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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #316701

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

Location: Crop Protection and Management Research

Title: Dissecting the various responsive modes to drought stress responses in corn with contrasting tolerance to drought

item Yang, Liming - University Of Georgia
item Fountain, Jake - University Of Georgia
item Jiang, Tingbo - Northeast Forestry University
item Lee, R - University Of Georgia
item Kemerait, Robert - University Of Georgia
item Scully, Brian
item Chen, Sixue - University Of Florida
item Guo, Baozhu

Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2015
Publication Date: 7/10/2015
Citation: Yang, L., Fountain, J.C., Jiang, T., Lee, R.D., Kemerait, R., Scully, B.T., Chen, S., Guo, B. 2015. Dissecting the various responsive modes to drought stress responses in corn with contrasting tolerance to drought. Meeting Abstract. American Phytopathological Society. American Phytopathological Society (APS), August 1-5, 2015, Pasdena, California.

Interpretive Summary:

Technical Abstract: Drought decreases crop yield and exacerbates Aspergillus flavus infection resulting in pre-harvest aflatoxin contamination. Deciphering crop tolerance and adaptation to drought can contribute to the improvement of drought tolerance through breeding. In order to investigate the responsive modes in corn to drought stress, corn inbred lines with contrasting drought sensitivities were used and the treatments were water stressed or deficit and well-watered control at different vegetative and reproductive stages. Comparative proteomics revealed that the sensitive line exhibited a vigorous induced response to stress, while the tolerant line displayed stable, constitutive expression of defense proteins. Bioinformatics analysis illustrated that drought-responsive proteins in developing kernels were different at diverse biological processes, mainly including hormone regulation and redox homeostasis. Further physiological and biochemical assays found that drought-sensitive lines presented a sharp rise of ABA and IAA contents quickly after stress induced and then a significant decrease as the drought prolong in contrast to the well-watered control. However, the contents of ABA and IAA displayed a progressive stable increase profiles for tolerant lines in responding to continued drought induction. Moreover, the sensitive lines was found to accumulate much more reactive oxygen species (ROS) and nitric oxide, and to rapid increase in enzyme activities involved in ROS and reactive nitrogen species(RNS) metabolism, in comparison to the tolerant lines. The observed antioxidant enzyme activities of superoxide dismutase and catalase were constitutively higher in the tolerant lines than that in the sensitive lines, which showed a rapid induction of activity following drought induction. These results suggests that drought sensitivity was associated with different and diverse metabolic pathways in corn, and the tolerant lines may be able to better sequester excessive accumulation of harmful metabolites, like ROS and RNS, than sensitive lines.