Breakthrough In Aflatoxin Suppression

Aflatoxins, which can infect peanuts, corn and other crops, are a major health risk worldwide.

Aworldwide group of plant scientists have made a significant research breakthrough by suppressing the fungus that produces aflatoxin in peanuts.

Zhi-Yuan Chen, a researcher in the LSU AgCenter Department of Plant Pathology and Crop Physiology, is one of the collaborators in the project headed by scientists at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) in Hyderabad, India. Other participating institutions are the Donald Danforth Plant Science Center in St. Louis, Missouri, and the United States Department of Agriculture.

Aflatoxins are a major health risk worldwide, and infected crops are not suitable for human consumption. Along with peanuts, aflatoxin infects corn, cottonseed, tree nuts and chilies.

Zhi-Yuan Chen, a researcher in the LSU AgCenter Department of Plant Pathology and Crop Physiology, explains the apparatus he uses in his lab to analyze aflatoxin resistance in corn seeds.

Genetic Resistance
In his work in the AgCenter, Chen has developed a method of changing the genetics of corn plants to impart resistance to Aspergillus flavus, the fungus that causes aflatoxin. He has produced a vector carrying the partial sequences of genes from A. flavus for inserting into plants susceptible to the fungus, such as corn.

Through collaboration with scientists at Iowa State University, the genetic material from the pathogen was inserted into the corn in such a way that the plant sees it as invasive and triggers a defense response to generate resistance, Chen says.

The program at the ICRISAT is led by Pooja Bhatnagar-Mathur, who had collaborated previously with Chen on a peanut proteomics project and learned about Chen’s novel “pre-immune” disease control strategy during one of her visits to LSU.

A. flavus ‘Vaccination’
The research team at ICRISAT used the same vectors designed and constructed by Chen’s team for corn to introduce into peanuts genetic material that causes the peanut plant to recognize the A. flavus infection and institute a defense against it.

It’s like a vaccination. “When a portion of the gene sequence is introduced into the plant, the plant recognizes and attacks the pathogen after ‘seeing’ the sequence. It binds to the pathogen like an antibody so the pathogen doesn’t increase,” Chen says.

“The construct was developed here for corn, then moved to peanuts,” he says of the five-year collaboration to evaluate peanut lines. The transgenic corn plants carrying the same genes have gone through several years of isolated field evaluation at LSU AgCenter under strict governmental regulations for changes in aflatoxin resistance.

Because of tight restrictions in working with transgenic materials, field evaluation of the new corn lines takes longer to complete in the United States, Chen says.

Chen’s work with corn is continuing, and he hopes to publish the study in the coming year.


Information provided by LSU AgCenter.

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