|ZABLOTOWICZ, ROBERT - Retired ARS Employee|
|SHIER, W - University Of Minnesota|
|JOHNSON, BOBBIE - Retired ARS Employee|
|PHILLIPS, NICHOLAS - Waters Corporation|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/14/2015
Publication Date: 9/1/2015
Citation: Abbas, H.K., Zablotowicz, R.M., Shier, W.T., Johnson, B.J., Phillips, N., Weaver, M.A., Abel, C.A., Bruns, H.A. 2015. Aflatoxin and Fumonisin in corn (Zea mays) infected by common smut Ustilago maydis. Plant Disease. 99(9):1236-1240.
Interpretive Summary: Mycotoxins (such as aflatoxins and fumonisin) a toxic chemical compounds produce by fungi (molds) when present as contaminants in food products can affect humans and animals. Common smut galls are also caused by fungi on corn and is used as a food source in some cultures. It is also a common naturally infected disease in corn in the USA. We tested corn infested with common smut for aflatoxin and fumonisin and found dangerous levels (above the USDA limit) of these chemicals. Farmers can use the visible smut to determine if their crops may be prone to be infested with mycotoxins. The farmers can avoid harvesting their crops heavily infested fields to avoid the cost of marketing. This information will be useful to corn farmers and the food industry and scientist inside and outside the ARS.
Technical Abstract: Corn infected with Ustilago maydis (common smut) produces galls that are valued food in certain cultures, but may be contaminated with mycotoxins. Field studies conducted in Elizabeth, Mississippi used near isogenic Bt and non-Bt corn hybrids. The levels of aflatoxin and fumonisin were determined in kernels from ears having common smut galls and kernels from ears free of visible symptoms. Mycotoxins were also determined in excised smut galls in 2007, 2008, and 2009. In 2006 a high degree of common smut was observed (~ 17 % infected ears) with lower incidences in 2007, 2008 and 2009 (2.6 to 4.8 %), with no effect of the Bt genotype. Grain from smut-infected corn contained from 1035 to 4485 µg kg-1 total aflatoxin compared to 4 to 100 µg kg-1 in non-infected corn. However, aflatoxin content in smut galls was similar to aflatoxin levels in non-infected grain. Likewise, fumonisin levels were from 49 to 203 mg kg-1 and 4 to 32 mg kg-1 in smut-infected and non-infected grain, with 12 to 135 mg kg-1 found in galls. These studies indicate that high levels of mycotoxins can be associated with smut-infected corn and potential toxicological implications of high levels of fumonisin should be considered when cultivating corn smut as a food product.