Investigation of the effects of yeast extract on isoflavone synthase gene expression and some biochemical parameters in Glycine max seedlings

Several studies have been investigated the effects of Yeast extract (YE) on morphological and biochemical properties of various plant species. In this research, isoflavone synthase (IFS) gene expression profile, flavonoid and anthocyanin contents and also activity of some antioxidant enzymes have been assessed in 9-day soybean (Glycine max) seedlings which were treated with various concentrations of YE for 8 and 16 hours. Soybean as an annual plant is a member of the Leguminoseae family. Its seeds are containing of isoflavonoid compound (such as genestin and dedzein) which produce through IFS catalyzes from flavonone precursor. Results showed flavonoid and anthocyanin contents, IFS gene expression and also protein content significantly increased in elicited seedlings in compared to that of the control, but more significantly at 16- hour treatment. On the other hand, activity of antioxidant enzymes including superoxid dismutase, catalase and peroxidase was also elevated in treated seedlings rather than of the control that was more remarkable at 8-hour treatment. Based on the results, it can be concluded that treated soybean seedlings with YE lead to induce an oxidative stress. In this condition, while at 8-hour elicitation time the enzymatic antioxidant systems is more active, higher activity of the non-enzymatic antioxidant system (phenyl propanoid pathway) was seen for 16 hours treatment. Therefore, it seems that YE-treated for 16 hours is optimal for inducing of gene expression and also biosynthesis of active ingredient in this plant.