Scientists Find Key Genes for Oil Surge in Plant Leaves

Scientists at the US Department of Energy's Brookhaven National Laboratory have identified two key genes required for oil production and accumulation in plant leaves and other vegetative plant tissues.

The new finding, published in separate papers in the journals The Plant Journal and The Plant Cell, could have important implications for increasing the energy content of plant-based foods and renewable biofuel feedstocks.

The Brookhaven research aims to reprogram plants to store the energy-dense oil compound known as triacylglycerol (TAG) in their leaves and vegetative tissues, the most abundant sources of plant biomass. The researchers reported that overexpression of the gene for the enzyme phospholipid diacylglycerol acyltransferase 1 (PDAT1) resulted in higher TAG content, present as oil droplets, in the leaves of Arabidopsis thaliana plants. The researchers also activated the gene for oleosin along with PDAT1 to boost leaf oil content by up to 6.4 percent of the dry weight without affecting membrane lipid composition and plant growth. Oleosin is a protein that prevents oil droplets from fusing together, keeping them smaller while also protecting the oil inside. 

The scientists used radio-labeled carbon (C-14) to identify the biochemical mechanism by which PDAT increases oil production. They traced the uptake of C-14-labeled acetate into fatty acids, the building blocks of membrane lipids and oils. These results showed that PDAT increased the rate at which these fatty acids were made.