Effect of activated charcoal on the developmental patterns, polyphenolics productivity and photosynthetic activity of Sideritis scardica in vitro

Sideritis scardica is a Balkan endemic species traditionally used for the treatment of pulmonary emphysema and angina pectoris [1]. It is threatened in half of the countries of its occurrence (less than 2,500 mature individuals in Bulgaria and over 250 in Serbia) [2]. The intensive collection pressure has imposed the necessity of its conservation by means of in situ and in vitro approaches. Tissue culture of the plant has been initiated by surface sterilization of its seeds, collected in the Slavjankae Mountain in Bulgaria. As a part of a broader program for the biotechnological delivery of phytopharmaceuticals with antioxidant activity of this plant, modifications of organic and inorganic factors of the culture medium have been experimented. Here we present the results of the effect of activated charcoal (AC) on S. scardica shoot cultures. Low (0.02, 0.05) as well as high (0.2 and 0.5 g/l) concentrations has been applied. It was established that the higher AC concentrations (0.2 and 0.5 g/l) led to a profound stimulation of axillary shoot formation, enlargement of leaf area and stimulation of polyphenolic production. The values obtained for photosystem II quantum yield revealed that the control (untreated) and all carbon-treated variants were physiologically fit. However, a slower apparent electron transport rate for 0.2 and 0.5 g/l treated plants was established, as compared with the control and 0.02 and 0.05 g/l treated ones. It appears that the production of higher leaf mass and the increase in leaf area in 0.2 and 0.5 g/l treated S. scardica is a compensatory reaction/mechanism that allows for more efficient light utilization. The remarkable effect of activated charcoal on biosynthetic capacity and physiological status of the plant, without the addition of organic supplements such as plant growth regulators, seems to be a prospective approach in tissue culture optimization of the plant in vitro.

Acknowledgements: Swiss National Science Foundation in the Framework in the Bulgarian-Swiss Research Program (BSRP, grant No. IZEBZO_142989; DO2 – 1153); World Federation of Sciences – Bulgarian National Scholarship Programme for young researchers (P.K; N.P.).

Keywords: Balkan endemic Sideritis scardica, in vitro, activated charcoal, photosynthetic activity, polyphenolics production, developmental patterns.

References:

[1] Ivancheva S, Stantcheva B. Ethnobotanical inventory of medicinal plants in Bulgaria. J Ethnopharmacol 2000; 69: 165 – 172

[2] The IUCN Red List of Threatened Species, http://www.iucnredlist.org/details/203271/0