Biofuel Breakthrough? Scientists Modify Plants to Store Oil in Leaves

Chubby caterpillars show that scientists have engineered a plant with oily leaves, an advance that could enhance biofuel production and lead to improved food for animals.

The results, published in the current issue of The Plant Cell, show that researchers could use an algae gene involved in oil production to engineer a plant that stores lipids or vegetable oil in its leaves-an uncommon occurrence for most plants.

Traditional biofuel research has focused on improving the oil content of seeds, in part because oil production in seeds occurs naturally. Little research, however, has been done to examine the oil production of leaves and stems, as plants don't typically store lipids in these tissues.

Christoph Benning, professor of biochemistry and molecular biology at Michigan State University, led a collaborative effort with colleagues from the Great Lakes Bioenergy Research Center (GLBRC).

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"Many researchers are trying to enhance plants' energy density, and this is another way of approaching it," Benning says. "It's a proof-of-concept that could be used to boost plants' oil production for biofuel use as well as improve the nutrition levels of animal feed."

Benning and his colleagues began by identifying five genes from one-celled green algae. From the five, they identified one that, when inserted into Arabidopsis thaliana, successfully boosted oil levels in the plant's leaf tissue.

To confirm that the improved plants were more nutritious and contained more energy, the research team fed them to caterpillar larvae. The larvae that were fed oily leaves from the enhanced plants gained more weight than worms that ate regular leaves.

For the next phase of the research, Benning and his colleagues will work to enhance oil production in grasses and algae that have economic value. The benefits of this research are worth pursuing, Benning says.

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"If oil can be extracted from leaves, stems, and seeds, the potential energy capacity of plants may double," he says. "Further, if algae can be engineered to continuously produce high levels of oil, rather than only when they are under stress, they can become a viable alternative to traditional agricultural crops."

Moreover, algae can be grown on poor agricultural land-a big plus in the food vs. fuel debate, he adds.

"These basic research findings are significant in advancing the engineering of oil-producing plants," says Kenneth Keegstra, GLBRC scientific director and professor of biochemistry and molecular biology.

"They will help write a new chapter on the development of production schemes that will enhance the quantity, quality, and profitability of both traditional and nontraditional crops."

By. Layne Cameron