Science-- there's something for everyone

Sunday, April 18, 2010

Orange ears

Torbert Rocheford and his team from Purdue University have been breeding orange ears of corn. The orange corn is high in carotenoids, such as beta-carotene, which humans convert into vitamin A.

The intense orange color of high pro-vitamin A maize is caused by high carotenoid content.

Credit: Purdue University photo/Debra J. Skinner

Vitamin A deficiency causes up to 500,000 children to go blind worldwide each year, half of whom die within the first year. The researchers hope that the new type of corn, among other enhanced grains, will prevent these tragedies.

The scientists didn’t simply pick the orangest ears of corn for breeding, however. They focused on a gene called ‘beta-carotene hydroxylase 1’ (crtR-B1). When highly active, this gene, through a series of steps including hydroxylation, decreases the amount of beta-carotene in the corn. For this reason, the researchers are careful to select ears that display little crtR-B1 activity for dissemination to parts of the world where children suffer from vitamin A deficiency.

On the other hand, although crtR-B1 decreases the amount of beta-carotene, the gene actually increases the amount of zeaxanthin in the corn. Zeaxanthin is a major component of the central macula of the human eye. Thus, active crtR-B1 could protect people from macular degeneration, the leading cause of blindness in seniors living in industrialized nations.

Ultimately, Rocheford and his team hope to be able to prevent blindness in the young and the old by tailoring their orange ears of corn to fit particular needs. In the meantime, I can think of someone who’d be pretty happy to find this offering on the dinner menu. You know who you are.