was unchanged by activation. The increases occurred in the presence of detergent and thus were not a result of exposure of latent active sites. Also, the activation did not result from activation of a peroxidase or lipoxygenase. Fatty acid esters, where growth promoting effects have been reported, also activated the auxin-stimulated oxidase. However, the auxin stimulation of NADH oxidase I did not appear to be obligatorily mediated by phospholipase A, nor did inhibitors of phospholipase A₂ block the stimulation of the oxidase by auxins.

This article has been cited by other articles:

				H. Y. Lee, S. C. Bahn, Y.-M. Kang, K. H. Lee, H. J. Kim, E. K. Noh, J. P. Palta, J. S. Shin, and S. B. Ryu Secretory Low Molecular Weight Phospholipase A2 Plays Important Roles in Cell Elongation and Shoot Gravitropism in Arabidopsis PLANT CELL, September 1, 2003; 15(9): 1990 - 2002. [Abstract] [Full Text] [PDF]

				J. Narváez-Vásquez, J. Florin-Christensen, and C. A. Ryan Positional Specificity of a Phospholipase A Activity Induced by Wounding, Systemin, and Oligosaccharide Elicitors in Tomato Leaves PLANT CELL, November 1, 1999; 11(11): 2249 - 2260. [Abstract] [Full Text]

				D J Morre A protein disulfide-thiol interchange protein with NADH: protein disulfide reductase (NADH oxidase) activity as a molecular target for low levels of exposure to organic solvents in plant growth Human and Experimental Toxicology, May 1, 1998; 17(5): 272 - 277. [Abstract] [PDF]

				U. Ståhl, B. Ek, and S. Stymne Purification and Characterization of a Low-Molecular-Weight Phospholipase A2 from Developing Seeds of Elm Plant Physiology, May 1, 1998; 117(1): 197 - 205. [Abstract] [Full Text]