ABSTRACT
Plant ODC (ornithine decarboxylase) plays a vital role in normalizing cell division in actively growing tissues. The ODC is a key precursor enzyme for nicotine and nornicotine biosynthesis in plants. ODCs are widely present in many plant families but have not been functionally validated and characterized at the molecular level. In the present study, 58 plant ODCs were identified and were found to contain two putative regulatory motifs, specifically PLP (Pyridoxal 5'-phosphate) and Orn/DAP/Arg decarboxylase family 2 pyridoxal-phosphate, that are highly conserved among diverse plant species. Further, the cis-regulatory elements and interacting partners of the gene revealed the importance of ODC in various metabolic pathways. The qRT-PCR revealed highest relative expression of ODC in floral meristem and roots. Our results suggest that ODC can be effectively used as an ideal candidate for engineering polyamine biosynthesis and would be crucial for developing ultra-low nicotine content tobacco lines via genome editing.