A team led by Dr. Yuki Nakamura, an Assistant Research Fellow at the Institute of Plant and Microbial Biology recently discovered that a novel enzyme choline/ethanolamine kinase 4 (CEK4) is crucial in seed development and oil production in the model plant Arabidopsis thaliana. They found that a mutation in CEK4 severely affects seed development, and overexpression of CEK4 increases oil in the mature seeds. The study conceptually advances understanding of seed oil biosynthesis, and may contribute to new metabolic engineering strategies to improve seed oil content in crops. The research was published in the journal The Plant Cell on May 12, 2015.

　　Plant seeds contain a high level of oil that is an essential energy source during dormancy, germination and early seedling growth. Triacylglycerol (TAG) is a representative seed storage oil that is also a source for biodiesel production. Although membrane phospholipids are considered primary precursors for TAG biosynthesis, their connection remains elusive because the initial reaction steps of phospholipid biosynthesis are obscure.

　　Dr. Nakamura’s team hypothesized that the choline/ethanolamine kinase (CEK) gene may play a critical role in the initial step of phospholipid biosynthesis. Among 4 candidate genes for CEK, mutation in CEK4 severly affected seed development. Moreover, a transgenic plant overexpressing CEK4 increased phospholipids by 1.5-fold and triacylglycerol by 2-fold in the mature seeds. Thus, Nakamura’s team concluded that CEK4 is a critical enzyme in the initial step of phospholipid biosynthesis, which is crucial for seed development and oil production in Arabidopsis thaliana.

　　The research was funded by the core operation budget provided by Institute of Plant and Microbial Biology, Academia Sinica.

　　The complete list of authors is: Ying-Chen Lin, Yu-chi Liu and Yuki Nakamura.

　　The complete article entitled “Choline/ethanolamine kinase (CEK) family in Arabidopsis: Essential role of CEK4 in phospholipid biosynthesis and embryo development” can be found at 　　The Plant Cell journal website at:　http://www.plantcell.org/content/early/2015/05/12/tpc.15.00207.abstract