Abstract
Changes in total nitrogen, soluble amino nitrogen, lipid and phytate contents, and in the activities of proteinase (pH 7.0), isocitrate lyase and phytase were followed in the endosperm, cotyledons, and axis during germination of fenugreek seeds and subsequent growth of the seedlings. The endosperm is comprised largely of cell-wall galactomannans: the majority of the seed total nitrogen, lipid and phytate (5%, 8%, 0.44% of seed dry weight respectively) is localised within the cotyledons as stored reserves. Germination is completed after 10–14 h from the start of imbibition, but the major reserves are not mobilised during the first 24 h. Then the total nitrogen content of the cotyledons starts to decrease and that of the axis increases; there is a concomitant accumulation of soluble amino nitrogen in both cotyledons and axis. An increase in proteinase activity in the cotyledons correlates well with the depletion of total nitrogen therein. Depletion of lipid and phytate reserves in the different seed tissues constitutes a late event, occurring after 50 h from the start of imbibition, and is coincident with the final disintegration of the endosperm tissue. The depletion of phytate and stored lipids is accompanied by an increase in phytase and isocitrate lyase activity. It appears that the products of lipid hydrolysis are converted by gluconeogenesis to serve as the major source of sugars for the growing axis after the endosperm galactomannan has been completely mobilised.
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References
Dey, P.M. (1978) Biochemistry of plant galactomannas. Adv. Carbohydr. Chem. Biochem. 35, 341–376
Dixon, G.H., Kornberg, H.L. (1959) Assay methods for key enzymes of the glyoxylate cycle. Biochem. J. 72, 3 P
Gomori, G. (1955) Preparation of buffers for use in enzyme studies. Methods Enzymol. 1, 138–146
Halmer, P., Bewley, J.D., Thorpe, T.A. (1978) 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
Jacobs, S. (1960) The determination of nitrogen in organic compounds by the indanetrione hydrate method. Analyst 85, 257–264
Jacobsen, J.V., Varner, J.E. (1967) Gibberellic acid-induced synthesis of protease by isolated aleurone layers of barley. Plant Physiol 42, 1596–1600
Leung, D.W.M., Reid, J.S.G., Bewley, J.D. (1979) 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
Lowry, O.H., Lopez, J.A. (1946) The determination of inorganic phosphate in the presence of labile phosphate esters. J. Biol. Chem. 162, 421–428
McCleary, B.V., Matheson, N.K. (1974) α-D-Galactosidase activity and galactomannan and galactosylsucrose oligosaccharide depletion in germinating legume seeds. Phytochemistry 13, 1747–1757
McCleary, B.V., Matheson, N.K. (1974) α-D-Galactosidase activity and β-mannanase and β-mannosidase activity in germinating legume seeds. Phytochemistry 14, 1187–1194
McClendon, J.H., Nolan, W.G., Wenzler, H.F. (1976) The role of the endosperm in the germination of legumes: Galactomannan, nitrogen, and phosphorus changes in the germination of guar (Cyamopsis tetragonoloba; Leguminosae). Am. J. Bot. 63, 790–797
Mitchell, H.L. (1972) Microdetermination of nitrogen in plant tissues. J. Assoc. Off. Anal. Chem. 55, 1–3
Munro, H.N., Fleck, A. (1969) Analysis of tissues and body fluids for nitrogenous constituents. In: Mammalian protein metabolism, vol. III, pp. 424–438, Munro, H.N. ed., Academic Press, New York
Reid, J.S.G. (1971) Reserve carbohydrate metabolism in germinating seeds of Trigonella foenum-graecum L. (Leguminosae). Planta 100, 131–142
Reid, J.S.G., Bewley, J.D. (1979) A dual role for the endosperm and its galactomannan reserves in the germinative physiology of fenugreek (Trigonella foenum-graecum L.), an endospermic leguminous seed. Planta 147, 145–150
Reid, J.S.G., Davies, C., Meier, H. (1977) Endo-β-mannanase, the leguminous aleurone layer and the storage galactomannan in germinating seeds of Trigonella foenum-graecum L. Planta 133, 219–222
Reid, J.S.G., Meier, H. (1972) The function of the aleurone layer during galactomannan mobilisation in germinating seeds of fenugreek (Trigonella foenum-graecum L.), crimson clover (Trifolium incarnatum L.) and lucerne (Medicago sativa L.): a correlative biochemical and ultrastructural study. Planta 106, 44–60
Reid, J.S.G., Meier, H. (1973) 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, 301–303
Seiler, A. (1977) Galactomannabbau in keimenden Johannisbrodsamen (Ceratonia siliqua L.). Planta 134, 209–221
Yemm, E.W., Cocking, E.C. (1955) The determination of amino acids with ninhydrin. Analyst 80, 209–213
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Leung, D.W.M., Bewley, J.D. & Reid, J.S.G. Mobilisation of the major stored reserves in the embryo of fenugreek (Trigonella foenum-graecum L., Leguminosae), and correlated enzyme activities. Planta 153, 95–100 (1981). https://doi.org/10.1007/BF00384089
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DOI: https://doi.org/10.1007/BF00384089