Photosynthesis-driven membrane lipid biosynthesis under high-light stress

August 26, 2025

Toward engineering lipid composition in photosynthetic organisms

A collaborative research group from Saitama University and the RIKEN CSRS has uncovered a molecular mechanism by which photosynthetic organisms respond to high-light stress through membrane lipid remodeling. The study revealed that under high-light conditions, thylakoid membranes undergo lipid conversion, leading to an increase in the phospholipid phosphatidylglycerol (PG). Furthermore, the team successfully identified the enzyme responsible for this increase, diacylglycerol kinase (DGK). These findings suggest that controlling the metabolic pathways that regulate the balance between phospholipids and glycolipids could enable targeted biosynthesis of desired lipids. This may further contribute to the enhanced production of lipid-derived hormones and biofuels.

Photosynthetic organisms optimize their photosynthetic activity in response to environmental stress. It has been hypothesized that changes in thylakoid membrane lipid composition—triggered by factors such as high-light intensity or low CO₂—play a role in regulating photosynthesis. However, the molecular mechanisms underlying these changes have remained unclear. Using cyanobacteria as a model, the researchers demonstrated that PG levels increase under high-light stress and identified DGK as a key enzyme involved in this process. In future, elucidating the mechanisms of membrane lipid remodeling under various environmental stresses could pave the way for developing photosynthetic systems with improved stress tolerance and increased yields of valuable lipids.

 

Original article

The Plant Journal　doi: 10.1111/tpj.70368

K. Takagi, Y. Nakamura, H. Jimbo, H. Wada,

"Cyanobacterial diacylglycerol kinase is involved in membrane lipid synthesis and contributes to high-light acclimation of photosystem II".

Contact

Yuki Nakamura
Team Director
Plant Lipid Research Team