This article first appeared in the St. Louis Beacon, Dec. 2, 2009 - In the Wall Street Journal, I read that Beijing has given the nod to genetically modified rice, declaring the rice safe to produce and consume. After years of lab tests and field trials, China recently issued safety certificates for two strains of GM rice produced by Chinese agricultural scientists. It will be two or three years before the new GM rice is produced commercially, as scaling up production requires careful engineering, but this approval was the key hurdle. GM rice will soon be part of China's future.
Over the past 15 years the cultivation of genetically modified (GM) crops of corn, cotton, soybeans and other plants has become commonplace in the United States. As far back as five years ago, in 2003, the revolution was already complete: 84 percent of soybeans in the United States were planted with seeds genetically modified to be herbicide resistant. The result has been that less tillage was needed and, as a consequence, soil erosion was greatly lessened.
Pest-resistant GM corn in 2003 comprised 38 percent of all corn planted in the United States, and pest-resistant GM cotton comprised 81 percent of all cotton. In both cases, the change greatly lessens the amount of chemical pesticide used in raising the crops. These benefits of soil preservation and chemical pesticide reduction, while significant, have been largely bestowed upon farmers, making their cultivation of crops cheaper and more efficient, and so increasing production.
Like the first act of a play, these developments have served mainly to set the stage for the real action, which is only now beginning to happen. The real promise of plant genetic engineering is to produce genetically modified plants with desirable traits that directly benefit the consumer.
Unlike the GM corn, cotton and soybeans grown widely in this country, Europe, and South America, genetically modified rice is not being grown on a major scale anywhere today, so this week's announcement in China marks a real turning point.
I was disheartened to note, however, that China seems to have followed the same path taken by Monsanto and other gene technology agricompanies in the United States and Europe - the genes being modified in Chinese GM rice are ones increasing resistance to pests and herbicides. While such changes will surely appeal to farmers wishing to boost output, I firmly believe that this is the wrong first step. I am sure GM crops would not be so controversial in our country if Monsanto had chosen to start its GM crop revolution by modifying crop genomes to improve nutritional value for consumers, instead of chasing shorter-term profits by helping farmers increase production.
Placing improved profitability over improved quality was the key mistake of the agricultural GM revolution, in my judgment. It is a mistake that did not have to be made again in China, because gene modifications of rice that greatly improve the crop have already been developed and await commercial implementation. Two leap immediately to mind: flood-tolerant rice and so-called "golden rice."
I wrote about the development of flood-tolerant rice in this column nine months ago. Developed in 2006 by U.C. Davis Professor Pamela Ronald, the new gene-modified rice strains have the potential to avoid famine, no small benefit. For centuries, death has stalked subsistence farmers in China because the rice they grow cannot tolerate being under water more than a day or so. A flood of several days simply kills the crop, starvation the only harvest. For rural Chinese farmers, the rice crops on which their lives depend have always been threatened by floods they cannot predict, prevent or control.
The solution, however, proves simple and effective. Dr. Ronald has inserted one crucial gene that makes the rice traditionally grown in China tolerant of flooding, erasing in a single step the whole problem. Her advance awaits commercial development, a major financial commitment for any agricultural firm (or any country, for that matter). To see China proceeding to improve the pest and herbicide resistance of its commercial rice and not make this change makes me gnash my teeth.
The second major opportunity for China to improve the nutritional quality of its rice crop will be well known to many of my readers: so-called "golden" rice. In developing countries like China, large numbers of people live on simple diets that are poor sources of vitamins and minerals. Worldwide, the two major deficiencies are iron, which affects 1.4 billion women (24 percent of the world population) and vitamin A, affecting 40 million children (7 percent of the world population). The deficiencies are especially severe in developing countries where the major staple food is rice.
In recent research, Swiss bioengineer Ingo Potrykus and his team at the Institute of Plant Sciences, Zurich, have gone a long way toward solving this problem. Supported by the Rockefeller Foundation and with results to be made free to developing countries, the work is a model of what plant genetic engineering can achieve.
To solve the problem of dietary iron deficiency among rice eaters, Potrykus first asked why rice is such a poor source of dietary iron. The problem, and the answer, proved to have three parts:
- Too little iron. The proteins of rice endosperm have unusually low amounts of iron. To solve this problem, a ferritin gene was transferred into rice from beans. Ferritin is a protein with an extraordinarily high iron content, and so greatly increased the iron content of the rice.
- Inhibition of iron absorption by the intestine. Rice contains an unusually high concentration of a chemical called phytate, which inhibits iron reabsorption in the intestine -- it stops your body from taking up the iron in the rice. To solve this problem, a gene encoding an enzyme called phytase that destroys phytate was transferred into rice from a fungus.
- Too little sulfur for efficient iron absorption. The human body requires sulfur for the uptake of iron, and rice has very little of it. To solve this problem, a gene encoding a sulfur-rich metallothionin protein was transferred into rice from wild rice.
To solve the problem of vitamin A deficiency, the same approach was taken. First, the problem was identified. It turns out rice only goes partway toward making beta-carotene (provitamin A); there are no enzymes in rice to catalyze the last four steps. To solve the problem, genes encoding these four enzymes were added to rice from a flower, the daffodil.
The added nutritional value of Potrykus' golden rice only makes up for half a person's requirements, but it is a promising start, representative of the very real promise of plant genetic engineering.
Thus while I applaud China for embarking on an enterprise to improve its commercial rice, I wish its effort was to be more audacious. Why not take advantage of Ronald's work with flood-tolerant rice, or Potyrykus's work with golden rice? Seeking improved quality as well as increased production could only work to the benefit of China's people, and the key developmental work has already been done.
Not only am I a great Monday-morning quarterback and superb back-seat driver, as you can see here, I am really good at assessing what other countries should do with their scientific decisions. To date, China does not seem to be paying me much attention.
Free rice
While you chew on all this, want to do your little bit to help more rice reach the mouths that need it? The "Free Rice Game" on the internet (www.freerice.com ) asks you quiz questions.
For each answer you get right, 20 grains of rice are donated to the U.N. World Food Program to help end hunger. Since its inception in October 2007, more than 50 billion grains of rice have been donated, about 20 million grains a day.
For each answer you get right, you then get a harder question to attempt. How many questions in a row do you think you can get right (the average is four)?
George B. Johnson's "On Science" column looks at scientific issues and explains them in an accessible manner.
Johnson, Ph.D., professor emeritus of Biology at Washington University, has taught biology and genetics to undergraduates for more than 30 years. Also professor of genetics at Washington University’s School of Medicine, Johnson is a student of population genetics and evolution, renowned for his pioneering studies of genetic variability. He has authored more than 50 scientific publications and seven texts.
As the founding director of The Living World, the education center at the St Louis Zoo, from 1987 to 1990, he was responsible for developing innovative high-tech exhibits and new educational programs.
Copyright George Johnson