Researchers from the Biotechnology Foundation Laboratories at Thomas Jefferson University have found a way to increase the oil in tobacco plant leaves, which may be the next step in using the plants for biofuel.

According to Vyacheslav Andrianov, assistant professor of Cancer Biology at Jefferson Medical College, tobacco can generate biofuel more efficiently than other agricultural crops.

“Tobacco is very attractive as a biofuel because the idea is to use plants that aren’t used in food production,” Andrianov said.

However, most of the oil is typically found in the seeds – which are composed of about 40 percent oil per dry weight. Although the seed oil has been tested for use as fuel for diesel engines, tobacco plants yield a modest amount of seeds, at only about 600 kg of seeds per acre.

“We have found ways to genetically engineer the plants so that their leaves express more oil,” Andrianov explained.

Typical tobacco plant leaves contain 1.7 percent to 4 percent of oil per dry weight. The new plants were engineered to overexpress one of two genes: the diacyglycerol acytransferase (DGAT) gene or the LEAFY COTYLEDON 2 (LEC2) gene. The DGAT gene modification led to about 5.8 percent of oil per dry weight in the leaves - about two-fold the amount of oil produced normally. The LEC2 gene modification led to 6.8 percent of oil per dry weight.

“Based on these data, tobacco represents an attractive and promising ‘energy plant’ platform, and could also serve as a model for the utilization of other high-biomass plants for biofuel production,” Andrianov said.

(Thomas Jefferson University)