The comparative effects of nano and bulk size particles of CuO and ZnO on glycyrrhizin and phenolic compounds contents in Glycyrrhiza glabra L. seedlings

Abstract

Elicitors such as heavy metals are used to stimulate secondary metabolite production in plants. In this study the effects of bulk and nano size of ZnO and CuO particles on some secondary metabolites were compared in licorice seedlings. To this aim, content of reducing sugars (as precursor of secondary metabolites), proline, glycyrrhizin, total phenolic compounds, flavonoids, anthocyanins and tannins were measured and compared in 21 days seedling of Glycyrrhiza glabra under 1 and 10 µM of each nano particles of zinc oxide, copper oxide (nZnO, nCuO), or bulk size particles of zinc oxide and copper oxide (bZnO, bCuO). Mean of data compared using one-way analysis of variance and Duncan’s test. The concentration of 10 µM bulk size particles of zinc oxide decreased the content of reducing sugars. The contents of glycyrrhizin, total phenolic compounds, flavonoids, anthocyanins and proline were increased by 1 and 10 µM of nZnO and bCuO. 10 µM bZnO treatment increased the content of tannins in G. glabra seedlings. From the results it could be concluded that bulk and nano size ZnO and CuO particles affect secondary metabolite production of licorice seedlings in different patterns.