June 28, 2006

 

US researchers develop biopharmaceutical corn

 

 

Researchers at Iowa State University are developing a corn variety that keeps the therapeutic protein without the pollens using traditional breeding methods.

 

ISU researchers said the biopharmaceutical corn have been used to treat bacterial diarrhea in pigs. Results so far have been promising.

 

Currently, the team is hoping to develop a male sterile corn that carries the transgene.

 

Since male sterile corn plants do not produce pollen, the new variety could be grown without worries of it pollinating traditional corn varieties.

 

Kendall Lamkey, who also directs the Raymond F. Baker Center for Plant Breeding, leads the breeding portion of the research. Kan Wang, the principal researcher who transformed the corn, is professor of agronomy and director of the Centre for Plant Transformation. Both centres are part of Iowa State's Plant Sciences Institute.

 

The researchers said it would take five growing seasons to make all the breeding crosses needed. The first season took place last winter in the Plant Sciences Institute's greenhouse. The biopharmaceutical corn was crossed with the non-transgenic, male-fertile corn line to produce a transgenic F1 hybrid.

 

Seeds from that cross are now used this summer in a field trial. No transgenic pollen would be shed in the trial. The transgenic crop would be detasseled and pollinated by surrounding non-transgenic corn.

 

The seed harvested in the fall would be used in the winter again in the greenhouse. Another field trial would be scheduled next summer.

 

The corn was engineered to produce LT-B, a protein subunit produced by some strains of E. coli. Research has shown the ability of the protein to stimulate protective immune antibodies.

 

Other Iowa State scientists are researching how the corn-based pharmaceutical can help protect livestock from bacterial infections.

 

The system being developed in corn would work with other proteins, Lamkey said, adding that corn is the preferred plant for producing proteins for non-food products.

 

Besides being easy to manipulate from a breeding perspective, the pollination process of corn can be controlled, unlike the self-pollinating soy, Lamkey said. The wealth of research information on corn also helped greatly in research.

 

Corn seed is a good reservoir for foreign protein, Wang said. Furthermore, allergic reaction to corn protein in plants and animals is virtually non-existent which made it an excellent choice for making biopharmaceutical proteins.