Chicory (Cichorium intybus L.) is a typical Mediterranean plant distributed throughout the world and has different commercial uses such as salad, forage, inulin production, and coffee substitute. Health promoting characteristics of inulin as a prebiotic compound led to its biosynthesis pathway discovery. Two enzymes, namely, 1-SST and 1-FFT, are involved in inulin biosynthesis during normal phase. By cold nights or other factors, 1-FEHs enzymes degrade inulin to fructosyl units. To compare the strength of function of these genes in a wild type genotype with root type cultivar (Orchies) of chicory at three stages, i.e. 60, 90, and 120 days after seed planting, relative expression of those genes along with their corresponding metabolites were assessed using RT-qPCR and HPLC. Expression results showed that, unlike Orchies cultivar, relative expression of 1-SST in wild type genotype was ascending, relative expression of 1-FFT was very low and constant and there were high levels of relative expression of 1-FEH I gene during growing season due to flowering initiation. Also, glucose and fructose concentrations were upward, as result of 1-SST and 1-FEH I enzymes activity in wild type genotype, respectively. Degree of Polymerization (DP) of produced inulin had almost no increase due to low function of 1-FFT enzyme in the wild type genotype (DP< 5), but Orchies cultivar produced inulin with DP> 10 as expression of 1-SST decreased during growing season. So, it is possible to make inulin pathway in root type chicory cultivars more efficient by expanding and overexpressing 1-SST function using such wild resources through backcross breeding or biotechnology methods.
