The Effect of Nutritional Factors and Plant Growth Regulators on Micropropagation and Production of Phenolic Acids and Saponins from Plantlets and Adventitious Root Cultures of Eryngium maritimum L.

Abstract

Eryngium maritimum L. is a valuable medicinal species, but since it is protected plant, collection from natural populations is forbidden. Therefore, establishing an efficient system for micropropagation of this species is desirable. To determine the optimal nutritional factors needed for shoot multiplication, root development and secondary metabolites accumulation, different media and plant growth regulators were tested. The highest plant regeneration efficiency (over 96 %), with 4.4 shoots per explant was induced on Murashige and Skoog (MS) medium supplemented with 1.0 mg L−1 benzyladenine (BA) and 0.1 mg L−1 indole-3-acetic acid (IAA). The in vitro-regenerated shoots were rooted (83.3–100 %) and transferred to an experimental plot with 62 % efficiency. Flow cytometric analysis revealed no variation in nuclear DNA content in field- and in vitro-delivered plant material. Ultra high performance liquid chromatography (UHPLC) indicated that multiple shoots and roots from in vitro-regenerated plantlets and adventitious root cultures maintained the production of rosmarinic (RA) and chlorogenic (CGA) acids and triterpenoid saponins found in the rosette leaves and roots of E. maritimum intact plants. UHPLC revealed a 12-fold increase of RA and CGA and 3.2-fold higher accumulation of triterpenoid saponins in roots of in vitro-derived plantlets in comparison to roots from field-grown plants. Adventitious root cultures allowed continuous growth of excised root in liquid media with or without exogenous auxins. The roots grown in liquid medium supplemented with 0.1 mg L−1 IAA showed higher (227-fold) phenolic acids accumulation than those without auxin. Obtained results confirmed that micropropagation is a useful strategy in the protection of endangered species and a renewable source of a high quality plant material for secondary metabolites production.