Abstract
Changes in fatty-acid metabolism were studied in soybean (Glycine max Merr.) cotyledons during senescence as well as in cotyledons which had been caused to regreen by removal of the epicotyl from the seedling. The activities of the enzymes acetyl-CoA synthetase (EC 6.2.1.1) and fatty-acid synthetase in plastids isolated from the cotyledons decreased during senescence but increased in response to regreening. These changes in enzyme activities followed the same pattern as changes in the quantities of chlorophyll and polyunsaturated fatty acids in this tissue. The in-vivo incorporation of [14C]acetate into total fatty acids in the senescing and regreening cotyledons did not vary markedly with age. In addition, the quantity of label in fatty acids did not decrease for as much as 60 h after the removal of the substrate. During this 60-h period however, there was substantial redistribution of the label among the individual fatty acids. While the labelling pattern of the individual fatty acids did not vary significantly with respect to age in the senescing cotyledons, there was a substantial increase in the synthesis of labelled polyunsaturated fatty acids in the regreening tissue. Thus, the incorporation of [14C]acetate into fatty acids did not reflect the changes in the quantities of the individual fatty acids in senescing tissue as well as they did in regreening tissue.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Appleqvist, L.-A.: Biochemical and structural aspects of storage and membrane lipids in developing oil-seeds. In: Recent advances in the chemistry and biochemistry of plant lipids, pp. 247–286, Galliard, T., Mercer, E.I., eds. London, New York: Academic Press 1975
Arditti, J., Dunn, A.: Experimental Plant Physiology. New York: Holt, Rinehart, Winston 1969
Arnon, D.I.: Copper enzymes in isolated chloroplasts. Polyphenoloxidase in Beta vulgaris. Plant Physiol. 24, 1–15 (1949)
Batt, T., Woolhouse, H.W.: Changing activities during senescence and sites of synthesis of photosynthetic enzymes in leaves of the Labiate, Perilla fructescens (L.). J. Exp. Bot. 26, 569–579 (1975)
Bligh, E.J., Dyer, W.J.: A rapid method of total lipid extraction and purification. Can. J. Biochem. Physiol. 37, 911–917 (1959)
Brooks, J.L., Stumpf, P.K.: Fat metabolism in higher plants. XXIX. Properties of a soluble fatty acid synthesizing system from lettuce chloroplasts. Arch. Biochem. Biophys. 106, 108–116 (1966)
Burton, D., Stumpf, P.K.: Control of plant acetyl-CoA carboxylase activity. Arch. Biochem. Biophys. 117, 604–614 (1966)
Dalgarn, D., Miller, P., Bricker, T., Speer, N., Jaworski, J.G., Newmann, D.W.: Galactosyl transferase activity of chloroplast envelopes from senescent soybean cotyledons. Plant Sci. Lett. 14, 1–6 (1979)
Dodge, J.D.: Changes in chloroplast fine structure during the autumnal senescence of Betula leaves. Ann. Bot. 34, 817–824 (1970)
Draper, S.R.: Lipid changes in senescing cucumber cotyledons. Phytochemistry 8, 1641–1647 (1969)
Glass, R.L.: Alcoholysis, saponification and the preparation of fatty acid methyl esters. Lipids 6, 919–925 (1971)
Harwood, J.L.: Fatty acid biosynthesis. In: Recent advances in the chemistry and biochemistry of plant lipids, pp 43–93, Galliard, T., Mercer, E.I., eds. London, New York: Academic Press (1975b)
Harwood, J.L., Stumpf, P.K.: Fatty acid biosynthesis by subcellular fractions of higher plants. Lipids 7, 8–19 (1972)
Huang, K.P.: A sensitive assay method for acetyl-CoA synthetase. Anal. Biochem. 37, 98–104 (1970)
Huang, K.P., Stumpf, P.K.: Fat metabolism in higher plants: LXI. Properties of potato acetyl coenzyme A synthetase. Arch. Biochem. Biophys. 140, 158–170 (1970)
Huber, D.J., Newman, D.W.: Relationship between lipid changes and plastid ultrastructural changes in senescing and regreening soybean cotyledons. J. Exp. Bot. 27, 490–511 (1976)
Kannangara, C.G., Jacobson, B.S., Stumpf, P.K.: A comparison of fatty acid synthesizing enzymes in chloroplasts isolated from mature and immature leaves of spinach. Plant Physiol. 52, 156–161 (1973)
Kannangara, C.G., Stumpf, P.K.: Fat metabolism in higher plants. LIV. A procaryotic type acetyl CoA carboxylase in spinach chloroplasts. Arch. Biochem. Biophys. 152, 83–91 (1972)
Krul, W.R.: Nucleic acid and protein metabolism of senescing and regrenerating soybean cotyledons. Plant Physiol. 54, 36–40 (1974)
Lowry, O.H., Rosebrough, N.J., Farr, A.L., Randall, R.J.: Protein measurement with the Folin phenol reagent. J. Biol. Chem. 193, 265–275 (1951)
Miflin, B.J., Beevers, H.: Isolation of intact plastids from a range of plant tissues. Plant Physiol. 53, 870–874 (1974)
Morrison, W.R., Smith, L.M.: Preparation of fatty acid methyl ester and dimethylacetals from lipids with boron fluoridemethanol. J. Lipid Res. 5, 600–608 (1964)
Porra, R.J., Stumpf, P.K.: Lipid biosynthesis in developing and germinating soybean cotyledons. Arch. Biochem. Biophys. 176, 53–62 (1976)
Roughan, P.G., Slack, C.R.: Long-chain acyl coenzyme A synthetase activity of spinach chloroplasts is concentrated in the envelope. Biochem. J. 162, 457–459 (1977)
Rutkoski, A., Jaworski, J.G.: Fatty acid synthetase from chloroplasts of soybean cotyledons: ACP activation and CoA inhibition. Biochem. Biophys. Res. Commun. 84, 428–434 (1978a)
Rutkoski, A., Jaworski, J.G.: An improved synthesis of malonylcoenzyme A. Anal. Biochem. 91, 370–373 (1978b)
Simon, E.J., Shemin, D.: The preparation of S-succinylcoenzyme A. J. Am. Chem. Soc. 75, 2520 (1953)
Stumpf, P.K.: Lipid biosynthesis in higher plants. In: Int. Rev. Biochem. 14, 215–237 (1977)
Wetterau, J.R., Newman, D.W., Jaworski, J.G.: Quantitative changes of fatty acids in soybean cotyledons during senescence and regreening. Phytochemistry 17, 1265–1268 (1978)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Place, M.A., Morgan, M.S., Rutkoski, A. et al. Fatty-acid metabolism in senescing and regreening soybean cotyledons. Planta 147, 246–250 (1979). https://doi.org/10.1007/BF00388746
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00388746