|YANG, LIMING - University Of Georgia|
|FOUNTAIN, JAKE - University Of Georgia|
|JI, PINGSHENG - University Of Georgia|
|LEE, ROBERT - University Of Georgia|
|KEMERAIT, ROBERT - University Of Georgia|
Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/27/2014
Publication Date: 1/10/2015
Citation: Yang, L., Fountain, J., Ni, X., Ji, P., Lee, R.D., Scully, B.T., Kemerait, R.C., Guo, B. 2015. Maize sensitivity to drought stress is associated with differential responses to reactive oxygen species. Meeting Abstract. Plant and Animal Genome Conference. Plant and Animal Genome Conference, January 11-15, 2015, San Diego, California.
Technical Abstract: Aflatoxin contamination of crops is exacerbated by preharvest drought stress. Previously, we identified maize drought responsive proteins in lines with differing drought sensitivities, and proposed a model for drought responses. The sensitive line, B73, exhibited a vigorous induced response to stress while the tolerant line, Lo964, exhibited stable, constitutive expression of defense proteins. In order to verify the proposed model, we examined the metabolic responses of tolerant (A638, Grace E-5, Va35, Lo964), and susceptible (B73 and Lo1016) maize lines to drought stress focusing on reactive oxygen species (ROS) metabolism including catalase and superoxide dismutase activity. The lines were cultivated in the greenhouse with controlled irrigation for 30 days (V3-V4 stage). Drought was then induced by withholding water for 9 days followed by a recovery period of normal irrigation for 3 days. Leaf and root tissue samples were collected every 3 days for both drought and normally irrigated samples. Overall, the observed enzyme activities were constitutively higher in tolerant lines than in susceptible ones which showed a rapid induction following drought induction. Lo964 tissues were also found to accumulate less ROS than B73. This is in agreement with the proposed model, and suggests that tolerant lines may be able to better sequester ROS than susceptible lines. Continuing studies will examine this in additional lines and explore the roles of additional metabolites.