Naphthalene acetic acid and 6- benzylaminopurine induced phenolics, flavonoids and terpenoids in shoot cultures of Mesosphaerum suaveolens (L.) Kuntze and callus cultures of Ocimum basilicum L.

Mesosphaerum suaveolens (L.) Kuntze and Ocimum basilicum L. are sources of biologically important components like phenolics, flavonoids and terpenoids. These commonly growing wild plants with enormous medicinal value, have been mostly overlooked and used only as hedges for other economical crops. In vitro propagation of these plants would help to study the effect of different media components on important metabolites, including essential oils, pigments, antioxidants, food and flavouring agents which are of economic value. This study was focused on understanding the best suitable protocol and medium for the establishment of in vitro cultures of Mesosphaerum suaveolens and Ocimum basilicum. The work also focused on germination studies in both plants as a pre-requisite for culturing. The next focus was to understand how the culture conditions affected the amount of phenolics, flavonoids and terpenoids. Seedlings of M. suaveolens and fresh leaves of O. basilicum were inoculated and shoot cultures and callus cultures were obtained from them respectively, with different concentrations and combinations of Naphthalene Acetic Acid (NAA) and 6-Benzylaminopurine (BAP). The treatments used in the study for both plants were 0.5 mg/mL, 1.0 mg/mL, 1.5 mg/mL, 2.0 mg/mL, 2.5 mg/mL, 3.0 mg/mL, 3.5 mg/mL and 4.0 mg/mL each of NAA and BAP in combination. Among all the above combinations of the growth hormones on MS medium, 2.0 mg/mL combined concentration of NAA and BAP showed the highest biomass accumulation with the Total Phenolics Content (TPC) value of 17.58 ± 0.32 mg GAE/ g DW, Total Flavonoids Content (TFC) of 11516 ± 176.1 mg Quercetin/g DW and Total Terpenoids Content (TTC) of 80.25 ± 1.183 mg Linalool/g DW in M. suaveolens and 2.5 mg/mL combined concentration of NAA and BAP showed the highest biomass accumulation with the TPC value of 15.79 ± 0.13 mg GAE/g DW, TFC- 9513 ± 68.41 mg Quercetin/g DW and TTC of 75 ± 1.093 mg Linalool/g DW in O. basilicum. The levels of phenolics and terpenoids were higher in M. suaveolens whereas the levels of flavonoids were higher in O. basilicum. This study would help in further understanding other aspects of plant defense in these plants grown in vitro.