This small molecule could have a big future in global food security

Researchers at the University of Arizona have found a promising way to prevent the loss of millions of tons of crops to a fungus each year, offering the potential to dramatically improve food security, especially in developing countries. 

The team's approach uses transgenic corn plants that produce small RNA molecules that prevent fungi from producing aflatoxin, highly toxic substances that can render an entire harvest unsafe for human consumption even in small amounts.

Although extensive field testing will have to precede widespread application of the new technique in agricultural settings around the world, the results of the study, published in Science Advances, showed that transgenic corn plants infected with the fungus suppressed toxin levels below detectable limits.

Crops all over the world are susceptive to infection by fungi of various Aspergillus species, a fungus that produces secondary metabolites known as aflatoxins. These compounds have been implicated in stunting children's growth, increasing the risk for liver cancer, and making people more susceptible to diseases such as HIV and malaria.

Funded by the Bill and Melinda Gates Foundation, study leader Monica Schmidt and her team set out to study whether a naturally occurring biological mechanism called RNA interference could be used as a weapon against the Aspergillus toxin. That approach, called Host-Induced Gene Silencing, or HIGS, builds on previous work by other researchers who discovered that during the infectious process, the host plant and the fungus exchange small nucleic acid molecules.