Summary
The synthesis and deposition of the epicuticular waxes in barley are determined by the eceriferum (cer) loci. On the uppermost internodes, leaf sheaths and spikes of the wild type Bonus, the β-diketones and hydroxy-β-diketones (almost entirely hentriacontan-14,16-dione and 25-hydroxyhentriacontan-14,16-dione, respectively) are the predominating wax classes. In these same waxes esters containing alkan-2-ols (primarily tridecan-2-ol and pentadecan-2-ol) are present. Analyses of the β-diketone content and ester composition of waxes from Bonus and eight cer mutants led to the hypothesis that these two wax classes are synthesized from common precursors, namely C14 and C16 chain elongation intermediates. Subsequently, decarboxylation with a simultaneous retention of the carbonyl groups in the β-position would lead to the esterified alkan-2-ols while retention of two carbonyl groups plus further elongation would lead to the β-diketones. This closer biosynthetic relationship of the β-diketones to the esterified alkan-2-ols than to the other lipid classes-hydrocarbons, alkan-1-ol containing esters, aldehydes, alkan-1-ols and free acids—found in all barley waxes is illustrated schematically and the approximate sites of action of the cer loci indicated.
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Dierickx, P.J., Buffel, K.: Hydroxy-hentriacontanediones from Avena sativa. Phytochem. 11, 2654–2655 (1972)
Horn, D.H.S., Kranz, Z.H., Lamberton, J.A.: The composition of Eucalyptus and some other leaf waxes. Aust. J. Chem. 17, 464–476 (1964)
Jackson, L.L.: Beta-diketone, alcohol and hydrocarbons of barley surface lipids. Phytochem. 10, 487–490 (1971)
Jacobson, B.S., Kannangara, C.G., Stumpf, P.K.: Biosynthesis of α-linolenic acid by disrupted spinach chloroplasts. Biochem. biophys. Res. Commun. 51, 487–493 (1973a)
Jacobson, B.S., Kannangara, C.G., Stumpf, P.K.: The elongation of medium chain trienoic acids to α-linolenic acid by a spinach chloroplast stroma system. Biochem. biophys. Res. Commun. 52, 1190–1198 (1973b)
Kannangara, C.G., Jacobson, B.S., Stumpf, P.K.: In vivo biosynthesis of α-linolenic acid in plants. Biochem. biophys. Res. Commun. 52, 648–655 (1973)
Khan, A.A., Kolattukudy, P.E.: Decarboxylation of long chain fatty acids to alkanes by cell free preparations of pea leaves (Pisum sativum). Biochem. biophys. Res. Commun. 61, 1379–1386 (1974)
Kolattukudy, P.E.: Mechanisms of synthesis of waxy esters in broccoli (Brassica oleracea). Biochemistry (Wash.) 6, 2705–2717 (1967)
Kolattukudy, P.E.: Plant waxes. Lipids 5, 259–275 (1970)
Kolattukudy, P.E., Buckner, J.S.: Chain elongation of fatty acids by cell-free extracts of epidermis from pea leaves (Pisum sativum). Biochem. biophys. Res. Commun. 46, 801–807 (1972)
Kolattukudy, P.E., Buckner, J.S., Liu, T.J.: Biosynthesis of secondary alcohols and ketones from alkanes. Arch. Biochem. Biophys. 156, 613–620 (1973)
Kolattukudy, P.E., Liu, T.J.: Direct evidence for biosynthetic relationships among hydrocarbons, secondary alcohols and ketones in Brassica oleracea. Biochem. biophys. Res. Commun. 41, 1369–1374 (1970)
Kolattukudy, P.E., Walton, T.J.: The biochemistry of plant cuticular lipids. Prog. Chem. Fats Other Lipids 13, 119–175 (1972)
Lundqvist, U., Wettstein, D. von: Induction of eceriferum mutants in barley by ionizing radiations and chemical mutagens. Hereditas (Lund) 48, 342–362 (1962)
Lundqvist, U., Wettstein, D. von: Stock list for the eceriferum mutants II. Barley Genetics Newsletter 3, 110–112 (1973)
Lundqvist, U., Wettstein, D. von: Stock list for the eceriferum mutants III. Barley Genetics Newsletter 5, 88–90 (1975)
Lundqvist, U., Wettstein-Knowles, P. von, Wettstein, D. von: Induction of eceriferum mutants in barley by ionizing radiations and chemical mutagens. II. Hereditas (Lund) 59, 473–504 (1968)
Martin, J.T., Juniper, B.E.: The cuticles of plants. Edinburgh: Edward Arnold Publishers Ltd. 1970
Netting, A.G., Wettstein-Knowles, P. von: Biosynthesis of the β-diketones of barley spike epicuticular wax. Arch. Biochem. Biophys. in press (1975)
Streibl, M., Koncčný, K., Trka, A., Ubik, K., Pazlar, M.: Composition of the wax of rye straw. Collection Czechoslov. Chem. Commun. 39, 475–479 (1974)
Søgaard, A.B.: Continued linkage studies on eceriferum mutants in barley. Barley Genetics Newsletter 3, 57–61 (1973)
Trka, A., Streibl, M.: Mass spectra of long-chain aliphatic β-diketones and some of their derivatives. Collection Czechoslov. Chem. Commun. 39, 468–474 (1974)
Tulloch, A.P., Hoffman, L.L.: Leaf wax of durum wheat. Phytochem. 10, 871–876 (1971)
Tulloch, A.P., Hoffman, L.L.: Leaf wax of oats. Lipids 8, 617–622 (1973a)
Tulloch, A.P., Hoffman, L.L.: Leaf wax of Triticum aestivum. Phytochem. 12, 2217–2223 (1973b)
Tulloch, A.P., Weenink, R.O.: Composition of the leaf wax of Little Club wheat. Canad. J. Chem. 47, 3119–3126 (1969)
Wettstein-Knowles, P. von: The molecular phenotypes of the eceriferum mutants. In: Barley genetics. II. Proc. 2nd Intern Barley Genet. Symp. (1969), p. 146–193, Nilan, R.A. ed., Pullman, Wash., USA: Washington State Univ. Press 1971
Wettstein-Knowles, P. von: Genetic control of β-diketone and hydroxy-β-diketone synthesis in epicuticular waxes of barley. Planta (Berl.) 106, 113–130 (1972)
Wettstein-Knowles, P. von: Ultrastructure and origin of epicuticular wax tubes. J. Ultrastruct. Res. 46, 483–498 (1974a)
Wettstein-Knowles, P. von: Gene mutation in barley inhibiting the production and use of C26 chains in epicuticular wax formation. FEBS Letters 42, 187–191 (1974b)
Wettstein-Knowles, P. von, Netting, A.G.: Esterified alkan-1-ols and alkan-2-ols in barley epicuticular wax. Lipids submitted (1976)
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Communicated by G. Melchers
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von Wettstein-Knowles, P. Biosynthetic relationships between β-diketones and esterified alkan-2-ols deduced from epicuticular wax of barley mutants. Molec. Gen. Genet. 144, 43–48 (1976). https://doi.org/10.1007/BF00277302
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DOI: https://doi.org/10.1007/BF00277302