Class A lysophosphatidic acid acyltransferase 2 from Camelina sativa promotes very long-chain fatty acids accumulation in phospholipid and triacylglycerol.

Abstract

Very long-chain fatty acids (VLCFAs) are important industrial raw materials and can be produced by genetically modified oil plants. For a long time, class A lysophosphatidic acid acyltransferase (LPAT) was considered unable to promote the accumulation of VLCFA in oil crops. The bottlenecks that the transgenic high VLCFA lines have an oil content penalty and the low amount of VLCFA in phosphatidylcholine remains intractable. In the present study, a class A LPAT2 from Camelina sativa (CsaLPAT2) promoting VLCFAs accumulation in phospholipid was found. Overexpression of CsaLPAT2 alone in Arabidopsis seeds significantly increased the VLCFA content in triacylglycerol, including C20:0, C20:2, C20:3, C22:0, and C22:1. The proportion of phosphatidic acid molecules containing VLCFAs in transgenic seeds reached up to 45%, which was 2.8-fold greater than that in wild type. The proportion of phosphatidylcholine and diacylglycerol molecules containing VLCFAs also increased significantly. Seed size in CsaLPAT2 transgenic lines showed a slight increase without an oil content penalty. The total phospholipid content in the seed of the CsaLPAT2 transgenic line was significantly increased. Furthermore, the function of class A LPAT in promoting the accumulation of VLCFAs is conserved in the representative oil crops of Brassicaceae, such as C. sativa, Arabidopsis thaliana, Brassica napus, Brassica rapa, and Brassica oleracea. The findings of this study provide a promising gene resource for the production of VLCFAs.