PLANT PHYSIOLOGY , Vol 104, Issue 1 49-57, Copyright © 1994 by American Society of Plant Biologists

METABOLISM AND ENZYMOLOGY

Purification of the Major Soybean Leaf Acid Phosphatase That Is Increased by Seed-Pod Removal

P. E. Staswick, C. Papa, J. F. Huang and Y. Rhee
Department of Agronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68583-0915

Fruit removal for 5 weeks after flowering increased acid phosphatase activity 10-fold in soybean (Glycine max L. Merr. Var Hobbit) leaves compared with normal seed-pod-bearing plants. The major acid phosphatase activity in leaves was purified over 2700-fold, yielding a single polypeptide of 51 kD with a specific activity of 1353 units/mg protein using p-nitrophenylphosphate as the substrate. Isoelectric focusing demonstrated that the purified protein co-migrated with a majority of the activity that increased in leaves following seed-pod removal. Immunoblot analysis demonstrated that at least part of the increased activity was due to an increased abundance of the phosphatase protein. In situ enzyme activity staining localized most of the total phosphatase activity to vascular tissues, the leaf paraveinal mesophyll cell layer, and the lower epidermis. This distribution and the response to seed-pod removal paralleled previous results for soybean vegetative storage protein (VSP) [alpha] and [beta]. However, in a native polyacrylamide gel the VSP detected by immunological staining of electrophoretically transferred protein did not migrate with the majority of the phosphatase activity. Fractionation of crude leaf protein on concanavalin A-Sepharose yielded a fraction containing 97% of the total VSP but only 0.1% of the total acid phosphatase activity.

This article has been cited by other articles:

				J. L. Tomscha, M. C. Trull, J. Deikman, J. P. Lynch, and M. J. Guiltinan Phosphatase Under-Producer Mutants Have Altered Phosphorus Relations Plant Physiology, May 1, 2004; 135(1): 334 - 345. [Abstract] [Full Text] [PDF]

				M. Miranda, L. Borisjuk, A. Tewes, D. Dietrich, D. Rentsch, H. Weber, and U. Wobus Peptide and Amino Acid Transporters Are Differentially Regulated during Seed Development and Germination in Faba Bean Plant Physiology, August 1, 2003; 132(4): 1950 - 1960. [Abstract] [Full Text] [PDF]

				P. E. Staswick, Z. Zhang, T. E. Clemente, and J. E. Specht Efficient Down-Regulation of the Major Vegetative Storage Protein Genes in Transgenic Soybean Does Not Compromise Plant Productivity Plant Physiology, December 1, 2001; 127(4): 1819 - 1826. [Abstract] [Full Text] [PDF]

				C. Ji, C. Boyd, D. Slaymaker, Y. Okinaka, Y. Takeuchi, S. L. Midland, J. J. Sims, E. Herman, and N. Keen Characterization of a 34-kDa soybean binding protein for the syringolide elicitors PNAS, March 17, 1998; 95(6): 3306 - 3311. [Abstract] [Full Text] [PDF]