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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #323234

Research Project: Developing Genomic Approaches to Improve Resistance to Diseases and Aflatoxin Contamination in Peanut and Corn

Location: Crop Protection and Management Research

Title: Mitigation of aflatoxin contamination in maize kernels is related to the metabolic alternation of reactive oxygen and nitrogen species by relative humidity

Author
item Yang, Liming - University Of Georgia
item Fountain, Jake - University Of Georgia
item Chu, Ye - University Of Georgia
item Ni, Xinzhi
item Kemerait, Robert - University Of Georgia
item Lee, Robert - University Of Georgia
item Guo, Baozhu

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/29/2015
Publication Date: 10/29/2015
Citation: Yang, L., Fountain, J., Chu, Y., Ni, X., Kemerait, R.C., Lee, R.D., Guo, B. 2015. Mitigation of aflatoxin contamination in maize kernels is related to the metabolic alternation of reactive oxygen and nitrogen species by relative humidity [abstract]. UGA Plant Center Retreat Meeting.

Interpretive Summary:

Technical Abstract: Environmental factors have been shown to be linked to exacerbated infection of maize kernels by Aspergillus flavus and subsequent aflatoxin contamination. Kernel resistance to aflatoxin contamination is associated with kernel water content and relative humidity during in vitro assays examining aflatoxin production in various hybrids. However, the physiological and biochemical basis of humidity’s influence on resistance is not understood. In this study, kernels of the resistant inbred Lo964, the susceptible inbred B73, and their F1 hybrid were incubated in a humid environment with and without 3-day pre-incubation at high humidity prior to inoculation with A. flavus NRRL3357. Subsamples of kernels were taken over a 7 day period and were examined for aflatoxin content, accumulation of reactive oxygen and nitrogen species, and the activities of their respective scavenging enzymes. Pre-incubation resulted in increased sporulation visible on kernel surfaces, but juristically decreased the levels of aflatoxin in the kernels of all the lines. In pre-incubated kernels, superoxide radical, hydrogen peroxide, and nitric oxide contents increased at 2-3 day after inoculation (DAI), compared to those of kernels that were not pre-incubated which showed steep increases after 3-4 days of inoculation. Moreover, B73 and the F1 hybrid showed a higher ROS and NO contents than Lo964. Taken together, these findings suggest that ROS and RNS participate in the response of kernels to A. flavus infection and aflatoxin production with resistant and susceptible lines exhibiting different responses.