Expression analysis of genes involved in terpenes biosynthesis in black cumin (Nigella sativa) plants treated with methyl jasmonate

Black cumin (Nigella sativa) is an important medicinal plant belongs to the Ranunculaceae which produce large diversity of secondary metabolites including industrial and medicinal monoterpenes/ triterpenes. In the present work, relative gene expression of genes involved in biosynthetic pathway of terpenes including a monoterpene synthase (MTS), geranyldiphosphate synthase (GDS), β- amyrin synthase (βAS) and squaleneepoxidase(SQE) were investigated in black cumin plants treated with methyl jasmonate. The plants were grown in a greenhouse sprayed with 0.1 mM methyl jasmonate. Samples were collected at 0, 4, 8, 24, 48 and 72 hours after applying the treatments. RT-PCR was performed by gene-specific primers after RNA extraction and cDNA synthesis. Results of semi quantitative RT-PCR showed that the expression pattern of GDS gene differed with the results of other genes. The highest gene expression of GDS was observed at 4 h and its expression remained at the same level till 8 h then dropped at next time periods. The expression patterns of monoterpene synthase, β-amyrin synthase and squaleneepoxidase showed rising trend. Gene expression analysis of the genes at transcript level using semi-quantitative PCR in black cumin leaves treated by methyl jasmonate revealedinduced-geneexpression which might show the roles of terpenes in defense mechanisms and signal transduction. Consequently, methyl jasmonate treatment can be considered to induce the terpene biosynthetic pathway and to study the enzymes/ metabolites associated with terpenoid metabolism.