"A Unique Acyl-Acyl Carrier Protein Fatty Acid Desaturase Gene from Pelargonium"

Inventors: R. Craig, et al.

PSU Invention Disclosure No. 95-1468

Licensing Contact: Ronald J. Huss

U.S. Issued Patent No. 5,856,157

Penn State researchers have identified, sequenced and characterized a novel plant fatty acid desaturase gene and the associated enzyme responsible for formation of certain unsaturated fatty acids. The gene was isolated from pest-resistant strains of the common garden geranium (Pelargonium xhortorum). The gene codes for a D ⁹ 14:0-ACP fatty acid desaturase. This enzyme places a double bond at the D ⁹ position of 14:0-ACP fatty acid substrate thereby producing the D ⁹ 14:1 unsaturated fatty acid. Many plants, including geraniums, efficiently elongate this unsaturated fatty acid to two unique fatty acids, D ¹¹ 16:1 and D ¹³ 18:1. In geraniums, these two unique fatty acids are further processed by known pathways to form w ⁵ 22:1 and w ⁵ 24:1 anacardic acids. These anacardic acids are responsible for resistance to certain pests (spider mites and aphids) in geraniums.

The D ⁹ 14:0-ACP fatty acid desaturase gene has been cloned into E. coli. The resulting recombinant protein has similar enzyme activity in E. coli as it has in geraniums. E. coli expressing the cloned desaturase gene produce D ⁹ 14:1 fatty acid which does not accumulate, but rather is efficiently elongated to form two unsaturated fatty acids, D ¹¹ 16:1 and D ¹³ 18:1, which do accumulate. These two fatty acids do not occur naturally in E. coli.
The D ⁹ 14:0-ACP fatty acid desaturase gene has a number of potential commercial applications including:

• Modifying the fatty acid and oil composition of economically important seed crops including soybeans, rapeseed, corn, sunflower, safflower, cotton, peanut, coconut and palm.


• Increasing the unsaturated fatty acid content of economically important seed crops.


• Modifying pest resistance in plants.


• Designing/engineering non-edible oils.