Location: Crop Protection and Management ResearchTitle: Aflatoxin production and environmental oxidative stress in Aspergillus flavus: Implications forhost resistance Author
|Fountain, Jake - University Of Georgia|
|Yang, Liming - University Of Georgia|
|Khera, Pawan - University Of Georgia|
|Nayak, Spurthi - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India|
|Kemerait, Robert - University Of Georgia|
|Lee, R - University Of Georgia|
|Varshney, Rajeev - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India|
Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2015
Publication Date: 7/10/2015
Citation: Fountain, J.C., Yang, L., Khera, P., Nayak, S.N., Kemerait, R.C., Lee, R.D., Scully, B.T., Varshney, R.K., Guo, B. 2015. Aflatoxin production and environmental oxidative stress in Aspergillus flavus: Implications forhost resistance. Meeting Abstract. American Phytopathological Society Annual Meeting, Sugust 1-5, 2015, Pasadena, California.
Technical Abstract: The contamination of maize kernel tissues with aflatoxin is of major concern in global food production, particularly in developing countries. Resistance to aflatoxin is negatively influenced by environmental stress, namely drought stress. Given that reactive oxygen species (ROS) are known to accumulate in host tissues during abiotic stress, and have been demonstrated to exacerbate aflatoxin production in Aspergillus spp. in vitro, it has been hypothesized that ROS may serve as a signaling molecule in cross-kingdom communication between maize and A. flavus. If stimulated by ROS, aflatoxin production may function to affect oxidative stress tolerance in A. flavus. In order to determine the potential functions of aflatoxin production in oxidative responses, we compared the responses of toxigenic and atoxigenic isolates of A. flavus to H2O2 induced oxidative stress. It was found that there is a great deal of variability among isolates with regard to their degree of oxidative stress tolerance with toxigenic isolates generally exhibiting greater levels of tolerance. To explain the functional differences between these isolates, we also performed transcriptomic and enzymatic activity analyses examining the oxidative responses of the isolates with respect to their ability to produce aflatoxin. In application, identifying the causes of variation in oxidative stress tolerance among atoxigenic isolates may allow for prediction of their performance as biocontrols in field applications.