Isolation, characterization and functional analysis of eugenol O-methyl transferase (EMOTs) gene promoter, as a responsive gene to drought stress, from Ocimum basilicum L.

Ocimum basilicum L. (2n=48) is a medicinal plant that belongs to Lamiaceae family. Eugenol is one of the most important compounds of basil essential oil which is applied against bacteria, fungi and nematodes in various industries. Phenylpropanoids such as methyl eugenol possess anti-oxidant properties against free radicals and act as protective compounds in plant responses to biotic and abiotic stresses. Methyl eugenol O-methyl transferase (EOMTs), as a key enzyme of phenylpropanoids biosynthesis pathway, converts eugenol into methyl eugenol by methylation. In this study, we isolated, characterized and function analyzed the EOMTs gene promoter from basil plant with the aim of investigating the gene expression regulation of this gene under different environmental conditions and recognition its regulatory motifs. Analysis of EOMTs gene promoter indicated that this sequence was included some important regulatory elements which responded to high temperature and drought stress such as MYB, MYC, HSE, and WRKY. It is expected that this gene indicates expression changes under biotic and abiotic stresses because there are stress-responsive regulatory sites in ObEOMTs gene promoter. Function verification of ObEMOTs promoter in Nicotiana tabacum leaves showed that this promoter including core elements is able to direct the expression of GUS gene.