DIFFERENTIAL EXPRESSION OF SINAT5 GENE IN GROWTH STAGES OF Zea mays

Proteolytic pathways of post translational protein modification and regulation by 26S proteosomes play key roles in plants developmental processes. One of the main pathways of post-translational regulation of the levels of specific proteins in eukaryotic cells is based on ubiquitination process in which E3 ligases such as SINAT5 (Seven in Absentia in Arabidopsis thaliana 5) transfer the ubiquitin to the target proteins. SINAT5 has been known to regulate auxin signaling and root morphogenesis by ubiquitination of NAC1 protein. For further identification, the expression and the relative level of maize SINAT5 transcript were analyzed using the basic and real-time PCR with template leaf materials separately collected from the vegetative and the flowering stages of maize plants grown under the normal growth conditions. The obtained results not only confirmed the presence of SINAT5 transcript in the leaf tissues of both growth stages but also revealed its high level of expression in the leaf samples of flowering stage. This may address the large numbers of protein targets for ubiquitination at flowering stage in compare to vegetative stage.