Effects of PEG and Nano-Silica Elicitors on Secondary Metabolites Production in Crocus sativus L.

Dried stigmas of Crocus sativus L., is known as traditional medicine for anti-inflammatory, anti-cancer properties, and its associated with secondary metabolites of this plant. The present research was designed in order to study the effect of osmotic and nano-particles' stress on yield of anti-inflammatory compounds and the activity of several antioxidant enzymes in saffron. Polyethylen glycol (PEG) 6000 (12%) and solution of 2 mM of nano-silica were applied two weeks before flowering on the surface of potted plants. HPLC analysis and measuring the activity of antioxidant enzymes were done on samples from leaf and flower tissue in the control and treated plants. Outcomes showed that both PEG and nano-silica treatments elevated the content of crocin, picrocrocin, safranal, and crocetin and raised the activity of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) enzymes compared to the control treatment. The relative content of water was also increased by nano-silica and reduced with polyethylene glycol elicitors. It can be concluded that in saffron, osmotic adjustment under stress conditions results in biochemical responses as a secondary messenger which in turn induces the production of an appropriate secondary metabolite. Due to economic importance and increased demand of secondary metabolites and also high costs of their chemical synthesis, the application of PEG and nano-silica elicitors could increase secondary metabolites' production.