Differential Bio-Elicitor Effects on Bioactive Compound Production in Cichorium intybus Root Callus Cultures

Chicory (Cichorium intybus L.) roots are valued in medicine for their potential health benefits. Producing callus from chicory roots through tissue culture technology can streamline bioactive metabolites production and ensure a sustainable supply chain. The current study explored the impact of plant growth regulators (PGRs) and light conditions on the characteristics of callus induced from C. intybus root explants. The effect of fungal elicitors [yeast extract (YE), Fusarium oxysporum, and Aspergillus niger] on bioactive metabolite production from root-derived callus was investigated. Callus color varied notably between a 16/8 h light/dark cycle and complete dark, with differences in texture based on PGR concentrations and light conditions. High weights of callus formed were generally recorded under the 16/8 h light/dark cycle. Low concentrations of YE (1 g/L) and F. oxysporum (0.25 g/L) enhanced callus biomass fresh weight, while high concentrations of A. niger (1 g/L) improved callus dry matter significantly. The content and productivity of total phenolic were maximized at 1 g/L of YE and 1 g/L of F. oxysporum. Callus cultures elicited with a higher level of A. niger recorded the higher values of total flavonoid production. High-performance liquid chromatography (HPLC) analysis revealed significant variations in chlorogenic acid, catechin, and caffeic acid levels among the different elicited cultures. A. niger at 1 g/L notably increased chlorogenic acid content, while catechin levels were enhanced by specific concentrations of YE. Catalase (CAT) activity was significantly affected by different elicitors, while only the higher level of F. oxysporum and A. niger showed a significant increase in peroxidase (POD) activity. DPPH scavenging activity was elevated by all fungal elicitors. Principal Component Analysis delineated distinct variations in callus traits in response to different elicitors, with specific treatments showcasing enhanced biomass production, bioactive compound accumulation, and antioxidant activities. Through meticulous experimentation, this study paves the way for enhancing chicory root-derived products, ensuring sustainable production and potent bioactivity.