Influence of Auxins, Cytokinins and Biotic Elicitors on Accumulation of Memory Enhancer Compound Bacoside-A in Tissue Culture of Bacopa monniera (L.) Pennell.

摘要

The effects of the auxins [indole-3-acetic acid (lAA), 1-napthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D)], cytokinins [6-benzyladenine (BA), Kinetin (Kin) and thidiazuron (TDZ)] and biotic elicitors were evaluated individually and in combinations, on callus proliferation, shoot growth and accumulation of bacoside-A through liquid and semi-solid nutrient media. Maximum shoot proliferation (19.4 ± 0.91 shoots/explant) was observed in liquid MS medium containing 5 muM BA, which was 1.3 times higher than semi-solid MS medium fortified with same concentration of BA. The callus and shoots showed sustained growth and accumulation of bacoside-A even after two years of initiation of subcultures. The nature of nutrient media did not influence the accumulation of bacoside-A in shoot biomass. Except for Saccharomyces cerevisiae-derived elicitors that showed about a 20% increase in shoot biomass production, the growth of callus as well as shoots was inhibited after the addition of otherfungal elicitors in MS medium. Among the shoot and callus cultures exposed to Pencillium notatum, Rhizopus stolonifer, Coriolus versicolor, Mucor sp. and S. cerevisiae-derived elicitors, incorporation of 750 mg/1 S. cerevisiae or Mucor sp. showed about 3.2- and 1.7-fold higher production of bacoside-A in callus and shoot biomass, respectively. This protocol would be helpful in reducing pressure on natural populations of Bacopa monniera (L.) Petmell. harvested indiscriminately for bacoside-A.