A research team at the Brookhaven National Laboratory (BNL) of the US Department of Energy has uncovered a way to boost plant oil production by disabling a biomolecule acting as a productive ‘handbrake’.
The results of the study suggested that deactivating the particular molecule could push oil production in a plant into high gear, which could lead to more abundant biofuel and plant-based bioproducts, a 9 April statement from the BNL said.
Lead researcher John Shanklin said it was normal for plant cells to cut back on oil production when they were fed an excess of fatty acids, as Shanklin’s team had discovered in another study in 2012.
However, while studying how exactly plants down-regulated their oil production, the team discovered by surprise that the biological brakes were also partially active even under normal conditions.
“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. That’s what we’ve just discovered for plant oil production,” said Shanklin.
The enzyme in question, known as ACCase, is a protein made up of four sub units, which all are required for the enzyme to function.
The ACCase drives the first step in the synthesis of fatty acids, key components of what will eventually become plant oil.
In the 2012 study, Shanklin and his team confirmed that feeding a plant an excessive amount of fatty acid for a short period inhibited ACCase, decreasing oil production, while a longer-term diet would disable it for good.
In 2016, a team at the University of Missouri discovered an inactive version of one of the four enzyme sub units and Shanklin suspected that this inactive unit could be the cause of the permanent shutdown by taking the place of one of the original active sub units in ACCase.
Shanklin’s team ran tests on plants where the inactive sub units were individually disabled, which were bred with plants that had the same units active.
“We suspected that disabling the genes would turn off the off-switch for oil production, allowing the plant cells to make more oil,” said Shanklin.
The result was exactly what the team had expected but, in addition, they noticed that cells with the disabled inactive sub units were producing more oil even when they were not fed the high-fatty acid diet.
“This means that, even under normal conditions, inactive sub units are putting the brakes on ACCase, reducing its activity and limiting oil production,” Shanklin explained.
The discovery, according to BNL, could potentially lead to strategies to increase oil accumulation and production in plants used for the production of vegetable oils.