The present public pressure on ag-biotech companies is very helpful in this respect. They feel they should be doing something for their good name in public relations. Potrykus and his collaborators used agricultural biotechnology to solve a problem that could not be solved through conventional crossbreeding. Rice can make beta carotene in its leaves, but no variety is known to make it in the edible endosperm. So Potrykus used modern techniques of genetic manipulation to insert genes from the daffodil that encode the biological machinery for production of beta carotene.
Beta carotene is the substance that makes carrots orange.
The lower concentrations in Potrykus's rice give it a delicate golden hue. The human body readily converts beta carotene into Vitamin A, ensuring an adequate supply of that vital nutrient. Vitamin A deficiency can lead not only to blindness but also to severe immune deficiency, making a malnourished person prey to numerous diseases. Figures compiled by the Rockefeller Foundation suggest that about 400 million people in poor countries suffer Vitamin A deficiency every year, and it's serious enough in about half of them to impair their immune systems. Between 1 million and 2 million die every year of infections and other diseases that exploit the deficiency, and hundreds of thousands more go permanently blind.