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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #313098

Title: Aflatoxin production and oxidative stress in Aspergillus flavus

item FOUNTAIN, JAKE - University Of Georgia
item YANG, LIMING - University Of Georgia
item KHERA, PAWAN - University Of Georgia
item KEMERAIT, ROBERT - University Of Georgia
item LEE, R - University Of Georgia
item Scully, Brian
item BARSHNEY, RAJEEV - International Crops Research Institute For Semi-Arid Tropics (ICRISAT) - India
item Guo, Baozhu

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/29/2014
Publication Date: 2/1/2015
Citation: Fountain, J.C., Yang, L., Khera, P., Kemerait, R.C., Lee, R.D., Scully, B.T., Barshney, R.K., Guo, B. 2015. Aflatoxin production and oxidative stress in Aspergillus flavus. Meeting Abstract. Souther Division Annual Meeting, American Phytopathology Society, February 1-3, 2015, Atlanta, Georgia.

Interpretive Summary:

Technical Abstract: The colonization of crops by Aspergillus flavus results in the production of aflatoxins. Aflatoxin production is also exacerbated by abiotic stresses in the field. Here, we investigated the role of reactive oxygen species (ROS), which accumulate in plant tissues in response to drought and heat stress, and aflatoxin production in different isolates of A. flavus and A. parasiticus. Ten isolates were used, including nine A. flavus toxigenic (+) and atoxigenic (-) isolates: NRRL3357(+), A9(+), AF13(+), Tox4(+), A1(-), K49(-), K54(-), AF36(-), and Aflaguard(-), and one A. parasiticus isolate, NRRL2999(+). The isolates were cultured in toxin-conducive yeast extract-sucrose (YES) media supplemented with hydrogen peroxide (H2O2) with a concentration gradient from 0 to 45mM in 5mM increments for 7 days at 32°C. The different isolates responded to the H2O2 gradient differently in terms of biomass and survivability. Aflatoxin production was also found to be enhanced by increasing [H2O2]. However, growth in the toxin-inconducive media, yeast extract-peptone (YEP), all isolates survived at a higher [H2O2]. Therefore, additional studies will seek to understand why different isolates behave differently in YES and YEP media in response to H2O2 stress in order to examine the potential functional roles of aflatoxin production and ROS in Aspergillus spp. The activity levels of antioxidant enzymes and the expression of stress responsive genes will also be examined