THE EFFECT OF PLANT GROWTH REGULATORES AND METHYL JASMONATE ON FLAVONOID PRODUCTION AND ANTIOXIDANT ACTIVITY IN CALLUS AND SUSPENSION CULTURES OF TWO Dracocephalum SPECIES

Members of the genus Dracocephalum (Lamiaceae) are known to contain numerous bioactive secondary metabolits. In the present work, the influence of plant growth regulators and methyl jasmonate on biomass increase, flavonoid production and antioxidant activity in callus tissues and cell suspension cultures of Dracocephalum moldavica and Dracocephalum kotschyi was studied. Callus and cell suspension cultures were established using leaf, stem and petiole explants of in vitro grown plantlets. Induction and proliferation of callus tissues were conducted on MS media supplemented with BAP and NAA or 2,4-D and kinetin. Callus induction and growth were varied among explants, treatments of plant growth regulators and examined populations. The highest callus induction and growth parameters were obtained on the culture medium supplemented with 2 mgl-1 NAA and 1 mgl-1 BAP using shoot explants. Cell growth curves were divided during four weeks to three stages including lag, linear and death phases. The antioxidant potential of the methanolic extract correlated with flavonoid accumulation. The maximum flavonoid production and antioxidant activity were observed in the medium containing 2 mgl-1 NAA and 1 mgl-1 BAP from shoot explants. Flavonoid accumulation and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity were decreased in the presence of methyl jasmonate as the elicitor. Overall, significant differences in callus induction and growth, flavonoid accumulation as well as antioxidant activity were observed among the populations. These results shed more light on production of desired secondary metabolites in D. kotschyi and D. moldavica and provide a basis for more investigations.