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Regulation of diacylglycerol acyltransferase in developing seeds of castor

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Lipids

Abstract

We have previously reported the cloning of castor diacylglycerol acyltransferase (RcDGAT) based on its homology to other plant type 1 diacylglycerol acyltransferases (DGATs). To elucidate the physiological role of the RcDGAT, we have investigated the regulation of RcDGAT expression in developing seeds of castor. The RcDGAT transcript appeared at 12 d after pollination (DAP), reached the highest level at 26 DAP, and declined rapidly after that. However, the RcDGAT protein started to accumulate at 26 DAP, reached its peak at 47 DAP, then remained at this high level until 54 DAP. The significant difference between the expression of mRNA and protein indicates that gene expression of RcDGAT in maturing castor seeds is controlled at the posttranscriptional level. We found that DGAT activity measured in microsomal membranes isolated from seed at different stages of development was parallel to RcDGAT protein level, suggesting DGAT activity is mainly a function of the level of RcDGAT protein. We monitored the triacylglycerol (TG) composition and content during seed development. Compared with the overall rate of TG accumulation, DGAT activity appeared coincidently with the onset of lipid accumulation at 26 DAP; the highest DGAT activity occurred during the rapid phase of lipid accumulation at 40 DAP; and a decline in DGAT activity coincided with a decline in the accumulation rate of TG after 40 DAP. The ricinoleate-containing TG content was very low (only about 7%) in oil extracted from seeds before 19 DAP; however it increased up to about 77% of the oil at 26 DAP. The relative amount of triricinolein in oil at 26 DAP was 53 times higher than that at 19 DAP, and it was about 76% of the amount present in oil from mature castor seeds. The close correlation between profiles of RcDGAT activity and oil accumulation confirms the role of RcDGAT in castor oil biosynthesis.

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Abbreviations

AG:

acylglycerols

DAP:

days after pollination

DG:

diacylglycerol

DGAT:

diacylglycerol acyltransferase

DIG:

digoxigenin

PDAT:

phospholipid: diacylglycerol transferase

RcDGAT:

castor DGAT

TG:

triacylglycerol

References

  1. Caupin, H.J. (1997) Products from Castor Oil: Past, Present, and Future, in Lipid Technologies and Applications (Gunstone, F.D., and Padley, F.B., eds.), pp. 787–795, Marcel Dekker, New York.

    Google Scholar 

  2. McKeon, T.A., and Lin, J.T. (2002) Biosynthesis of Ricinoleic Acid for Castor Oil Production, in Lipid Biotechnology (Kuo, T.M., and Gardner, H.W., eds), pp. 129–139, Marcel Dekker, New York.

    Google Scholar 

  3. Ohlrogge, J.B., and Jaworski, J.G. (1997) Regulation of Fatty Acid Synthesis, Annu. Rev. Plant Physiol. Plant Mol. Biol. 48, 109–136.

    Article  PubMed  CAS  Google Scholar 

  4. Ichihara, K., Takahashi, T., and Fujii, S. (1988) Diacylglycerol Acyltransferase in Maturing Safflower Seed: Its Influences on the Fatty Acid Composition and on the Rate of Triacylglycerol Synthesis, Biochem. Biophys. Acta 958, 125–129.

    PubMed  CAS  Google Scholar 

  5. Perry, H.J., and Harwood, J.L. (1993) Changes in the Lipid Content of Developing Seeds of Brassica napus, Phytochemistry 32, 1411–1415.

    Article  CAS  Google Scholar 

  6. Stymne, S., and Stobart, K. (1987) Triacylglycerol Biosynthesis, in The Biochemistry of Plants (Stumpf, P.K., and Conn, E.E., eds.), Vol. 9, 175–214, Academic Press, New York.

    Google Scholar 

  7. Hobbs, D.H., Lu, C.F., and Hill, M.J. (1999) Cloning of a cDNA Encoding Diacylglycerol Acyltransferase from Arabidopsis thaliana and Its Functional Expression, FEBS Lett. 452, 145–149.

    Article  PubMed  CAS  Google Scholar 

  8. Bouvier-Nave, P., Benveniste, P., Oelkers, P., Sturley, S.L., and Schaller, H. (2000) Expression in Yeast and Tobacco of Plant cDNAs Encoding Acyl CoA:Diacylglycerol Acyltransferase, Eur. J. Biochem. 267, 85–96.

    Article  PubMed  CAS  Google Scholar 

  9. Nykiforuk, C.L., Furukawa-Stoffer, T.L., Huff, P.W., Sarna, M., Laroche, A., Moloney, M.M., and Weselake, R.J. (2002) Characterization of cDNAs Encoding Diacylglycerol Acyltransferase from Cultures of Brassica napus and Sucrose-Mediated Induction of Enzyme Biosynthesis, Biochim. et Biophys. Acta 1580, 95–109.

    CAS  Google Scholar 

  10. Lardizabal, K.D., Mai, J.T., Wagner, N.W., Wyrick, A., Voelker, T., and Hawkins, D. (2001) DGAT2 Is a New Diacylglycerol Acyltransferase Gene Family, J. Biol. Chem. 276, 38862–38869.

    Article  PubMed  CAS  Google Scholar 

  11. He, X., Turner, C., Chen, G., Lin, J.-T., and McKeon, T.A. (2004) Cloning and Characterization of a cDNA Encoding Diacylglycerol Acyltransferase from Castor Bean, Lipids, 39, 311–318.

    PubMed  CAS  Google Scholar 

  12. Wiberg, E., Banas, A., and Stymne, S. (1997) Fatty Acid Distribution and Lipid Metabolism in Developing Seeds of Laurate-Producing Rape (Brassica napus L.), Planta 203, 342–348.

    Article  Google Scholar 

  13. Bao, X., and Ohlrogge, J.B. (1999) Supply of Fatty Acid Is One Limiting Factor in the Accumulation of Triacylglycerol in Developing Embryos, Plant Physiol. 120, 1057–1062.

    Article  PubMed  CAS  Google Scholar 

  14. O'Neill, C.M., Gill, S., Hobbs, D.H., Morgan, C., and Bancroft, I. (2003) Natural Variation for Seed Oil Composition in Arabidopsis thaliana, Phytochemistry 64, 1077–1090.

    Article  PubMed  Google Scholar 

  15. Gu, Y.Q., Yang, C., Thara, V.K., Zhou, J., and Martin, G.B. (2000) Pti4 Is Induced by Ethylene and Salicylic Acid, and Its Product Is Phosphorylated by the Pto Kinase, Plant Cell 12, 771–785.

    Article  PubMed  CAS  Google Scholar 

  16. Lu, C., Noyer, S.B., Hobbs, D.H., Kang, J., Wen, Y., Krachtus, D., and Hills, M. (2003) Expression Pattern of Diacylglycerol Acyltransferase-1, an Enzyme Involved in Triacylglycerol Biosynthesis, in Arabidopsis thaliana, Plant Mol. Biol. 52, 31–41.

    Article  PubMed  CAS  Google Scholar 

  17. Cases, S., Smith, S.J., Zheng, Y.W., Myers, H.M., Lear, S.R., Sande, E., Novak, S., Collins, C., Welch, C.B., Lusis, A.J., et al. (1998) Identification of a Gene Encoding an Acyl CoA:Diacylglycerol Acyltransferase, a Key Enzyme in Triacylglycerol Synthesis, Proc. Natl. Acad. Sci. USA 95, 13018–13023.

    Article  PubMed  CAS  Google Scholar 

  18. Lin, J.T., McKeon, T.A., Goodrich-Tanrikulu, M., and Stafford, A.E. (1996) Characterization of Oleoyl-12-hydroxylase in Castor Microsomes Using the Putative Substrate, 1-Acyl-2-oleoyl-sn-glycero-3-phosphocholine, Lipids 31, 571–577.

    Article  PubMed  CAS  Google Scholar 

  19. Lin, J.T., Woodruff, C.L., and McKeon, T.A. (1997) Non-aqueous Reversed-Phase High-Performance Liquid Chromatography of Synthetic Triacylglycerols and Diacylglycerols, J. Chromatogr. A 782, 41–48.

    Article  CAS  Google Scholar 

  20. Smith, M.A., Moon, H., Chowrira, G., and Kunst, L. (2003) Heterologous Expression of a Fatty Acid Hydroxylase Gene in Developing Seeds of Arabidopsis thaliana, Planta 217, 507–516.

    Article  PubMed  CAS  Google Scholar 

  21. Lin, J.T., Lew, K.M., Chen, J.M., Iwasaki, Y., and McKeon, T.A. (2000) Metabolism of 1-Acyl-2-oleoyl-sn-glycero-3-phosphoethanolamine in Castor Oil Biosynthesis, Lipids 35, 481–486.

    Article  PubMed  CAS  Google Scholar 

  22. Lin, J.T., Turner, C., Liao, L.P., and McKeon, T.A. (2003) Identification and Quantification of the Molecular Species of Acylglycerols in Castor Oil by HPLC Using ELSD, J. Liq. Chromatogr. Rel. Tech. 26, 773–780.

    Article  CAS  Google Scholar 

  23. Weselake, R.J., Taylor, D.C., Pomeroy, M.K., Lawson, S.L., and Underhill, E.W. (1991) Properties of Diacylglycerol Acyltransferase from Microspore-Derived Embryos of Brassica napus, Phytochemistry 30, 3533–3538.

    Article  CAS  Google Scholar 

  24. Ichihara, K., Takahashi, T., and Fujii, S. (1988) Diacylglycerol Acyltransferase in Maturing Safflower Seeds: Its Influences on the Fatty Acid Composition of Triacylglycerol and on the Rate of Triacylglycerol Synthesis, Biochim. Biophys. Acta. 958, 125–129.

    PubMed  CAS  Google Scholar 

  25. Bernerth, R., and Frentzen, M. (1990) Utilization of Erucoyl-CoA by Acyltransferases from Developing Seeds of Brassica napus (L.) Involved in Triacylglycerol Biosynthesis, Plant Sci. 67, 21–28.

    Article  CAS  Google Scholar 

  26. Yu, Y., Zhang, Y., Oelkers, P., Sturley, S.L., Rader, D.J., and Ginsberg, H.N. (2002) Posttranscriptional Control of the Expression and Function of Diacylglycerol Acyltransferase-1 in Mouse Adipocytes, J. Biol. Chem. 277, 50876–50884.

    Article  PubMed  CAS  Google Scholar 

  27. Cases, S., Stone, S.J., Zhou, P., Yen, E., Tow, B., Lardizabal, K.D., Voelker, T., and Farese, R.V., Jr. (2001) Cloning of DGAT2, a Second Mammalian Diacylglycerol Acyltransferase, and Related Family Members, J. Biol. Chem. 276, 38870–38876.

    Article  PubMed  CAS  Google Scholar 

  28. Tzen, J.T.C., Cao, Y.Z., Laurent, P., Ratnayake, C., and Huang, A.H.C. (1993) Lipids, Proteins, and Structure of Seed Oil Bodies from Diverse Species, Plant Physiol. 101, 267–276.

    PubMed  CAS  Google Scholar 

  29. Weselake, R.J., Pomeroy, M.K., Furukawa, T.L., Golden, J.L., Little, D.B., and Laroche, A. (1993) Developmental Profile of Diacylglycerol Acyltransferase in Maturing Seeds of Oilseed Rape and Safflower and Microspore-Derived Cultures of Oilseed Rape, Plant Physiol. 102, 565–571.

    PubMed  CAS  Google Scholar 

  30. Dahlqvist, A., Stahl, U., Lenman, M., Banas, A., Lee, M., Sandager, L., Ronne, H., and Stymne, S. (2000) Phospholipid: Diacylglycerol Acyltransferase: An Enzyme That Catalyzes the Acyl-CoA-Independent Formation of Triacylglycerol in Yeast and Plants, Proc. Natl. Acad. Sci. USA 97, 6487–6492.

    Article  PubMed  CAS  Google Scholar 

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Authors and Affiliations

  1. Western Regional Research Center, USDA, 800 Buchanan St., 94710, Albany, California, USA

    Xiaohua He, Grace Q. Chen, Jiann-Tsyh Lin & Thomas A. McKeon

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  1. Xiaohua He
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  2. Grace Q. Chen
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  3. Jiann-Tsyh Lin
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  4. Thomas A. McKeon
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Correspondence to Thomas A. McKeon.

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He, X., Chen, G.Q., Lin, JT. et al. Regulation of diacylglycerol acyltransferase in developing seeds of castor. Lipids 39, 865–871 (2004). https://doi.org/10.1007/s11745-004-1308-1

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  • DOI: https://doi.org/10.1007/s11745-004-1308-1

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