A host of human and livestock diseases may be the result of cellular suicide, triggered by fungus-produced toxins in corn, tomatoes and other crops, according to a UC Davis plant disease expert. In laboratory experiments, plant pathologist David Gilchrist found that two chemically similar fungal toxins that naturally occur in infected crop plants caused animal cells to self-destruct. This specific process of gene-controlled cell death, known as "apoptosis," normally helps regulate development in plants and animals. It is marked by certain abnormal changes in the DNA of the cell's nucleus, leading up to the cell's death. One of the toxins studied has concerned health and agricultural policy-makers because corn contaminated with the toxin has been linked to serious diseases, including esophageal cancer in humans and a deadly brain disease in horses. "This initiation of apoptosis by these fungal toxins, which are widespread in food crops and animal feed, identifies a previously unrecognized mechanisms underlying health risks for humans and livestock," says Gilchrist. The research team published these findings this month in the scientific journal the Proceedings of the National Academy of Sciences.