In vitro production of chlorogenic acid in culture of transformed Cichorium intybus L.: Plants

Abstract

Chicory (Cichorium intybus L.) is traditionally recognized for its antiinflammatory, antimicrobial, anticancer and nutritive properties. Among active secondary metabolites detected in chicory, the most important are sesquiterpene lactones and phenolics, including chlorogenic acid (CA). Hereby we have analyzed the content of CA in previously obtained Agrobacterium rhizogenes - transformed chicory hairy root cultures and transformed regenerants. Among three analyzed hairy root clones, clone 13 had exceptionally high biomass production, so the amount of CA in this culture was the highest, e.g. 400 times higher in comparison to the untransformed root culture. Since the roots spontaneously regenerated, the system was upgraded to allow the comparison of CA content not only among the clones, but also between different developmental phases of the regenerants (vegetative vs. flowering plants) and their organs (roots vs. leaves). It was shown that the CA production varies from clone to clone, and also depends on the phenophase of the clone. In the rosette stage of clones 13 and 36, the highest amount of CA was detected in roots, while the same clones in the flowering stage had significantly lower CA content. The clone 35 in the vegetative phase produced the lowest amounts of CA. However, in the flowering stage the roots of clone 35 produced the highest CA amount. Among the regenerants, the clone 13 had the fastest growth, and hence the best CA production. The current paper presents for the first time the CA content in transformed chicory regenerants. The obtained results suggest that the culture of transformed chicory plants can be equally good source of CA as liquid hairy root culture.