Abstract
An efficient method to determine the fatty acid composition of a large number of small seed tissue samples is needed to facilitate the genetic manipulation of seed lipid composition in soybean and other oilseeds. A rapid procedure has been developed to simultaneously extract and transmethylate the neutral lipids from soybean cotyledons at 90°C in a mixture of hexane and 1% H2SO4 in methanol (pretreatment of cotyledon pieces with hexane prior to methanolysis was found to improve yields). Fatty acid methyl esters were analyzed by capillary or packed column gas chromatography. The method required less than 10 mg of cotyledon tissue which could be taken from opposite the embryo axis so the sampled seed remained viable.
This direct transmethylation method was compared to Soxhlet extraction and subsequent acid methanolysis and to methods requiring separate steps for extraction [with hexane alone, hexane:isopropanol (3:2) or chloroform:methanol (2:1)], washing, solvent removal and methanolysis. Determinations of fatty acid content and composition were similar among the four methods. Approximately 30 times more samples could be analyzed (more than 2000 samples per month) using the direct transesterification method than were possible with the Soxhlet procedure. This direct transmethylation method is more rapid, requires less tissue, and provides results comparable to other inexpensive methods. It should be especially useful in breeding studies where large numbers of small samples are encountered.
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References
Smith, K.J.,J. Am. Oil Chem. Soc. 58:135 (1981).
Smouse, T.H.,Ibid. 56:747A (1979).
Burton, J.W., R.F. Wilson and C.A. Brim,Crop Sci. 23:744 (1983).
Hammond, E.G., and W.R. Fehr,JAOCS 61:1713 (1984).
Miller, J.F., D.C. Zimmerman and B.A. Vick,Crop Sci. 27:923 (1987).
Wilcox, J.R., J.F. Cavins and N.C. Nielsen,J. Am. Oil Chem. Soc. 61:97 (1984).
Wilson, R.F., J.W. Burton and C.A. Brim,Crop Sci. 21:788 (1981).
Green, A.S.,Theor. Appl. Genet. 72:654 (1986).
Bligh, E.G., and W.J. Dyer,Can. J. Biochem. Physiol. 37:911 (1959).
Metcalfe, L.D., and A.A. Schmitz,Anal. Chem. 33:363 (1961).
Radin, N.S.,Meth. Enzymol. 14:245 (1969).
Chaven, C., T. Hymowitz and C.A. Newell,J. Am. Oil Chem. Soc. 59:23 (1982).
Browse, J., P.J. McCourt and C.R. Somerville,Anal. Biochem. 152:141 (1986).
Lepage, G., and C.C. Roy,J. Lipid Res. 27:114 (1986).
AOAC Official Methods of Analysis, 12th edn., Association of Official Analytical Chemists, Washington DC, 1975, Methods 14.080 and 14.081.
Overhults, D.G.,Drying Rate and Oil Quality of Soybeans as Related to Harvest and Drying Conditions, Masters’ Thesis, University of Kentucky, 1975.
Folch, J., M. Lees and G.H. Sloane-Stanley,J. Biol. Chem. 226:497 (1957).
Radin, N.S.,Meth. Enzymol. 72:5 (1981).
Wang, X.M., D.F. Hildebrand, H.D. Norman, M.L. Dahmer, J.B. St. John and G.B. Collins,Phytochemistry 26:955 (1987).
SAS User’s Guide: Statistics, Version 5 edn., SAS Institute Inc., Cary, NC, 1985.
Patton, G.M., S. Cann, H. Brunengraber and J.M. Lowenstein, Ibid.:8 (1981).
Wiese, K.L., and H.E. Snyder,J. Am Oil Chem. Soc. 64:402 (1987).
Freedman, B., R.O. Butterfield and E.H. Pryde, Ibid.:1375 (1986).
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Dahmer, M.L., Fleming, P.D., Collins, G.B. et al. A rapid screening technique for determining the lipid composition of soybean seeds. JAOCS 66, 543–548 (1989). https://doi.org/10.1007/BF02885445
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DOI: https://doi.org/10.1007/BF02885445