It all began in 1984 over beers at an international agricultural meeting in the Philippines. Gary Toenniessen of the Rockefeller Foundation asked a group of plant scientists this question: how can we use the new technology of genetic engineering to improve rice? Since rice is the principal food staple for billions of people, making it more nutritious would benefit a significant percentage of the world’s population, including many in underdeveloped countries.
The scientists put their heads together and agreed on the answer: engineer rice so that it can be a source of vitamin A. This idea immediately generated great enthusiasm. Why? At least 750 million children in the world have diets that are deficient in vitamin A. Vitamin A deficiency (VAD) can lead to terrible consequences. According to the World Health Organization (WHO), 250,000 to 500,000 children go blind every year because VAD damages eyes. Half these children may die each year because VAD also increases susceptibility to many infectious diseases.
Vitamin A is found in many foods: carrots, tomatoes, meat, and milk, for example. But many economically disadvantaged people do not have access to balanced nutrition, and among these people VAD is a persistent problem. Most cases of VAD occur in parts of Asia, where rice is the major source of calories. Rice fortified with vitamin A could reduce malnourishment and help save lives.
At least 750 million children in the world have diets that are deficient in vitamin A, but in countries with high GDP, this deficiency is not of public health significance. Insufficient vitamin A in the diet can lead to serious health problems, including xerophthalmia; left untreated, this disorder may lead to blindness.
It’s a long journey from an idea hatched over beers to a scientific payoff. At the time, the only way to get rice to make a biochemical precursor of vitamin A was to take genes from a species that can make it and insert them into rice—a formidable task. When eaten, this precursor can be converted into Vitamin A by the body. Toenniessen’s question lay on the table for almost a decade. A chance meeting provided the spark needed for the answer.
Ingo Potrykus, a German scientist living in Switzerland, and Peter Beyer, a German scientist living in Germany, met in 1992 on a plane as they traveled to New York City to attend a conference organized by the Rockefeller Center. Potrykus was an expert at manipulating genes in rice, and Beyer was a specialist in the biochemistry of vitamin A production. They realized that their complementary specialties put them in a unique position to solve the problem of making rice a source of vitamin A.
Together they wrote an ambitious proposal to insert the genes for making vitamin A into rice seeds. The Rockefeller Foundation took a chance and funded them. And in 1999, golden rice was born.
Potrykus and Beyer pioneered many techniques and made discoveries that advanced the emerging field of genetic engineering. However, the genetic engineering used to develop golden rice and other crops has raised complex questions about safety, ethics, and other considerations. In this chapter, we will examine how genetic engineering works and how these techniques are being applied. We will also address an important social issue: what should we do with our new creative powers? But first we will take a look at how plants work, to better understand why they make such good targets for genetic engineering.