Allantoinase activity and ureide content of mesophyll and paraveinal mesophyll of soybean leaves

Costigan, Stephen A.; Franceschi, Vincent R.; Ku, Maurice S. B.

doi:10.1016/0168-9452(87)90072-0

Cited by 21 publications

(13 citation statements)

References 23 publications

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“…Ureides represent significant N storage forms in tropical legumes and are found in the stem, petiole, or leaf tissue (Herridge et al, 1978;Streeter, 1979). In leaves, ureide storage may occur in the vacuoles of mesophyll cells and, as shown for N-fixing soybean, to a larger extent in a specialized cell layer called paraveinal mesophyll, which is also a main site of protein storage during vegetative development (Franceschi & Giaquinta, 1983b;Costigan et al, 1987). However, transporters involved in vacuolar import and efflux of ureides have not yet been identified.…”

Section: Ureide Storagementioning

confidence: 99%

Source and sink mechanisms of nitrogen transport and use

2017

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Contents Summary35I.Introduction35II.Nitrogen acquisition and assimilation36III.Root‐to‐shoot transport of nitrogen38IV.Nitrogen storage pools in vegetative tissues39V.Nitrogen transport from source leaf to sink40VI.Nitrogen import into sinks42VII.Relationship between source and sink nitrogen transport processes and metabolism43VIII.Regulation of nitrogen transport43IX.Strategies for crop improvement44X.Conclusions46Acknowledgements47References47 Summary Nitrogen is an essential nutrient for plant growth. World‐wide, large quantities of nitrogenous fertilizer are applied to ensure maximum crop productivity. However, nitrogen fertilizer application is expensive and negatively affects the environment, and subsequently human health. A strategy to address this problem is the development of crops that are efficient in acquiring and using nitrogen and that can achieve high seed yields with reduced nitrogen input. This review integrates the current knowledge regarding inorganic and organic nitrogen management at the whole‐plant level, spanning from nitrogen uptake to remobilization and utilization in source and sink organs. Plant partitioning and transient storage of inorganic and organic nitrogen forms are evaluated, as is how they affect nitrogen availability, metabolism and mobilization. Essential functions of nitrogen transporters in source and sink organs and their importance in regulating nitrogen movement in support of metabolism, and vegetative and reproductive growth are assessed. Finally, we discuss recent advances in plant engineering, demonstrating that nitrogen transporters are effective targets to improve crop productivity and nitrogen use efficiency. While inorganic and organic nitrogen transporters were examined separately in these studies, they provide valuable clues about how to successfully combine approaches for future crop engineering.

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Section: Ureide Storagementioning

confidence: 99%

Source and sink mechanisms of nitrogen transport and use

2017

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“…Incorporation of storage nitrogen into ureides for export from the cotyledons could be important for energy conservation during early seedling establishment. Although it has not been established that ureides are exported from cotyledons, it is clear that shoot tissues can use ureides as a nitrogen source (Thomas and Schrader, 1981a;Costigan et al, 1987;Winkler et al, 1987). The importance of ureide metabolism in the overall nitrogen metabolism of seedlings remains to be established.…”

Section: Allantoinase In !Ieedsmentioning

confidence: 99%

Purification of Allantoinase from Soybean Seeds and Production and Characterization of Anti-Allantoinase Antibodies

Webb

Lindell

1993

Plant Physiol.

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Allantoinase catalyzes the hydrolysis of allantoin to allantoic acid, a reaction important in both biogenesis and degradation of ureides. Ureide production in cotyledons of germinating soybean (Glycine max 1.) seeds has not been studied extensively but may be important in mobilizing nitrogen reserves. Allantoinase was purified approximately 2500-fold from a crude extrad of soybean seeds by differential centrifugation, heat treatment, ammonium sulfate fractionation, ethanol fractionation, and fast protein liquid chromatography (Pharmacia) with Mono-Q and Superose columns. The purified enzyme had a subunit size of 30 kD. Polyclonal antibodies produced against the purified protein titrated allantoinase activity in a crude extract of seed proteins. Antibodies recognized the 30-kD band in western blot analysis of crude seed extracts, indicating that they were specific for allantoinase.

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“…) Here, next to the minor leaf veins where one would expect it, is a tissue that collects the reduced nitrogen (ureides) from the transpiration stream and stores them for redirection (Costigan, Franceschi & Ku, 1987). It is so intimately related to the bundle sheaths that we have proposed its name should be the extended bundle sheath (EBS) system (Kevekordes, McCully & Canny, 1988), and therefore ideally placed to scavenge from the veins.…”

Section: Solutes ~ Uptake Of Solutes From the Stream By Scavenging Cmentioning

confidence: 99%

Tansley Review No. 22 What becomes of the transpiration stream?

1990

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SUMMARY Changes of view on the course of the transpiration stream beyond the veins in leaves are followed from the imbibition theory of Sachs, through the (symplastic) endosmotic theory of Pfeffer (which prevailed almost unquestioned until the late 1930s), to Strugger's experiments with fluorescent dye tracers and the epifluorescence microscope. This latter work persuaded many to return to the apoplastic‐(wall)‐path viewpoint, which, despite early and late criticisms that were never rebutted, is still widely held. Tracer experiments of the same kind are still frequently published without consideration of the evidence that they do not reveal the paths of water movement. Experiments on rehydration kinetics of leaves have not produced unequivocal evidence for either path. The detailed destinies of the solutes that reach the leaf in the transpiration stream have received little attention. Consideration of physical principles governing flow and evaporation in a transpiring leaf emphasizes that: (1) Diffusion over interveinal distances at the rates in water will account for substantial solute movement in a few minutes, even in the absence of flow. (2) Diffusion can occur also against opposing now. (3) Volume fluxes in veins are determined by the diameter of the largest leaves examined contain high conductance supply veins which are tapped into by low‐conductance distributing veins. (4) Edges and teeth of leaves will be places of especially rapid evaporation, and they often have high‐conductance veins leading to them. (5) Solutes in the stream will tend to accumulate at leaf margins. On the basis of recent work, the view is maintained that the water of the stream enters the symplast through cell membranes very close to tracheary elements. Also, that this occurs locally over a small area of membrane. Many solutes in the stream are left outside in the apoplast. This produces regions of high solute concentration in the apoplast and an enrichment of solutes in the stream as it perfuses the leaf. Solutes that enter the symplast are not so easily tracked. Suggestions about where some of them may go can be gained from a fluorescent probe that identifies particular cells (scavenging cells) as having H+‐ATPase porter systems to scrub selected solutes from the stream. Unpublished case‐histories are presented which illustrate many aspects of these processes and principles. These are: (1) Maize leaf veins, where the symplastic water path starts at the parenchyma sheath; (2) Lupin veins, where the symplastic path starts at the bundle sheath and where solutes are concentrated in blind terminations; (3) The edges of maize leaves where flow is enhanced by a large vein (open to the apoplast), and solutes are deposited in the apoplast by evaporation; (4) Poplar leaf teeth, which receive strong flows, and where the epithem cells are scavenging cells; (5) Mimosa leaf marginal hairs, which have scavenging cells at their base; (6) Active hydathodes, whose epithem cells are scavenging cells; (7) Pine needle transfusion tissue, which is a site...

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Allantoinase activity and ureide content of mesophyll and paraveinal mesophyll of soybean leaves

Cited by 21 publications

References 23 publications

Source and sink mechanisms of nitrogen transport and use

Source and sink mechanisms of nitrogen transport and use

Purification of Allantoinase from Soybean Seeds and Production and Characterization of Anti-Allantoinase Antibodies

Tansley Review No. 22 What becomes of the transpiration stream?

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