ARS | Publication request: Gene Expression Profiles in Developing Corn Kernels in Response to Drought Stress

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 27, 2009
Publication Date: October 27, 2009
Citation: Guo, B. Wang, Z. Luo, M. Lee, D. Scully, B.T. Gene Expression Profiles in Developing Corn Kernels in Response to Drough Stress. Presented at the Mississippi State University of Reducing Aflatoxin Contamination in Corn meeting on October 27-28, 2010.

Technical Abstract: Preharvest aflatoxin contamination of corn is aggravated by abiotic stress and the hot and humid weather patterns along with suboptimal summer rainfall favor the development. Drought stress is a major factor known to contribute to preharvest aflatoxin contamination. The gene expression studies were conducted in the field rain-out cages with irrigation system. Drought stress was imposed at 20 days after pollination (DAP). Immature ears were sampled at the 25, 30, 35, 40, 45 DAP under drought stress verse well-watered condition using the 70-mer maize oligonucleotide microarrays. Gene expression analyses were also conducted using oligonucleotide macroarray to evaluate corn germplasm of preharvest developing kernels. Mature ears were harvested and tested in the laboratory for resistance to fungal colonization. The data suggest that preharvest drought stress could affect on postharvest contamination in different genotypes. These results indicate that 35 to 45 DAP was a unique time-point when the developing kernels entered a distinct phase related to aflatoxin contamination. The difference in aflatoxin contamination in preharvest kernels among resistant and susceptible lines not only depends on genetics of the inbred, but also on the response of drought stress and defense related genes.