Production of a Brassica napus Low-Molecular Mass Acyl-Coenzyme A-Binding Protein in Arabidopsis Alters the Acyl-Coenzyme A Pool and Acyl Composition of Oil in Seeds

Olga Yurchenko; Stacy D Singer; Cory L Nykiforuk; Satinder Gidda; Robert T Mullen; Maurice M Moloney; Randall J Weselake

doi:10.1104/pp.114.238071

Production of a Brassica napus Low-Molecular Mass Acyl-Coenzyme A-Binding Protein in Arabidopsis Alters the Acyl-Coenzyme A Pool and Acyl Composition of Oil in Seeds

Plant Physiol. 2014 Jun;165(2):550-560. doi: 10.1104/pp.114.238071. Epub 2014 Apr 16.

Authors

Olga Yurchenko¹, Stacy D Singer¹, Cory L Nykiforuk¹, Satinder Gidda¹, Robert T Mullen¹, Maurice M Moloney¹, Randall J Weselake²

Affiliations

¹ Agricultural Lipid Biotechnology Program, Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5 (O.Y., S.D.S., R.J.W.);SemBioSys Genetics, Calgary, Alberta, Canada T1Y 7L3 (C.L.N., M.M.M.); andDepartment of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (S.G., R.T.M.).
² Agricultural Lipid Biotechnology Program, Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5 (O.Y., S.D.S., R.J.W.);SemBioSys Genetics, Calgary, Alberta, Canada T1Y 7L3 (C.L.N., M.M.M.); andDepartment of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (S.G., R.T.M.) randall.weselake@ualberta.ca.

Abstract

Low-molecular mass (10 kD) cytosolic acyl-coenzyme A-binding protein (ACBP) has a substantial influence over fatty acid (FA) composition in oilseeds, possibly via an effect on the partitioning of acyl groups between elongation and desaturation pathways. Previously, we demonstrated that the expression of a Brassica napus ACBP (BnACBP) complementary DNA in the developing seeds of Arabidopsis (Arabidopsis thaliana) resulted in increased levels of polyunsaturated FAs at the expense of eicosenoic acid (20:1^cisΔ11) and saturated FAs in seed oil. In this study, we investigated whether alterations in the FA composition of seed oil at maturity were correlated with changes in the acyl-coenzyme A (CoA) pool in developing seeds of transgenic Arabidopsis expressing BnACBP. Our results indicated that both the acyl-CoA pool and seed oil of transgenic Arabidopsis lines expressing cytosolic BnACBP exhibited relative increases in linoleic acid (18:2^cisΔ9,12; 17.9%-44.4% and 7%-13.2%, respectively) and decreases in 20:1^cisΔ11 (38.7%-60.7% and 13.8%-16.3%, respectively). However, alterations in the FA composition of the acyl-CoA pool did not always correlate with those seen in the seed oil. In addition, we found that targeting of BnACBP to the endoplasmic reticulum resulted in FA compositional changes that were similar to those seen in lines expressing cytosolic BnACBP, with the most prominent exception being a relative reduction in α-linolenic acid (18:3^cisΔ9,12,15) in both the acyl-CoA pool and seed oil of the former (48.4%-48.9% and 5.3%-10.4%, respectively). Overall, these data support the role of ACBP in acyl trafficking in developing seeds and validate its use as a biotechnological tool for modifying the FA composition of seed oil.