The Effects of Elicitor and Abiotic Stressor Molecules on Phenolic Composition of in Vitro Callus Cultures of Elecampane (Inula Helenium L.)

Abstract

This study focused on the effects of various stressors and elicitors on phenolic metabolism of in vitro callus cultures of Elecampane. 1 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D) + 0,3 mg/L Kinetin (KN) formulation was detected as the most proper application for callus production. Quercetin was synthesized as the dominant phenolic compound of callus cultures. The highest values of total phenolics were obtained through the combination of 6-Benzylaminopurine + 1-Naphthaleneacetic acid (BAP+NAA) in the plant growth regulators (PGR) group (169 mu g/g), 1/2 reduced Murashige and Skoog medium (MS) (108 mu g/g) in the stressor group, and both abscisic acid (140 mu g/g) and melatonin (138 mu g/g) in the elicitor group. The application of various PGRs and elicitors enhanced the level of quercetin at pronounced levels (241-388 mu g/g), but not in rutin (3-18 mu g/g). Chlorogenic acid increased under silver nitrate (19 mu g/g) and 1/4 reduced MS stressors (17 mu g/g) and melatonin (32 mu g/g) and abscisic acid (24 mu g/g) elicitors. These findings suggest that the combination of 2,4-D + KN, reduced MS, abscisic acid, and melatonin conditions stimulated the synthesis of phenolics through the biosynthetic pathway by increasing the stress resistance of Elecampane.