Expression of CYP genes involved in sesamin biosynthesis pathway in different varieties of sesame seeds (Sesamum indicum L.)

Sesame (Sesamum indicum L.) is one of the oldest oilseed crops that has been a main food source providing beneficial nutritional outcomes to human health due to its high contents of antioxidants and secondary metabolites. The importance of sesame arises from presence of antioxidant sesamin. Over recent decades, due to being used in cancer cases, there have been numerous efforts aimed at better understanding of the genes underlying sesamin biosynthesis and increasing their expression. In this research, expression levels of the key genes in sesamin biosynthesis pathway including CYP81Q1, CYP81Q2, CYP81Q3 and C3H genes were measured in 10 sesame cultivars seeds (Yekta, early Palestinian, Naz tak shakheh, Naz chand shakheh, Oltan, Jiroft, Dashtestan 5, Dashtestan 2, Varamin and Karaj 1) by QRT-PCR technique and 18S rRNA gene as reference gene. Our findings showed that the level of CYP81Q1 gene expression was low in Early Palestinian that has low sesamin content. Therefore, this might not be considered as a qualitatively desired oil cultivar compared to others, whereas Yekta had the highest level of CYP81Q1 expression the best varieties for oil production both qualitatively and quantitatively. The highest expression level of CYP81Q2 was observed in Naz chand shakheh, while the lowest CYP81Q2 expression was found in Early Palestinian. Karaj1, Yekta and Dashtestan 5 showed the highest whereas Oltan had the lowest expression level of C3H. Karaj 1, Yekta and Dashtestan 5 were relatively from the late mature group that was reported to have higher contents of oil and sesamin than early ones.