Abstract
Plant oil is an important renewable resource for biodiesel production and for dietary consumption by humans and livestock. Through genetic mapping of the oil trait in plants, studies have reported multiple quantitative trait loci (QTLs) with small effects, but the molecular basis of oil QTLs remains largely unknown1,2,3,4,5. Here we show that a high-oil QTL (qHO6) affecting maize seed oil and oleic-acid contents encodes an acyl-CoA:diacylglycerol acyltransferase (DGAT1-2), which catalyzes the final step of oil synthesis. We further show that a phenylalanine insertion in DGAT1-2 at position 469 (F469) is responsible for the increased oil and oleic-acid contents. The DGAT1-2 allele with F469 is ancestral, whereas the allele without F469 is a more recent mutant selected by domestication or breeding. Ectopic expression of the high-oil DGAT1-2 allele increases oil and oleic-acid contents by up to 41% and 107%, respectively. This work provides insights into the molecular basis of natural variation of oil and oleic-acid contents in plants and highlights DGAT as a promising target for increasing oil and oleic-acid contents in other crops.
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References
Berke, T.G. & Rocheford, T.R. Quantitative trait loci for flowering, plant and ear height and kernel traits in maize. Crop Sci. 35, 1542–1549 (1995).
Song, X.-F., Song, T.-M., Dai, J.-R. & Rocheford, T.R. QTL mapping of kernel oil concentration with high-oil maize by SSR markers. Maydica 49, 41–48 (2004).
Mangolin, C.A. et al. Mapping QTLs for kernel oil content in a tropical maize population. Euphytica 137, 251–259 (2004).
Laurie, C.C. et al. The genetic architecture of response to long-term artificial selection for oil concentration in the maize kernel. Genetics 168, 2141–2155 (2004).
Clark, D., Dudley, J.W., Rocheford, T.R. & LeDeaux, J.R. Genetic analysis of corn kernel chemical composition in the random mated 10 generation of the cross of generations 70 of IHO × ILO. Crop Sci. 46, 807–819 (2006).
White, P.J. & Weber, E.J. in Corn: Chemistry and Technology 2nd edn, Vol. 10 (eds. White, P.J. & Johnson, L.A.) Lipids of the kernel, 355–395 (American Association of Cereal Chemists, Inc., St. Paul, Minnesota, 2003).
Kinney, A.J., Cahoon, E.B. & Hitz, W.D. Manipulating desaturase activities in transgenic crop plants. Biochem. Soc. Trans. 30, 1099–1103 (2002).
Moose, S.P., Dudley, J.W. & Rocheford, T.R. Maize selection passes the century mark: a unique resource for twenty-first century genomics. Trends Plant Sci. 9, 358–364 (2004).
Lambert, R.J., Alexander, D.E. & Mejaya, I.J. in Plant Breeding Reviews Part 1, Vol. 24 (ed. Janick, J.) Single kernel selection for increased grain oil in maize synthetics and high-oil hybrid development, 153–175 (John Wiley & Sons, Inc., Hoboken, New Jersey, 2004).
Poneleit, C.G. & Alexander, D.E. Inheritance of linoleic and oleic acids in maize. Science 147, 1585–1586 (1965).
Alrefai, R., Berke, T.G. & Rocheford, T.R. Quantitative trait locus analysis of fatty acid concentrations in maize. Genome 38, 894–901 (1995).
Jako, C. et al. Seed-specific over-expression of an Arabidopsis cDNA encoding a diacylglycerol acyltransferase enhances seed oil content and seed weight. Plant Physiol. 126, 861–874 (2001).
Lung, S.-C. & Weselake, R.J. Diacylglycerol acyltransferase: a key mediator of plant triacylglycerol synthesis. Lipids 41, 1073–1088 (2006).
Grisart, B. et al. Genetic and functional confirmation of the causality of the DGAT1 K232A quantitative trait nucleotide in affecting milk yield and composition. Proc. Natl. Acad. Sci. USA 101, 2398–2403 (2004).
Krogh, A., Larsson, B., von Heijne, G. & Sonnhammer, E.L.L. Predicting transmembrane protein topology with a hidden Markov model: application to complete genomes. J. Mol. Biol. 305, 567–580 (2001).
Ohlrogge, J. & Browse, J. Lipid biosynthesis. Plant Cell 7, 957–970 (1995).
Voelker, T. & Kinney, A.J. Variations in the biosynthesis of seed-storage lipids. Annu. Rev. Plant Physiol. Plant Mol. Biol. 52, 335–361 (2001).
Beló, A. et al. Whole genome scan detects an allelic variant of fad2 associated with increased oleic acid levels in maize. Mol. Genet. Genomics 279, 1–10 (2008).
Shen, B., Sinkevicius, K.W., Selinger, D.A. & Tarczynski, M.C. The homeobox gene GLABRA2 affects seed oil content in Arabidopsis. Plant Mol. Biol. 60, 377–387 (2006).
Ishida, Y. et al. High efficiency transformation of maize (Zea mays L.) mediated by Agrobacterium tumefaciens. Nat. Biotechnol. 14, 745–750 (1996).
Christensen, A.H., Sharrock, R.A. & Quail, P.H. Maize polyubiquitin genes: structure, thermal perturbation of expression and transcript splicing, and promoter activity following transfer to protoplasts by electroporation. Plant Mol. Biol. 18, 675–689 (1992).
An, G. et al. Functional analysis of the 3′ control region of the potato wound-inducible proteinase inhibitor II gene. Plant Cell 1, 115–122 (1989).
Zhao, Z.Y. & Ranch, J. Transformation of maize via Agrobacterium tumefaciens using a binary co-integrate vector system. Methods Mol. Biol. 318, 315–323 (2006).
Milcamps, A. et al. Isolation of a gene encoding a 1,2-diacylglycerol-sn-acetyl-CoA acetyltransferase from developing seeds of Euonymus alatus. J. Biol. Chem. 280, 5370–5377 (2005).
Hara, A. & Radin, N.S. Lipid extraction of tissues with a low-toxicity solvent. Anal. Biochem. 90, 420–426 (1978).
Acknowledgements
We thank B. Li for providing the maize physical map and advice on map-based cloning, S. Zhen for growing corn plants in the greenhouse, C. Li for laboratory support, J. Hazebroek for fatty acid composition analysis, H. Sullivan for SNP marker development, the Pioneer molecular marker laboratory for genotyping, T. Colbert for valuable discussion and D. Selinger and M. Ayele for bioinformatics support. We are grateful to B. Hitz for his support and R. Jung for critical review of the manuscript.
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B.S. and M.C.T. conceived and directed the project; M.E.W., G.Y.Z., P.Z. and J.L. conducted oil QTL mapping; P.Z. conducted fine mapping and cloning; W.B.A. performed the oil analysis; K.R. and S.Z. performed DGAT activity assay and immunoblot; K.G. conducted vector construction; J.R. conducted corn transformation; D.N. and W.S. conducted field experiments; D.B. completed genotyping; V.L. and S.D. conducted BAC sequencing and DGAT resequencing; B.S., P.Z., K.R. and M.C.T. analyzed the data and wrote the manuscript.
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Zheng, P., Allen, W., Roesler, K. et al. A phenylalanine in DGAT is a key determinant of oil content and composition in maize. Nat Genet 40, 367–372 (2008). https://doi.org/10.1038/ng.85
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DOI: https://doi.org/10.1038/ng.85
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