|YANG, LIMING - University Of Georgia|
|FOUNTAIN, JAKE - University Of Georgia|
|CHU, YE - University Of Georgia|
|LEE, ROBERT - University Of Georgia|
|KEMERAIT, ROBERT - University Of Georgia|
Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 2/20/2016
Publication Date: 3/15/2016
Citation: Yang, L., Fountain, J.C., Chu, Y., Ni, X., Lee, R.D., Kemerait, R.C., Guo, B. 2016. Differential accumulation of reactive oxygen and nitrogen species in maize lines with contrasting drought tolerance and aflatoxin resistance [abstract]. American Phytopathological Society Abstracts.
Technical Abstract: Abiotic stresses such as drought stress can exacerbate aflatoxin contamination of maize kernels. Previous studies showed that maize lines resistance to aflatoxin contamination tend to exhibit enhanced drought tolerance and accumulate lower levels of reactive oxygen species (ROS) and nitrogen species (RNS) than those that are susceptible to both in leaves. In order to investigate whether ROS or RNS accumulation in kernel tissues along with relative humidity may potentially influence aflatoxin production, we performed an in vitro kernel screening assay to examine the accumulation of ROS and RNS over time in resistant (Lo964) and susceptible (B73 and F1 of Lo964 x B73) lines with and without a 3 day pre-incubation in a 100% humidity environment. In the assay, kernels, with and without pre-incubation, were inoculated with A. flavus and examined daily for 7 days for ROS, RNS, and aflatoxin accumulation. Pre-incubation resulted in enhanced visible conidiation, however dramatically reduced aflatoxin production. Pre-incubation also resulted in increases in ROS and RNS levels at 2-3 days post inoculation while kernels without pre-incubation saw increases at 3-4 days after inoculation. In addition, Lo964 exhibited lower overall accumulation of ROS and RNS than B73 or the hybrid. This indicates that peaks in oxidative and nitrosative stress compounds later in infection and the accumulation of higher levels of said compounds are correlated with exacerbated aflatoxin production.