Comparative analyses of secondary metabolites in microshoot culture, callus culture, and native plants of Atraphaxis L. (Polygonaceae)
摘要
For the first time, in vitro propagation of Atraphaxis davurica Jaub. & Spach, A. davurica var. chikoensis Yurtseva & Mavrodiev, and A. selengensis Yurtseva & Mavrodiev was developed, and callus cultures of Atraphaxis species were obtained. Qualitative and quantitative analyses of secondary metabolites and of antiradical activity in microshoots and callus cultures were performed in comparison with natural specimens. Biochemical composition of natural specimens of A. davurica, A. davurica var. chikoensis, and A. selengensis is also reported for the first time. The Murashige–Skoog medium supplemented with 0.5 µM 6-benzylaminopurine was chosen as the optimal medium for the in vitro propagation. Calluses were obtained from stem internode explants on the Murashige–Skoog medium supplemented with 5 µM 6-benzylaminopurine and 2.5 µM α-naphthaleneacetic acid. Eighteen phenolic compounds, including (+)-catechin, L-epicatechin, quercetin, and emodin, were detected in the studied samples by HPLC. Catechins and flavonols, which were not specific to the natural specimens, were present in callus culture. Callus culture of A. davurica is characterized by a high level of (+)-catechin (1.44 mg g−1). Microshoots of these species showed a high concentration of some flavonols (up to 3.85 mg g−1). The in vitro culture had a high level of anthraquinones (1.44–4.62 times higher than that in natural specimens). Thus, in vitro culture of Atraphaxis species has good potential for enhanced production of catechins, tannins, phenolic acids, anthraquinones, and some flavonols. Furthermore, cell suspension cultures can be implemented from calluses: a promising avenue for large-scale production of biologically active compounds.