COLLEGE STATION — Aflatoxin research at Texas A&M University is showing promise in solving this age-old problem.
A biotechnological approach may be the answer that researchers have been looking for, according to Dr. Nancy Keller, plant pathologist with the Texas Agricultural Experiment Station.
Aflatoxin is a fungus that infects corn, cotton, peanuts and other crops. About a third of the Texas corn crop was lost to it last year, Keller said.
Texas A&M researchers have identified the genes in the fungus that are responsible for making aflatoxin. The next step is locating the genes that turn the fungus off, Keller said.
“We’ll now be able to clone the aflatoxin genes in the fungus itself and ask, ‘How do these genes turn on and off?’ By understanding how they turn on and off, we should be able to develop a rational control strategy to permanently keep them off,” she said. She’s already found a gene in soybeans that represses aflatoxin in lab studies. “Everyone’s always known that, for some reason, soybeans are pretty resistant to aflatoxin,” she said.
Now she’ll take that gene and breed into aflatoxin-susceptible plants.
“That takes some time itself in transforming these crops, but it’s an eventuality and we’ve had success, so we’ll know it will work,” Keller said.
If eaten in large doses, aflatoxin can cause liver cancer in humans and animals.
For the past 30 years, control strategies for the fungus have included finding resistant lines of corn and crops while also changing cultural practices such as irrigation.
“We know that aflatoxin is associated with drought and stress, so it’s a very warm-loving fungus,” she said.
If there is too much aflatoxin found in a crop in the United States, it is either destroyed or it is detoxified with ammonia. “That’s a big economic loss to the producer.
“If an animal should get it, then of course, you’d have the losses due to sickness and/or death,” Keller.
In developing countries, it’s a greater problem because they don’t have the means to destroy the crops that have it. There is strong evidence that aflatoxin is the leading cause of liver cancer in Africa and China.
Additionally, aflatoxin is a trade barrier as well. “It’s the only micro-toxin in the world on which every country has levied international sanctions,” she said.