Effect of different levels of chitosan on the amounts and expression level of crocin and safranal genes in culture of saffron suspension (Crocus sativus L.)

Saffron (Crocus sativus) as an important medicinal and economical plant of Iran is rich in flavor, aroma and color, along with medicinal properties in addition to nutritional benefits. The effect of chitosan on Crocin and Safranal amounts as two important medicinal components and expression of their controlling genes in suspension culture of saffron was subjected as the aim of this study. For this purpose, saffron bulbs were cultured in ½ MS medium being treated with 100 and 150 mg/l of chitosan under cell suspension medium and callus optimal growth conditions. Samples were taken at 24 and 72 hours after the application of treatment in 3 replications. Measurement of secondary metabolites was done with HPLC and analysis of genes’ expression was performed with real-time PCR. The results showed that after the use of 100 and 150 mg/l of chitosan and after 24 and 72 hours, the two CsLYC and CsGT-2 genes expression significantly increased. Also, the results showed that Safranal and Crocin levels by the use of chitosan are significantly different at both harvesting times, so that 150 mg/l at harvest time of 72 hours after application of the treatment had the highest amount of Crocin and Safranal. Usage of chitosan as a bio-stimulant in the growth of medicinal and economic plants of saffron increased the amount of valuable secondary metabolites in the cell suspension culture of the plant.