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 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 Google Scholar Google Scholar Articles by Kasamo, K. Articles by Nouchi, I. Search for Related Content PubMed PubMed Citation Articles by Kasamo, K. Articles by Nouchi, I. Agricola Articles by Kasamo, K. Articles by Nouchi, I.

Membranes and Bioenergetics

The Role of Phospholipids in Plasma Membrane ATPase Activity in Vigna radiata L. (Mung Bean) Roots and Hypocotyls ¹

Department of Cell Biology, National Institute of Agrobiological Resources, Tsukuba Science City, Yatabe, Ibaraki 305, Japan, Division of Agrometeorology, National Institute of Agro-Environmental Sciences, P.O. Box 2, Yatabe-machi, Tsukuba-gun, Ibaraki 305, Japan

Root and hypocotyl plasma membrane H⁺-ATPases were partially purified from deoxycholate-solubilized fractions of microsomes in mung bean (Vigna radiata L.) plants in the presence of glycerol. Certain properties of the ATPases and the manner in which phospholipids affect their activity were compared. Root ATPase was similar to hypocotyl ATPase with respect to substrate specificity, salt stimulation, pH dependence, K_m for ATP·Mg²⁺ and inhibitor sensitivity, except for inhibition by vanadate. Both purified ATPases required phospholipids for their activation. Optimum concentrations of exogenously added phospholipid mixture (asolectin) to hypocotyl and root ATPase mixture were 0.03% and 1.0%, respectively. Root ATPase activation did not decrease if more than 1.0% asolectin was added. Qualitatively, phosphatidylserine and phosphatidylcholine brought about greater ATPase activation than other phospholipids. The hypocotyl ATPase was activated by phosphatidylinositol, phosphatidylserine and phosphatidylglycerol to a greater extent than the root ATPase. Root, but not hypocotyl ATPase, was slightly inhibited by the addition of phosphatidylinositol, phosphatidylethanolamine, and phosphatidic acid. The hypocotyl plasma membrane contained phosphatidylinositol + phosphatidylserine, phosphatidylglycerol and phosphatidic acid, and unsaturated fatty acids in greater abundance than the root plasma membrane. The differential activation of the plasma membrane ATPases may arise from these differences.

This article has been cited by other articles:

				F. Goubet and D. Mohnen Solubilization and Partial Characterization of Homogalacturonan-Methyltransferase from Microsomal Membranes of Suspension-Cultured Tobacco Cells Plant Physiology, September 1, 1999; 121(1): 281 - 290. [Abstract] [Full Text]