Allantoin production and its utilization in relation to nodule formation in soybeans

Tajima, Shigeyuki; Yatazawa, Michihiko; Yamamoto, Yukio

doi:10.1080/00380768.1977.10433040

Cited by 38 publications

(22 citation statements)

References 13 publications

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“…Previous work (18,19) has shown that allantoinase is present in stem and leaf tissue, but prior to this report there has been no information on the presence of ureide-assimilating enzymes in soybean fruits. During leaf Plant Physiol.…”

Section: Discussionmentioning

confidence: 57%

“…In plants depending solely on N2 fixation for their N requirements, ureides comprise up to 86% of the xylem sap N (9). Based on enzymic studies, ureides were suggested to be synthesized in nodules and transported to the shoot where they are assimilated (18,19). Ishizuka (7) has suggested that ureide-N, arising predominantly from N2 fixation, is used more efficiently in seed protein production than N in the form of amino acids, amides and nitrate.…”

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confidence: 99%

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The Assimilation of Ureides in Shoot Tissues of Soybeans

Thomas¹,

Schrader²

1981

Plant Physiol.

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The ureide, alanton aNd alantoic acid, are major forns of N transported from nodules to shoots In soybeas (Merr.) The ureides, allantoin and allantoic acid, are found in abundance in soybeans (5,8,(10)(11)(12). In plants depending solely on N2 fixation for their N requirements, ureides comprise up to 86% of the xylem sap N (9). Based on enzymic studies, ureides were suggested to be synthesized in nodules and transported to the shoot where they are assimilated (18,19). Ishizuka (7) has suggested that ureide-N, arising predominantly from N2 fixation, is used more efficiently in seed protein production than N in the form of amino acids, amides and nitrate. The latter are the major forms of nitrogen exported from the roots when nitrate fertilizers are fed to plants (9).While ureides are known to accumulate in fruits and are thought to be utilized in seed protein production (7, 12), the enzymes involved in ureide assimilation (allantoinase, allantoicase and urease) have not been previously studied in soybean fruits. We know little about the assimilation of xylem-borne ureides in shoot tissue and the purpose of this paper is primarily to assess the capacity ofshoot tissue to assimilate allantoin via allantoinase and to describe the changes in enzyme activity during leaf and fruit development in nodulated soybeans. The amounts of ureides in plant tissues were also examined. Preparation of Plant Extracts. Extracts for the measurement of enzyme activity and ureide content were prepared by adding 7 ml ice-cold 0.05 M Tris-HCl buffer (pH 7.4) to 1 g fresh weight tissue and homogenizing in a Virtis 60 K homogenizer, speed setting 70, for 1 min. The homogenates were squeezed through four layers of cheesecloth and the filtrate centrifuged at 50,000g for 30 mm at 0 C. The resulting supernatants were used for the measurement of ureides; for measurements of enzyme activity the extracts were first desalted by passage through a Sephadex G-25 column (3). Extracts of leaves were prepared after removing the petioles and midrib veins, and when possible, fruits were separated into pods and seeds. Fruits developing at the eleventh to thirteenth nodes were used for enzyme extractions. The stem was cut into three sections: (a) from nodes 2 to 5; (b) nodes 6 to 9; and (c) nodes 10 to 14. The tissue from each section was separated into an outer green part (containing cortex, phloem and cambium) and an inner nongreen part (containing pith and xylem) by slicing the outer tissue with a razor blade and peeling it away from the inner tissue. Seeds were separated into seed coats, cotyledons, and embryos. After storage in a freezer (-20 C), seed coats and cotyledons were milled in a cyclone sample mill (Udy Analyzer Co., Boulder, CO). Embryos were not milled. Extracts of the separated seed parts were then prepared as described above.Measurement of Allantoinase Activity. The method used was basically that of Van Der Drift and Vogels (22) except that a substrate concentration of 25 mm was used. After 15 mm incubation at 30 C the reaction wa...

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Section: Discussionmentioning

confidence: 57%

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confidence: 99%

The Assimilation of Ureides in Shoot Tissues of Soybeans

Thomas¹,

Schrader²

1981

Plant Physiol.

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“…Work on the enzymes involved in purine degradation has been mainly studied in animals and micro-organisms with little emphasis on the occurrence, properties, and location of these enzymes in plants (Vogels and van der Drift, 1976). In particular there have been only a few reports of allantoic acid-degrading activity in plants (Echevin and Brunei, 1937;van der Drift and Vogels, 1966;Singh, 1968;Hartmann and Arnold, 1974;Tajima, Yatazawa, and Yamamoto, 1977). Following the work of Kushizaki, Ishizuka, and Akamatsu (1964) and Ishizuka, Okino, and Hoshi (1970) who showed that nodulated soyabean plants (Glycine max L.) contain large amounts of ureides, two Japanese groups have published evidence that nodules produce allantoin (Matsumoto, Yatazawa, and Yamamoto, 1977a;Fujihara and Yamaguchi, 1978a).…”

Section: Introductionmentioning

confidence: 99%

“…Following the work of Kushizaki, Ishizuka, and Akamatsu (1964) and Ishizuka, Okino, and Hoshi (1970) who showed that nodulated soyabean plants (Glycine max L.) contain large amounts of ureides, two Japanese groups have published evidence that nodules produce allantoin (Matsumoto, Yatazawa, and Yamamoto, 1977a;Fujihara and Yamaguchi, 1978a). From measurements of the enzymes involved in purine catabolism it was suggested that the allantoin is utilized mainly in the leaves after translocation (Tajima et al, 1977).…”

Section: Introductionmentioning

confidence: 99%

Ureide Metabolism in Non-nodulatedPhaseolus vulgarisL.

1980

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The distribution of ureide-N was studied throughout vegetative and reproductive growth of non-nodulated Phaseolus vulgaris L. (bushbean) grown in nitrate nutrient solution. Largest increases in ureide-N per plant were correlated with flowering and early pod formation and with seed filling. Highest amounts of ureides per organ were measured in stems and axillary trifoliates. Highest concentrations (jimo\ ureide-N g~' fr. wt) were measured in young developing organs and stems. Seeds did not accumulate ureides until the ureide content of pods had reached a maximum.Results obtained using the inhibitor of xanthine oxidase, allopurinol, are consistent with the origin of ureides via purine degradation but alternative pathways cannot be discounted.Leaves and stems were shown to have the ability to degrade allantoate via an enzymic process.

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“…In soybean nodules, uricase was reported to be located in the bacteroid away from the other purine oxidation enzymes (27) although the situation apparently was different in cowpea nodules (2). The location of uricase within the nodule tissue would undoubtedly prove to be important, since the pH and 02 requirements for optimum activity of this enzyme seem so different from the conditions which prevail generally in nodules (1,5).…”

Section: Discussionmentioning

confidence: 98%

Ureide Synthesis in a Cell-Free System from Cowpea (Vigna unguiculata [L.] Walp.) Nodules

Woo¹,

Atkins²,

Pate³

1981

Plant Physiol.

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Tbe effect of°2 and pH on the in vitro synthesis of IC-labeled ureides from IS-Clhypoxanthine in a cell free system from cowpea nodules was investigated. Under conditions which suppressed uricase (EC 1.733) activty, namely low 02 concentrations and low pH, ureide synthesis was inhibited and the 'C label incorporated into uric acid was increased. Conversely, conditos which increased uricase actinty, namelY high 02 concentrations and high pH, also stimulated ureide synthesis, and the 'C label was incorporated principaly into allantoin. The overal response of the system to 02 concentration and pH indicated that the per cent distribution of total 'C label incorporated into uric acid was inversely related to that into alantoi In the present study there was evidence that uricase (EC 1.733) controfled the in vitro rate of ureide synthesis in the cell-free system. Adenine and guanine inhibited xanthine dehydrogenase (EC 1.2.137) and as a consequence ureide synthesis from 18_14Clhypoxan-thine was also inhibited. MATERIALS AND METHODSAssays for ureide synthesis in the cytosolic fraction from cowpea nodules and the separation and identification of metabolic intermediates were carried out as previously described (33).Xanthine dehydrogenase (EC 1.2

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Allantoin production and its utilization in relation to nodule formation in soybeans

Cited by 38 publications

References 13 publications

The Assimilation of Ureides in Shoot Tissues of Soybeans

The Assimilation of Ureides in Shoot Tissues of Soybeans

Ureide Metabolism in Non-nodulatedPhaseolus vulgarisL.

Ureide Synthesis in a Cell-Free System from Cowpea (Vigna unguiculata [L.] Walp.) Nodules

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