New metabolic pathway for the synthesis of seed oil is discovered

sdgs Icon2 sdgs Icon3 sdgs Icon13 sdgs Icon15

April 4, 2022

Application to the technology for improving metabolism that helps create biofuels is expected

An international collaborative research team of the RIKEN CSRS, Institute of Plant and Microbial biology, Academia Sinica, and National Chung Hsing University in Taiwan discovered a new metabolic pathway for synthesizing the major component of seed oil, triacylglycerol (TAG).

TAG is synthesized from phosphatidylcholine (PC), the most primary class of phospholipids that constitutes cell membranes. However, the mechanism of how the second most abundant class of phospholipids, phosphatidylethanolamine (PE), converts to TGA has remained unclear.

Focusing on the enzyme that converts PE directly into PC in yeast and the human liver, the international collaborative team found phospholipid N-methyltransferase (PLMT) in the model plant Arabidopsis, an enzyme that functions similarly. Overexpression of PLMT in planta increased the TAG content in the seed by up to 20% per dry weight. The researchers also found that PLMT overexpression inhibits the growth of leaves, suggesting that this metabolic pathway might be specific to the TAG synthesis of seeds. These results revealed that PLMT contributes to the TAG synthesis by converting PE to PC.

The findings of this study would contribute to metabolic engineering for the mass production of feedstocks such as biodiesel in planta.

Original article
Journal of Experimental Botany doi:10.1093/jxb/erac049
Y. Tan, Y. Nakamura,
"The importance of Arabidopsis PHOSPHOLIPID N-METHYLTRANSFERASE(PLMT) in glycerolipid metabolism and plant growth".
Yuki Nakamura
Team Leader
Plant Lipid Research Team