Research Interests
My lab conducts basic and applied research on plant lipid metabolism. The goals of our research are to enhance the nutritional and industrial value of crop plants and to probe the synthesis and function of bioactive lipids for nutritional biofortification and improved agronomic performance of crops.
Oilseed crops such as soybean can serve as platforms for the sustainable production of fatty acids for human and livestock nutrition, bio-based fuels, and industrial chemicals. Functional genomic studies in my lab are aimed understanding the synthesis and metabolism of high-value fatty acids, such as the conjugated fatty acid eleostearic acid. We are attempting to identify genes from non-agronomic species that can be used to generate novel vegetable oils in soybean and the emerging oilseed camelina. My lab also is actively involved in understanding the regulation of flux in the plastid isoprenoid pathway in order to enhance the content of vitamin E antioxidants and provitamin A in crop plants. One of our current areas of research is the development of provitamin A-rich cassava to meet the nutritional demands of populations in sub-Saharan Africa (www.biocassavaplus.org).
Sphingolipids are major components of the plasma membrane and tonoplasts of plant cells and contribute to the ability of plants to respond to biotic and abiotic stresses. We are attempting to understand the synthesis and function of sphingolipids in Arabidopsis in order to produce higher yielding crops with improved stress tolerance. Recent publications from my lab have highlighted the importance of sphingolipids in pollen and endomembrane development. We have also shown that small modifications of sphingolipid structure in planta can result in enhanced production of sphingolipids with aberrant fatty acid chain lengths, which provides insights into the regulation of the biosynthesis of these essential lipids in plants.
Recent Papers
Ramamoorthy V, Cahoon EB, Thokala M, Kaur J, Li J, Shah DM (2009) Sphingolipid C9-methyltransferases are important for growth and virulence but not for sensitivity to antifungal plant defensins in Fusarium graminearum. Eukaryotic Cell 8:217-229.
Chen M, Markham JE, Dietrich CR, Jaworski JG, Cahoon EB (2008) Sphingolipid long-chain base hydroxylation is important for growth and for the regulation of sphingolipid content and composition in Arabidopsis. Plant Cell 20:1862-1878.
Dietrich CR, Han G, Chen M, Berg RH, Dunn TM, Cahoon EB (2008) Loss-of-function mutations and inducible RNAi suppression of Arabidopsis LCB2 genes reveal the critical role of sphingolipids in gametophytic and sporophytic cell viability. Plant Journal 54: 284-298 (cover article)
Cahoon EB, Schmid KM. (2008) Metabolic engineering of the content and fatty acid composition of vegetable oils. In Bioengineering and Molecular Biology of Plant Pathways. Advances in Plant Biochemistry and Molecular Biology, Vol. 1. Bohnert H, Nguyen H, Lewis N (eds). Elsevier, Burlington, MA, pp. 159-198.
Ramamoorthy V, Cahoon EB, Li J, Thokala M, Minto RE, Shah DM (2007) Glucosylceramide synthase is essential for alfalfa defensin-mediated growth inhibition but not for pathogenicity of Fusarium graminearum. Mol. Microbiol. 66: 771-786.
Cahoon EB, Shockey JM, Dietrich CR, Gidda SK, Mullen RT, Dyer JM (2007) Engineering oilseeds for sustainable production of industrial and nutritional feedstocks: solving bottlenecks in fatty acid flux. Curr. Opin. Plant. Biol. 10: 236-244.
Hunter SC, Cahoon EB (2007) Enhancing vitamin E in oilseeds: unraveling tocopherol and tocotrienol biosynthesis. Lipids 42: 97-108.
Chen M, Han G, Dietrich CR, Dunn TM, Cahoon EB (2006) The essential nature of sphingolipids in plants as revealed by the functional identification and characterization of the Arabidopsis LCB1 subunit of serine palmitoyltransferase. Plant Cell 18: 3576-3593.
Lohman A, Schottler MA, Brehelin C, Kessler F, Block R, Cahoon EB, Dörmann P (2006) Deficiency in phylloquinone (vitamin K1) methylation affects prenylquinine distribution, photosystem I abundance and anthocyanin accumulation in the Arabidopsis AtmenG mutant. J. Biol. Chem. 281: 40461-40472.
Kaewsuwan S, Cahoon EB, Perroud P-F, Wiwat C, Panvisavas N, Quatrano RS, Cove DJ, Bunyapraphatsaran N (2006) Identification and functional characterization of the moss Physcomitrella patens (Hedw.) B.S.G. ?5-desaturase gene involved in arachidonic and eicosapentaenoic acids biosynthesis. J. Biol. Chem. 281:21988-21997.
Cahoon EB, Dietrich CR, Meyer K, Damude HG, Dyer JM, Kinney AJ (2006) Conjugated fatty acids accumulate to high levels in phospholipids of metabolically engineered soybean and Arabidopsis seeds. Phytochemistry 67: 1166-1176.
Markham JM, Li J, Cahoon EB, Jaworski JG (2006) Plant sphingolipids: separation and identification of major sphingolipid classes from leaves. J. Biol. Chem. 281: 22684-94.
Eckert H, LaVallee B, Schweiger BJ, Kinney AJ, Cahoon EB, Clemente T (2006) Co-expression of the borage ?6 desaturase and the Arabidopsis ?15 desaturase results in high accumulation of stearidonic acid in the seeds of transgenic soybean. Planta 224: 1116-1128.
Paul S, Gable K, Beaudoin F, Cahoon E, Jaworski J, Napier JA, Dunn TM (2006)
Members of the Arabidopsis FAE1-like 3-ketoacyl-CoA synthase gene family substitute for the elop proteins of Saccharomyces cerevisiae. J. Biol. Chem. 281: 9018-9029.
Whittle E, Cahoon EB, Subrahmanyam S, Shanklin J (2005) A multifunctional acyl-acyl carrier protein desaturase from Hedera helix L. (English ivy) can synthesize 16- and 18-carbon monoene and diene products. J. Biol. Chem. 280: 28169-28176.
Ashok J, Marillia EF, Vivijan B, Michael GE, Cahoon EB, Kinney AJ, Taylor DC (2005) Production of 22:2?5,13 and 20:1?5 in Brassica carinata and soybean breeding lines via introduction of Limnanthes genes. Mol. Breeding 15: 157-167.
Arkus K, Cahoon EB, Jez JM (2005) Kinetic characterization of wheat chlorophyllase reveals a mechanistic connection to the carboxylesterase enzyme family. Arch. Biochem. Biophys. 438: 146-155.
Schmidt MA, Dietrich CR, Cahoon EB (2004) Biotechnological enhancement of soybean oil for lubricant applications. In Synthetic, Mineral Oil, and Bio-Based Lubricants: Chemistry and Technology (Ed. Rudnick L). CRC Press, Boca Raton, FL, pp 389-397.
Cahoon EB, Kinney AJ (2004) Dimorphecolic acid is synthesized by the coordinate activities of two divergent ?12-oleic acid desaturases. J. Biol. Chem. 279: 12495-12502.
Cahoon EB, Hall SE, Ripp KG, Ganzke TS, Hitz WD, Coughlan SJ (2003) Metabolic redesign of vitamin E biosynthesis in plants for tocotrienol production and increased antioxidant content. Nature Biotechnology 21: 1082-1087.
Sattler SE, Cahoon EB, Coughlan SJ, DellaPenna D (2003) Characterization of tocopherol cyclases from higher plants and cyanobacteria. evolutionary implications for tocopherol synthesis and function. Plant Physiol. 132: 2184-2195.
Cahoon EB, Schnurr JA, Huffman EA, Minto RE (2003) Fungal responsive fatty acid acetylenases occur widely in evolutionarily distant plant families. Plant J. 34: 671-683.
Jaworski J, Cahoon EB (2003) Industrial oils from transgenic plants. Curr. Opin. Plant Biol. 6: 178-184.
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