Abstract
Recently, peptides encoded by short open reading frames (sORFs) are reported to play roles in various functions in many organisms. To investigate function of sORFs in plants, we identified sORFs ranging from 90 to 300 bp in the intergenic regions of Arabidopsis and rice. We developed custom microarrays including sORFs and annotated genes in Arabidopsis and rice to analyze gene expression profile. Microarray analysis was carried out in various tissue types. The expression of sORFs could be detected in various plant tissues. Full length cDNA of sORF was verified by RACE experiment. Next, promoter region and sORF without stop codon was fused to GUS gene and then expressed it in Arabidopsis. GUS signal was detected in transgenic plants, indicating that sORF was actually translated in plants. We selected sORFs based on expression, conservation, peptide hormone-like sequence to generate sORF overexpression Arabidopsis and rice plants. Some overexpression plants showed visible phenotypes. Thus, we conclude that sORFs have roles in growth and developmental processes.
