Species-Specific Secondary Metabolites from Primula veris subsp. veris Obtained In Vitro Adventitious Root Cultures: An Alternative for Sustainable Production

Abstract

Primula veris subsp. veris L. is a perennial herbaceous and medicinal plant species the roots and flowers of which are a source of valuable pharmaceutical raw materials. The plant tissues are used to produce expectorant and diuretic drugs due to their high content of triterpene saponins and phenolic glycosides. Underground roots of P. veris can be obtained only through a destructive process during the plant’s harvesting. In the present study, an in vitro adventitious root production protocol was developed as an alternative way of production, focused on four species-specific secondary metabolites. Root explants were cultured in Murashing & Skoog liquid medium supplemented with 5.4 μM α-naphthaleneacetic acid, 0.5 μM kinetin, L-proline 100 mg/L, and 30 g/L sucrose, in the dark and under agitation. The effect of temperature (10, 15 and 22 °C) on biomass production was investigated. The content of two flavonoid compounds (primeverin and primulaverin), and two main triterpene saponins (primulic acid I and II) were determined after 60 days of culture and compared with 1.5-year-old soil-grown plants. The accumulated content (mg/g DW) of bioactive compounds of in vitro adventitious roots cultured under 22 °C was significantly higher than the other two temperatures of the study, being 9.71 mg/g DW in primulaverin, 0.09 mg/g DW in primeverin, 6.09 mg/g DW in primulic acid I, and 0.51 mg/g DW in primulic acid II. Compared to the soil-grown roots (10.23 mg/g DW primulaverin, 0.28 mg/g DW primeverin, 17.01 mg/g DW primulic acid I, 0.09 mg/g DW primulic acid II), the in vitro grown roots at 22 °C exhibited a 5.67-fold higher content in primulic acid II. However, primulic acid I and primeverin content were approximately three-fold higher in soil-grown roots, while primulaverin content were at similar levels for both in vitro at 22 °C and soil-grown roots. From our results, tissue culture of P. veris subsp. veris could serve not only for propagation but also for production of species-specific secondary metabolites such as primulic acid II through adventitious root cultures. This would therefore limit the uncontrolled collection of this plant from its natural environment and provide natural products free from pesticides in a sustainable way.

A terpenoids database with the chemical content as a novel agronomic trait

“…The production of natural products is important for functional research and commercial development ( 42 ). But, for the vast majority of natural products, it is the most important factor which limits their further development and research due to their low content in plant tissues and the long growth cycle of plants ( 43 ).…”

The Optimization of Medium Conditions and Auxins in the Induction of Adventitious Roots of Pokeweed (Phytolacca americana L.) and Their Phytochemical Constituents

“…These studies demonstrated that auxin can be used to establish in vitro root culture for phytochemical production, but the appropriate type and concentration of auxin for pokeweeds need to be studied. Additionally, root induction in liquid medium can promote root growth and the production of phytochemicals due to better nutrient circulation than solid medium [ 26 , 27 ]. Therefore, this study established appropriate medium states and plant growth regulators (PGRs) for in vitro pokeweed adventitious root induction from leaf explants, considering root growth and phytochemical parameters.…”

Comparative Phytochemical Analyses of Flowers from Primula veris subsp. veris Growing Wild and from Ex Situ Cultivation in Greece

“…veris at the Hellenic Agricultural Organization-Demeter in 2020 [ 25 ], following an optimized protocol for the micropropagation of cowslip via shoot tip explants derived from seedlings, in order to facilitate the mass production of plants and the sustainable cultivation of the plant species. This approach has also been followed by the cultivation of roots [ 30 , 31 ].…”