Effect of chitosan and light conditions on the production of callus biomass, total flavonoids and total phenolics in Ginkgo biloba L.
Ahmed A. Elateeq, Z. H. Saad, Mohamed A. Eissa, Saif Ullah
Abstract
Ginkgo biloba L. is a well-known tree for its high medicinal value owing to the presence of terpene trilactones, unique active metabolites, and other phytochemicals, including flavonoids and phenolics in its leaves. In Egypt, G. biloba has been reported as one of the endangered trees. Hence, plant tissue technique could be a potential alternative system to produce ginkgo’s pharmaceutical compounds. In this study, an elicitation strategy using the biotic elicitor chitosan was employed to enhance the productivity of certain metabolites in G. biloba leaf-derived callus incubated in light (16 h photoperiod) or darkness. Combination of 1.0 mg/L α-naphthalene acetic acid (NAA) and 2.0 mg/L 6-benzyl adenine (BA) added to Murashige and Skoog (MS) medium resulted in the highest callogenesis percentage in both light and dark (95.00 and 94.43%, respectively) with a compacted callus texture but a different color. Significant differences were recorded between chitosan levels concerning callus biomass production and total flavonoids and phenolics accumulation. The highest yield of callus fresh and dry weights, growth index, and relative growth rate were recorded for light-grown cultures elicited with 100 mg/L chitosan followed by 50 mg/L. Same concentrations were also superior in enhancing the content and productivity of total flavonoids and total phenolics. Light incubation was more favorable than darkness for callus growth, flavonoid, and phenolic biosynthesis as well as antioxidant activity. The current study revealed the possibility of using calli culture as a biotechnological approach for the industrial production of G. biloba phytoconstituents.