The Expression enhancement of some genes involved in th diosgenin biosynthesis pathway in fenugreek treated with different levels of melatonin under salinity stress

Diosgenin is one of the most important medicinal compounds in the world; however, little information is available on the biosynthetic pathway of this valuable metabolite in fenugreek. Given the importance of increasing the production of diosgenin, the application of various stimulants to enhance its production might be an interesting research topic. The aim of this study was to increase the expression of some genes involved in the biosynthesis pathway of diosgenin in fenugreek plants treated with salinity stress and different levels of melatonin. Treatments in this experiment included different salinity levels (0, 150 and 300 mM), different levels of melatonin (0, 30, 60 and 90 ppm) and a combination of different levels of salinity and melatonin. The expression of Cycloartenol synthase، 26-o-Beta glucosidase ,C4-demethylase in 150 mM and 60 ppm melatonin salinity treatments increased 7, 5 and 4 times compared to the control treatment (no melatonin application and salinity stress), respectively. The expression of C22-hydroxylase and Δ7-reductase genes was less affected by all experimental treatments. Overall, the results of the present study showed that the application of melatonin in fenugreek under salinity stress substantially increases the expression of genes involved in the biosynthesis pathway of diosgenin as a suitable functional stimulus.  The results of this research could be used in the pathway engineering of this valuable medicinal metabolite.