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 (51) Citing Articles via Google Scholar Google Scholar Articles by Winkler, R. G. Articles by Randall, D. D. Search for Related Content PubMed PubMed Citation Articles by Winkler, R. G. Articles by Randall, D. D. Agricola Articles by Winkler, R. G. Articles by Randall, D. D.

Metabolism and Enzymology

Ureide Catabolism of Soybeans ¹

II. Pathway of Catabolism in Intact Leaf Tissue

Interdisciplinary Plant Physiology and Biochemistry Group, University of Missouri, Columbia, Missouri 65211

Allantoin catabolism studies have been extended to intact leaf tissue of soybean (Glycine max L. Merr.). Phenyl phosphordiamidate, one of the most potent urease inhibitors known, does not inhibit ¹⁴CO₂ release from [2,7-¹⁴C]allantoin (urea labeled), but inhibits urea dependent CO₂ release 99.9% under similar conditions. Furthermore, ¹⁴CO₂ and [¹⁴C] allantoate are the only detectable products of [2,7-¹⁴C]allantoin catabolism. Neither urea nor any other product were detected by analysis on HPLC organic acid or organic base columns although urea and all commercially available metabolites that have been implicated in allantoin and glyoxylate metabolism can be resolved by a combination of these two columns. In contrast, when allantoin was labeled in the two central, nonureido carbons ([4,5-¹⁴C]allantoin), its catabolism to [¹⁴C]allantoate, ¹⁴CO₂, [¹⁴C]glyoxylate, [¹⁴C]glycine, and [¹⁴C]serine in leaf discs could be detected. These data are fully consistent with the metabolism of allantoate by two amidohydrolase reactions (neither of which is urease) that occur at similar rates to release glyoxylate, which in turn is metabolized via the photorespiratory pathway. This is the first evidence that allantoate is metabolized without urease action to NH₄⁺ and CO₂ and that carbons 4 and 5 enter the photorespiratory pathway.

This article has been cited by other articles:

				A. K. Werner, I. A. Sparkes, T. Romeis, and C.-P. Witte Identification, Biochemical Characterization, and Subcellular Localization of Allantoate Amidohydrolases from Arabidopsis and Soybean Plant Physiology, February 1, 2008; 146(2): 418 - 430. [Abstract] [Full Text] [PDF]

				C. D. Todd, P. A. Tipton, D. G. Blevins, P. Piedras, M. Pineda, and J. C. Polacco Update on ureide degradation in legumes J. Exp. Bot., January 1, 2006; 57(1): 5 - 12. [Abstract] [Full Text] [PDF]

				C. A. King and L. C. Purcell Inhibition of N2 Fixation in Soybean Is Associated with Elevated Ureides and Amino Acids Plant Physiology, April 1, 2005; 137(4): 1389 - 1396. [Abstract] [Full Text] [PDF]

				C. D. Todd and J. C. Polacco Soybean cultivars 'Williams 82' and 'Maple Arrow' produce both urea and ammonia during ureide degradation J. Exp. Bot., April 1, 2004; 55(398): 867 - 877. [Abstract] [Full Text] [PDF]

				T. R. Sinclair, V. Vadez, and K. Chenu Ureide Accumulation in Response to Mn Nutrition by Eight Soybean Genotypes with N2 Fixation Tolerance to Soil Drying Crop Sci., March 1, 2003; 43(2): 592 - 597. [Abstract] [Full Text] [PDF]

				V. Vadez and T. R. Sinclair Sensitivity of N2 Fixation Traits in Soybean Cultivar Jackson to Manganese Crop Sci., May 1, 2002; 42(3): 791 - 796. [Abstract] [Full Text] [PDF]

				A. Muñoz, P. Piedras, M. Aguilar, and M. Pineda Urea Is a Product of Ureidoglycolate Degradation in Chickpea. Purification and Characterization of the Ureidoglycolate Urea-Lyase Plant Physiology, February 1, 2001; 125(2): 828 - 834. [Abstract] [Full Text]

				V. Vadez and T. R. Sinclair Leaf ureide degradation and N2 fixation tolerance to water deficit in soybean J. Exp. Bot., January 1, 2001; 52(354): 153 - 159. [Abstract] [Full Text] [PDF]

				V. Vadez and T.R. Sinclair Ureide degradation pathways in intact soybean leaves J. Exp. Bot., August 1, 2000; 51(349): 1459 - 1465. [Abstract] [Full Text] [PDF]

				L. C. Purcell, C.A. King, and R. A. Ball Soybean Cultivar Differences in Ureides and the Relationship to Drought Tolerant Nitrogen Fixation and Manganese Nutrition Crop Sci., July 1, 2000; 40(4): 1062 - 1070. [Abstract] [Full Text]