Characterization of Expressed Genes Under Ozone Stress in Soybean

To identify the genes specifically or predominantly expressed in ozone-fumigated leaves of two soybean cultivars: Jinpumkong and Cheongjakong, expression levels of mRNA were investigated using differential banding patterns on agarose gel. A total of 408 bands differently expressed after ozone fumigation was identified; 153 of which were up-regulated while 225 were down-regulated. Using BLASTx, the putative functions of the expressed sequence tags were determined. The 178 ozone-regulated differentially expressed genes (DEGs) matched with the previously known genes with high significance. The putative functional classes of these DEGs were categorized by two databases: Gene Ontology and MIPS. Based on the Gene Ontology database, majority of the DEGS have molecular function related to transferase activity. Most of them are involved in the cellular and metabolic processes. Cytoplasmic part and cell part were the primary types of cellular component in the ozone-responding DEGs. Whereas findings using the MIPS database revealed the function distribution of up-regulated DEGs across all classes. Most of the ozone-regulated genes identified in this study are related to biotic and abiotic stresses. The characterized ESTs will serve as useful data to provide a better understanding of the molecular basis and transcript profiles.