Effect of weeds on corn

Microarray analysis was used to identify changes in gene expression in maize leaves collected from plants at the 11-14 leaf stage that resulted from competition with velvetleaf. Genes involved in carbon and nitrogen utilization, photosynthesis, growth and development, oxidative stress, signal transduction, responses to auxin and ethylene, and zinc transport are repressed in maize growing in competition with velvetleaf. Very few genes are induced due to competition with velvetleaf, and those that are provide little indication of the physiological response of maize. No significant differences were observed in multiple genes responsive to water stress or sequestering/transporting most micronutrients indicating that these stresses are not a major component of velvetleaf competition with maize at the developmental stage tested. Keywords: Stress response (weed competition) Maize plants were grown in 8 separate plots. Four of the plots were seeded with velvetleaf (1W-4W) and four were hand cultivated periodically to remove most weeds throughout the growing season (1-4). Samples of leaf material was collected from four plants in each plot and pooled. A balanced labeling comparison (R vs B) of weedy verses control was done with 10 independent hybridizations. Thus, experiment 1R4WB represents the comparison of control sample 1 labeled with Cy3 (R) to weedy sample 4 labeled with Cy5(B).