Elicitation of flavonoids by chitosan and salicylic acid in callus of Rumex vesicarius L.

M. Sayed, S.E.A. Khodary, E.S. Ahmed, O. Hammouda, H.M. Hassan, N.M. El-Shafey
Secondary metabolites are synthesized and accumulated in plants in response to various stresses including elicitors and signaling molecules. In the current study, chitosan (50, 100 and 200 mM) and salicylic acid (SA) (200 µM) were evaluated as individual or combined elicitors of flavonoids in Rumex vesicarius callus. SA, in presence of fructose, was the most effective elicitor that significantly increased flavonoids accumulation (up to 99.2% over control), scored the highest scavenging activity and significantly stimulated phenylalanine ammonia lyase (PAL) activity. HPLC analysis indicated that while there was no detection of orientin, isoorientin, vitexin and isovitexin in control sample, they were detected (0.11, 0.04, 0.25 and 0.13 µg g-1 dry wt, respectively) in SA elicited callus. There was no correlation between flavonoids accumulation and the activity of superoxide dismutase (SOD), peroxidase (POX) and polyphenol oxidase (PPO) in the elicited callus, while a positive correlation between H2O2 and PAL or the accumulation of flavonoids was detected. Taken together, it could be concluded that SA is the best elicitor of flavonoids accumulation in Rumex vesicarius callus cultured on fructose. The superiority of SA to the other elicitors seems to be linked with the best management of H2O2 as signaling molecule in mediating SA-induced flavonoids.
Sayed, M., Khodary, S.E.A., Ahmed, E.S., Hammouda, O., Hassan, H.M. and El-Shafey, N.M. (2017). Elicitation of flavonoids by chitosan and salicylic acid in callus of Rumex vesicarius L.. Acta Hortic. 1187, 165-176
DOI: 10.17660/ActaHortic.2017.1187.18
Rumex vesicarius, flavonoids, elicitation, chitosan, salicylic acid

Acta Horticulturae