Abstract
The timing of changes in total nitrogen and soluble amino nitrogen content, and in the activities of proteinase (pH 7.0), isocitrate lyase, catalase, phytase, phosphatase (pH 5.0), α-galactosidase and β-mannosidase were studied in extracts from the cotyledons, axis and endosperms of germinating and germinated light-promoted lettuce seeds. The largest amount of total nitrogen (2.7% seed dry weight) occurs within the cotyledons, as storage protein. As this decreases the total nitrogen content of the axis increases and the soluble amino nitrogen in the cotyledons and axis increases. Proteinase activity in the cotyledons increases coincidentally with the depletion of total nitrogen therein. Enzymes for phytate mobilisation and for gluconeogenesis of hydrolysed lipids increase in activity in the cotyledons as the appropriate stored reserves decline. Beta-mannosidase, an enzyme involved in the hydrolysis of oligo-mannans released by the action of endo-β-mannase on mannan reserves in the endosperm, arises within the cotyledons. This indicates that complete hydrolysis of mannans to the monomer does not occur within the endosperm. Mobilisation of all cotyledon reserves occurs after the endosperm has been degraded, providing further evidence that the endosperm is an early source of food reserves for the growing embryo.
Similar content being viewed by others
Abbreviations
- HEPES:
-
N-2-hydroxyethylpiperazine-N′-2-ethanesulphonic acid
- EDTA:
-
ethylenediamine tetraacetic acid disodium salt
- TCA:
-
trichloroacetic acid
References
Bewley, J.D., Black, M.: Physiology and biochemistry of seeds in relation to germination. I. Development, germination and growth. Berlin, Heidelberg, New York: Springer 1978
Chance, B., Maehly, A.C.: Assay of catalases and peroxidases. In: Methods in Enzymology, vol. 11, pp. 764–775, Colowick, S.P., Kaplan, N.O., eds. New York: Academic Press 1955
Dixon, G.H., Kornberg, H.L.: Assay methods for key enzymes of glyoxylate cycle. Biochem. J. 72 (1959)
Eldan, M., Mayer, A.M., Poljakoff-Mayber, A., Eldan, M.: Difference in subcellular localisation of isocitrate lyase in lettuce seeds of different ages. Plant Cell Physiol. 15, 169–173 (1974)
Griffiths, A.E.: Observations on the germination of lttuce seed. Contrib. Boyce Thompson Inst. 9, 329–337 (1938)
Halmer, P., Bewley, J.D.: Mannase production by the lettuce endosperm. Control by the embryo. Planta 144, 333–340 (1978)
Halmer, P., Bewley, J.D., Thorpe, T.A.: An enzyme to break down lettuce endosperm during gibberellin- and light-induced germination. Nature 258, 716–718 (1975)
Halmer, P., Bewley, J.D., Thorpe, T.A.: An enzyme to degrade lettuce endosperm cell walls. Appearance of a mannanase following phytochrome- and gibberellin-induced germination. Planta 130, 189–196 (1976)
Halmer, P., Bewley, J.D., Thorpe, T.A.:Degradation of the endosperm cell walls of Lactuca sativa L., cv. Grand Rapids. Timing of mobilisation of soluble sugars, lipid and phytate. Planta 139, 1–8 (1978)
Jacobs, S.: The determination of nitrogen in organic compounds by the indanetrione hydrate method. Analyst 85, 257–264 (1960)
Kawaguchi, K., Kashimura, N.: Preparation of p-nitrophenyl β-D-mannopyranoside by the Helferich method and separation of some anomeric p-nitrophenyl aldopyranoside acetates using thin layer chromatography. Agric. Biol. Chem. 40, 241–242 (1976)
Mandal, N.C., Burman, S., Biswas, B.B.: Isolation, purification and characterisation of phytase from germinating mung beans. Phytochemistry 11, 495–502 (1972)
Mayer, A.M.: The breakdown of phytin and phytase activity in germinating lettuce seeds. Enzymologia 19, 1–8 (1958)
Mayer, A.M., Krishmaro, M., Poljakoff-Mayber, A.: Isocitrate lyase and isocitrate dehydrogenase in germinating lettuce. Physiol. Plant. 21, 183–189 (1968)
Mayer, A.M., Poljakoff-Mayber, A.: The germination of seeds, 2nd Ed. Oxford: Pergamon Press 1975
Meyer, H., Mayer, A.M., Harel, E.: Acid phosphatases in germinating lettuce-evidence for partial activation. Physiol. Plant. 24, 95–101 (1971)
Mitchell, H.L.: Microdetermination of nitrogen in plant tissues. J. Assoc. Off. Anal. Chem. 55, 1–3 (1972)
Munro, H.N., Fleck, A.: Analysis of tissues and body fluids for nitrogenous constituents. In: Mammalian Protein Metabolism, vol. III, pp. 424–438, Munro, H.N., ed. New York: Academic Press 1969
Park, W.H., Chen, S.S.C.: Patterns of food utilisation by the germinating lettuce seeds. Plant Physiol. 53, 64–66 (1974)
Poljakoff-Mayber, A., Mayer, A.M.: Some quantitative changes in the fat metabolism of germinating lettuce seeds and their inhibition by coumarin. J. Exp. Bot. 6, 287–292 (1955)
Reid, J.S.G., Davies, C., Meier, H.: Endo-β-mannase, the leguminous aleurone layer and the storage galactomannan in germinating seeds of Trigonella foenum-graecum L. Planta 133, 219–222 (1977)
Reid, J.S.G., Meier, H.: Enzymic activities and galactomannan mobilisation in germinating seeds of fenugreek (Trigonella foenum-graecum L. Leguminosae). Secretion of α-galactosidase and β-mannosidase by the aleurone layer. Planta 112, 301–308 (1973)
Rimon, D.: Lipase activity of germinating lettuce seeds. Bull. Res. Counc. Isr., Sect. D 6, 53–55 (1957)
Simola, L.K., Sopanen, T.: Changes in the activity of certain enzymes of Acer pseudoplatanus L. cells at four stages of growth in suspension culture. Physiol. Plant. 23, 1212–1222 (1970)
Yemm, E.W., Cocking, E.C.: The determination of amino acids with ninhydrin. Analyst 80, 209–213 (1955)
Author information
Authors and Affiliations
Additional information
Part 2 of a series, of which the first was published in Planta 139, 1–8 (1978)
Rights and permissions
About this article
Cite this article
Leung, D.W.M., Reid, J.S.G. & Bewley, J.D. Degradation of the endosperm cell walls of Lactuca sativa L., cv. grand rapids in relation to the mobilisation of proteins and the production of hydrolytic enzymes in the axis, cotyledons and endosperm. Planta 146, 335–341 (1979). https://doi.org/10.1007/BF00387806
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00387806