Agricultural Genetic Awesomeness

[by Naveen]

Genetically modified foods have gotten a lot of bad press lately and it's too bad they don't have a better PR effort behind them. Most people are opposed to GMO due to knee-jerk associations with global corporate agriculture and view it as the anti-thesis of the locavore trend. This misses out on the efforts of plant biologists and farmers in countries ranging from Mexico to the Philippines to Australia to produce crops that are drought-resistant, salt-tolerant, and safe from the latest viral or bacterial threat (see here, for example). It has also been criticized for being over-hyped about its ability to feed the world. After several weeks of researching these arguments, I tend to agree and suspect that better farmer education and food distribution in rural areas will be more important.

I learned all this while preparing for a public talk last week for the Science in the News lecture series. Two other grad students and I explained the history and biology of agricultural genetics, presented some case studies (Bt Corn and Golden Rice), then explored the role of genetically-engineered foods in solving world hunger (that was my part). While researching this topic, for which I felt increasingly under-qualified, I talked to Peace Corps volunteers, farmers, and Friends of the World Food Program. There is so much more to the history of edible plant biology than gets mentioned in the highly-polarized debate about GM Foods, so I thought I would share some of my findings:

• Wide crossing allows two different species of plants to breed with each other. The plant isn't too happy about this and tries to eject the hybrid embryo, but scientists can rescue it and grow it up in vitro to a viable new plant. Scientists did this in the 1970s to save the Asian rice crop from the grassy stunt virus.
• A floral toxin called colchicine causes a plant cell to double its number of chromosomes by messing with its microtubules (similar chemicals are sometimes used as anti-cancer drugs). The confused plant cells often end up producing seedless adults (e.g. watermelon, grapes). This chromosome doubling method was also used to create tritacle, a wheat-rye hybrid that I first learned about from a Kashi cereal box.
• During the pro-nuke days of the 1950s and '60s, a collaboration between the FAO and the IAEA sent out portable radiation sources to farms all over the world. By irradiating, for instance, 100,000 seeds, the second generation might have 30-50,000 adults, which can be whittled down to a few beneficial mutants. Supposedly much of the organic beer in Europe comes from barley that was a product of radiation mutagenesis.

The wide-crossing, chromosome doubling, and radiation mutagenesis are all decades old and (to the best of my knowledge) can still fall under the label organic. In fact, there was a debate in the late '90s about whether new genetic techniques would fall under the USDA certification, since they would not require external inputs like fertilizer or pesticides. For their credit, genetically modified organisms have done several good things for us lately, including producing insulin for treating diabetics and vegetarian rennet for making cheese.

For more info, I recommend these two books:

• "Tomorrow's Table: Organic Farming, Genetics, and the Future of Food" by Pamela Ronald and R. W. Adamchak.
• "Plant Breeding and Biotechnology: Social Context and the Future of Food" by Denis Murphy.

I'm sure there are countless other resources out there and I encourage you to learn more about this fascinating topic. Please let me know if you find out anything else interesting.