Abstract
The timing of mobilisation of lipid, sucrose, raffinose and phytate in lettuce seeds (achenes) (cv. Grand Rapids) has been examined. These reserves (33%, 1.5%, 0.7%, 1.4% of achene dry weight, respectively) are stored mostly in the cotyledons. Except for a slight degradation of raffinose and increase in sucrose, there is no detectable reserve mobilisation during germination. The endosperm (8% of seed dry weight), which has thick, mannan-containing cell walls (carbohydrate, 3,4% of seed dry weight), is completely degraded within about 15h following germination. Mannanase activity increases about 100-fold during the same period and arises in all regions of the endosperm. Also during this period sucrose and raffinose are degraded and fructose and glucose accumulate in the embryo. The endosperm hydrolysis products are taken up by the embryo, and are probably used as an additional reserve to support early seedling growth. However, endosperm cell-wall carbohydrates, such as mannose, are not found as free sugars. Lipid and phytate are degraded in a later, second phase of mobilisation. Low levels of sucrose are present in the embryo, mostly in the cotyledons, and large amounts of fractose and glucose (14% of seedling dry weight at 3 days after sowing) accumulate in the hypocotyl and radicle. It is suggested that sucrose, produced in the cotyledons by gluco-neogenesis, is translocated to the axis and converted there to fructose and glucose.
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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 (in press)
Borthwick, H.A., Robbins, W.W.: Lettuce seed and its germination. Hilgardia (Berkeley) 3, 275–305 (1928)
Cherry, J.H.: Molecular biology of plants. A text manual. New York-London: Columbia University Press 1973
Eldan, M., Mayer, A.M.: Acid invertase in germinating Lactuca sativa: evidence for de novo synthesis. Phytochemistry 13, 389–395 (1976)
Eldan, M., Mayer, A.M., Poljakoff-Mayber, A., Eldan, M.: Difference in subcellular localisation of isocitrate lyase in lettuce seeds of different ages. Plant and Cell Physiol. 15, 169–173 (1974)
Evenari, M.: The physiological action and biochemical importance of germination inhibitors. Symp. Soc. Exp. Biol. 11, 21–43 (1957)
Fiske, C.M., Subbarow, Y.: The colorimetric determination of phosphorus. J. Biol. Chem. 66, 375–400 (1926)
Gambhir, I.R., Dutt, S.: Chemical examination of the seeds of Lactuca scariola (Linn.). Ind. Soap J. 12, 49–53 (1946)
Griffiths, A.E.: Observations on the germination of lettuce seeds. Contrib. Boyce Thompson Institute 9, 329–337 (1938)
Halmer, P., Bewley, J.D., Thorpe, T.A.: An enzyme to degrade the lettuce endosperm cell wall 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)
Horst, B.L.: Studies on the thermodormancy of lettuce seeds as effected by several growth regulators. Ph. D. thesis, Univ. of Calif., Riverside 1972
Jones, R.L.: The structure of the lettuce endosperm. Planta 121, 133–146 (1974)
McCleary, B.V., Matheson, N.K.: α-D-Galactosidase activity and galactomannan and galactosylsucrose oligosaccharide depletion in germinating legume seeds. Phytochemistry 13, 1747–1757 (1974)
Matheson, N.K., Strother, S.: The utilisation of phytate by germinating wheat. Phytochemistry 8, 1349–1356 (1969)
Mayer, A.M.: The breakdown of phytin and phytase activity in germinating lettuce seeds. Enzymologia 19, 1–8 (1958)
Mayer, A.M., Krishmaro, N., Poljakoff-Mayber, A.: Isocitric lyase and isocitric dehydrogenase in germinating lettuce. Physiol. Plant. 21, 183–189 (1968)
Mayer, A.M., Poljakoff-Mayber, A.: Biochemical events during the normal germination of lettuce. In: Physiology, ecology and biochemistry of germination, vol. A, pp. 483–487, Borris, H., ed. Greifswald: Ernst-Moritz-Arndt-Univ. 1967
Mayer, A.M., Poljakoff-Mayber, A.: The germination of seeds. 2nd ed. Oxford: Pergamon Press 1975
Nabors, M.W., Kugrens, P., Ross, C.: Photodormant lettuce seeds: phytochrome-induced protein and lipid degradation. Planta 117, 361–365 (1974)
Oshima, M., Taylor, T.G., Williams, A.: Variations in the concentration of phytic acid in the blood of the domestic fowl. Biochem. J. 92, 42–46 (1964)
Park, W.M., Chen, S.S.C.: Patterns of food utilization by the germinating lettuce seed. Plant Physiol. 53, 64–66 (1974)
Paulson, R.E., Srivastava, L.M.: The fine structure of the embryo of Lactuca sativa. I. Dry embryo. Can. J. Bot. 46, 1437–1445 (1968).
Poljakoff-Mayber, A.: Changes in the metabolism of lettuce seeds during germination and its inhibition. Palest. J. Bot. Jerusalem. 5, 180–185 (1952)
Poljakoff-Mayber, A.: Further identification of the sugars present in lettuce seeds. Bull. Res. Counc. Israel 3, 248 (1954)
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.: Reserve carbohydrate metabolism in germinating seeds of Trigonella foenum graecum L. (Leguminosae). Planta 100, 131–142 (1971)
Rimon, D.: Lipase activity of germinating lettuce seeds. Bull. Res. Counc. Israel 6D, 53–55 (1957)
Roberts, R.M., Cetorelli, J.J.: UDP-D-glucuronic acid pyrophosphorylase and the formation of UDP-D-glucuronic acid in plants. In: Biogenesis of plant cell wall polysaccharides, pp. 49–68, Loewus, F., ed. New York-London: Academic Press 1973
Srivastava, L.M., Paulson, R.E.: The fine structure of the embryo of Lactuca sativa. II. Changes during germination. Can. J. Bot. 46, 1447–1461 (1968)
Stuart, D.A., Jones, R.L.: Roles of extensibility and turgor in gibberellin- and dark-stimulated growth. Plant Physiol. 59, 61–68 (1977)
Sweeley, C.C., Bentley, R., Makita, M., Wells, W.W.: Gas-liquid chromatography of trimethylsilyl derivatives of sugars and related substances. J. Am. Chem. Soc. 85, 2497–2507 (1963)
Woodstock, L.W., Toole, V.K.: Respiration of Grand Rapids lettuce (Lactuca sativa L.) seeds in relation to chemical and photocontrol of germination. Plant Cell Physiol. 18, 1–8 (1977)
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Halmer, P., Bewley, J.D. & Thorpe, T.A. Degradation of the endosperm cell walls of Lactuca sativa L., cv. Grand Rapids. Planta 139, 1–8 (1978). https://doi.org/10.1007/BF00390802
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DOI: https://doi.org/10.1007/BF00390802