Abstract
The radicle of the pea embryo (Pisum sativum L.) is known to possess a range of protein-degrading enzymes which could theoretically act in vivo to break down proteins stored in the radicle. However, most of the polypeptides of the radicle showed little evidence of net breakdown in vivo in the first 4 days from imbibition. One polypeptide, of mol. mass 13,000, was degraded almost completely between 1 and 2 days from imbibition; others, of mol. mass 84,000 and 30,000 were degraded within 4 days. The breakdown of polypeptides stored in the radicle (and plumule) is thus highly selective and closely regulated. The requirement for amino nitrogen in the growing axis is evidently met by the immediate export of amino acids from the cotyledons, rather than by massive breakdown of stored polypeptides in situ.
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Abbreviations
- ME:
-
2-mercaptoethanol
- SDS:
-
sodium dodecyl sulphate
- BSA:
-
bovine serum albumin
References
Bain, J.M., Mercer, F.V.: Subcellular organization of the cotyledons in germinating seeds and seedlings of Pisum sativum L. Aust. J. Biol. Sci. 19, 69–84 (1966a)
Bain, J.M., Mercer, F.V.: The relationship of the axis and the cotyledons in germinating seeds and seedlings of Pisum sativum L. Aust. J. Biol. Sci. 19, 85–96 (1966b)
Basha, S.M.M., Beevers, L.: The development of proteolytic activity and protein degradation during the germination of Pisum sativum L. Planta 124, 77–87 (1975)
Basha, S.M.M., Beevers, L.: Glycoprotein metabolism in the cotyledons of Pisum sativum during development and germination. Plant Physiol. 57, 93–97 (1976)
Beevers, L.: Protein degradation and proteolytic activity in the cotyledons of germinating pea seeds (Pisum sativum L.). Phytochemistry 7, 1837–1844 (1968)
Boulter, D., Thurman, D.A., Derbyshire, E.: A disc electrophoretic study of globulin proteins of legume seeds with reference to their systematics. New Phytol. 66, 27–36 (1967)
Guardiola, J.L., Sutcliffe, J.F.: Control of protein hydrolysis in the cotyledons of germinating pea (Pisum sativum L.) seeds. Ann. Bot. 35, 791–807 (1971)
Lawrence, J.M., Grant, D.R.: Nitrogen mobilization in pea seedlings II. Free amino acids. Plant Physiol. 38, 561–566 (1963)
Lawrence, J.M., Day, K.M., Stephenson, J.E.: Nitrogen mobilization in pea seedlings. Plant Physiol. 34, 668–674 (1959)
Millerd, A., Thomson, J.A., Schroeder, H.E.: Cotyledonary storage proteins in Pisum sativum. III. Patterns of accumulation during development. Aust. J. Plant Physiol. 5, 519–534 (1978)
Murray, D.R., Peoples, M.B., Waters, S.P.: Proteolysis in the axis of the germinating pea seed. I. Changes in protein degrading enzyme activities of the radicle and primary root. Planta 147, 111–116 (1979)
Perner, E.: Elektronenmikroskopische Untersuchungen an Zellen von Embryonen im Zustand völliger Samenruhe. II. Die Aleuronkörner in der Radicula lufttrockner Samen von Pisum sativum L. Planta 67, 324–343 (1965)
Thomson, J.A., Schroeder, H.E.: Cotyledonary storage proteins in Pisum sativum. II. Hereditary variation in components of the legumin and vicilin fractions. Aust. J. Plant Physiol. 5, 281–294 (1978)
Thomson, J.A., Schroeder, H.E., Dudman, W.F.: Cotyledonary storage proteins in Pisum sativum. I. Molecular heterogeneity. Aust. J. Plant Physiol. 5, 263–279 (1978)
Weber, K., Osborn, M.: The reliability of molecular weight determinations by dodecyl-sulfate-polyacrylamide gel electrophoresis. J. Biol. Chem. 244, 4406–4412 (1969)
Yomo, H., Varner, J.E.: Control of the formation of amylases and proteases in the cotyledons of germinating peas. Plant. Physiol. 51, 708–713 (1973)
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Murray, D.R. Proteolysis in the axis of the germinating pea seed. Planta 147, 117–121 (1979). https://doi.org/10.1007/BF00389510
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DOI: https://doi.org/10.1007/BF00389510