Submitted to: Maize Genetics Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2007
Publication Date: 3/20/2007
Citation: Guo, B., Luo, M., Liu, J., Lee, R.D. 2007. Gene expression profiles of corn developing kernels of Tex6 using maize oligo-microarray [abstract]. In: Proceedings of the 49th Annual Maize Genetics Conference, March 22-25, 2007, Pheasant Run, St. Charles, IL. p. 36. Interpretive Summary:
Technical Abstract: Maize oligonuleotide microarray was used to analyze the temporal patterns of gene expression in late developmental maize kernels of Tex6 after 25 days after pollination (DAP). There was a total of 57,452 70-mer oligonucleotides on a set of two array-slides. Because of the resistant traits of Tex6, we reasoned that this unique maize line would be an interesting candidate for microarray study of gene expression in developing kernels during the time favorable for aflatoxin contamination. In this report, transcriptional profiles of Tex6 kernels at 25, 30, 35, 40, and 45 DAP were compared using the 70-mer maize oligonucleotide arrays based on relative expression quantitation, in which glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was used as an internal control. Quatitative real-time PCR was also used for validation of selected genes from microarray data. There was a total of 8621 positive array spots with unique IDs and 4247 cross-talking genes identified in all sampling stages. These were averaged at 6218 array spots expressed in each sampling stage. Expression patterns of key genes in several metabolic pathways, including starch, lipid and storage proteins, were analyzed. Among the storage proteins, the expression patterns of defense related genes (2676 unique IDs) were identified as up-regulated, down-regulated, or no-change based on hierarchical analysis. Some defense related genes were highly expressed throughout the late kernel development. Twenty genes with different expression trends from microarray were selected for validation using quantitative real-time PCR. The real-time PCR reproduced the expression patterns of up- and down-regulated genes, but did not completely reproduce the genes without changes as in the microarray study. This study was able to investigate the gene categories at various stages of kernel development, therefore providing further insight into gene expression profiles associated with the reduced aflatoxin contamination of Tex6.