Relative expression analysis of the monoterpene biosynthesis genes in Lavender (Lavandula angustifolia) in response to salicylic acid and methyl jasmonate

Important monoterpenes such as camphor and fenchol are components of lavender (Lavandula angustifolia) essential oil. Monoterpene synthases are suitable target genes for metabolic engineering in Lavender. This study was performed to analyze the expression and induction of the two key genes (borneol synthase and fenchol synthase) involved in monoterpenes biosynthetic pathway in lavender after elicitation by methyl jasmonate and salicylic acid. First, plants in the pre-flowering and post-flowering stages were treated separately by methyl jasmonate and salicylic acid, each at a concentration of 1 mM. Then, plant leaves were harvested 0 (control), 24, 48 and 72 hours after treatments for gene expression analysis. The results showed that the expression of these genes was affected by salicylic acid and methyl jasmonate treatment. In general, the expression of both genes in the pre-flowering stage was higher than that of post-flowering. Moreover, the expression of borneol synthase was more affected by methyl jasmonate, so that its expression trend was completely increased up to 72 hours. Given the increased expression of borneol synthase and fenchol synthase in plants treated with salicylic acid, and methyl jasmonate it could be expected that the content of valuable monoterpenes such as camphor and fenchol increase in lavender.