Researchers from the U.S. Department of Energy's Brookhaven National
Laboratory revealed the biomolecules that can put brakes on oil production
of plants. When these biomolecular brakes are disabled, oil production could
be boosted which may lead to more biofuels and plant-derived bioproducts.
The results of the study are published in Plant Physiology.

"It's normal for plant cells to down-regulate oil production when we feed
them excess fatty acids, and this study confirms our hypothesis about how
they do that. But we also discovered that the brakes on oil production are
partially on even under normal conditions, which was a big surprise," said
John Shanklin, a biochemist and leader of the study. "It would be like
driving a car for several years and finding out one day that a parking brake
you didn't know about had been on all along. When you remove that brake, the
car has much more power; that's what we've just discovered for plant oil
production," he said.

The study puts the spotlight on the enzyme that determines the rate of oil
production. The enzyme, known as ACCase, is a protein made of four subunits,
all of which are necessary for the enzyme to function. The researchers
suspected that disabling the genes that code for the inactive subunits would
turn off the off-switch for oil production, allowing the plant cells to make
more oil. When they tested this idea by feeding the plant cells excess fatty
acids, that's exactly what happened: Cells with combinations of the disabled
genes didn't turn off oil production the way cells with the normal genes
did. This implies that, even under normal conditions, inactive subunits are
putting the brakes on ACCase, reducing its activity and limiting oil
production.

"Disabling the genes for those inactive subunits is like taking the brakes
off the car, revealing the motor's true potential," Shanklin said.

[www.bnl.gov]