February 25, 2014

Attack of the Killer Tomatoes: A GMO story

Dr. David Holding, Assistant Professor Plant Molecular Genetics, Research in his laboratory focuses on understanding endosperm hardening during maturation and its relationship to protein quality in maize. 2010 photo for Center for Plant Science Innovation shoot. Photo by Craig Chandler / University CommunicationsBefore genetic modification, the alkaloid levels in that tomato on your BLT could have killed you. And instead of corn on the cob, you’d be eating a handful of birdseed.

Genetic management and selective breeding have been used for centuries (Gregor Mendel and Luther Burbank, anyone?). Today, we’re just doing it better.

As farmers and ranchers work to meet the daunting challenge of feeding an exploding global population, they continue to grow more with less – less water, less land, less fertilizer and pesticides, and less impact on the environment.

Currently, genetically modified (GM) crops—also referred to as “biotechnology”—are an important part of a farmer’s portfolio. But they are not an end-all solution.

“The research we do is not an either-or proposition; it’s a continuum,” said Dr. Sally A. Mackenzie, the Ralph and Alice Raikes Professor in the department of agronomy and horticulture in biological sciences at the University of Nebraska—Lincoln. “We’re not able to predict what biotechnology will give us. It’s a tool in an increasingly robust toolbox.”

Genetic modification

Dr. Mackenzie says that genetic modification simply refers to human intervention to create a different genetic combination to create a desired outcome.

“We’re using transgenes to create gene combinations that result in diversity and enhanced performance. The outcomes rely on the genes themselves and how they are expressed within the plants.” This same concept is being used in animal research and in human health research for cancer and other diseases
Researchers are focused on helping plants overcome stresses, challenges and inhibitors that keep them from achieving their full genetic potential. Epigenetics is one emerging technology that involves temporarily adding a transgene to a plant and then removing it—while leaving the effects of that transgene intact within the plant. This can lead to more vigorous plants, more biomass and more production.

“With epigenetics, what you eat is not transgenic, but transgene technologies were used to affect the performance of the plant,” Dr. Mackenzie said.

“There has not been a single documented case of a food allergy or human health situation due to crop biotechnology.”

Researchers are also looking at the microbes the plants live with, which dramatically impact the way a plant uses water and nitrogen, and interacts with pathogens. This approach doesn’t change the genetic complexion of the plant, but instead strives to better understand and manage the environment around the plant to optimize its performance.

“GM foods unsafe” is a scare tactic.

 Corn field and center pivot irrigation in south central Nebraska. July, 2010. Photo by Craig Chandler / University CommunicationsDr. Mackenzie says that assertions that GM foods are unsafe is a distortion of the truth— and in many cases, is a scare tactic used by special interest groups to gain financial support and media attention. “There has not been a single documented case of a food allergy or human health situation due to crop biotechnology,” Dr. Mackenzie added. “It has never been unsafe or unhealthful. When we see distortions of the truth, the first place we should look is at who is benefitting from this misinformation.”

When asked about concerns about insects and weeds becoming resistant to GM crops, she asserts that this concern cannot be placed at the doorstep of biotechnology.

“There is nothing about GM technology that causes weeds to become tolerant to herbicides, just as there is nothing inherent in our medical system that makes us more resistant to antibiotics,” she said. “Just as any doctor needs to be responsible in prescribing medications, farmers need to be careful stewards of their crops—regardless if they are growing GM or non-GM varieties.”

Dr. Mackenzie said that genetics have long been part of agriculture. For example, the original corn was much like birdseed—and the alkaloid levels in the original tomato would be fatal to humans. Ruby red grapefruit is sweeter because gamma radiation was used to mutate the genes to express themselves in that manner.

This is what feeds us.

“Carrots, wheat, corn—Mother Nature never meant for us to eat any of them. Plants resist being eaten,” Dr. Mackenzie said. “All the crops we eat are essentially manmade through conventional breeding. This is what feeds us. Today we’re more precise and we can better manage change thanks to advancements in knowledge and technology.”

“Transgene plants will be part of our future; they must be, “ Dr. Mackenzie said. “Our problems are so challenging, so daunting that we don’t have the luxury to depend on alternatives that are less sustainable or less productive.

“If we’re going to meet global food demand over the next 30 years, we need to pull out all the stops. This is our generation’s equivalent of the putting a man on the moon.”

View Dr. Mackenzie’s presentation as part of the UNL Heuermann Lecture Series.

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