Effect of Cyanobacterial Extract on Medicinal Plant Mentha piperita L

As the simplest photosynthetic organisms, cyanobacteria are the interface between bacteria and plants in terms of evolutionary process. The positive effect of these photosynthetic microorganisms on plant growth is one of the important roles in biotechnology. Their production of various secondary metabolites is another known application of these microalgae in agricultural biotechnology. In this study, the effect of two species of heterocystous cyanobacteria, isolated from paddy fields of Golestan Province in Iran, on the growth of peppermint (Mentha piperita L.) was evaluated. A significant difference was observed between treated plants and control in terms of growth parameters. In addition, as one of the factors influencing the vegetative parameters of plants, the qualitative identification of phytohormones in cyanobacterial biomass was investigated by biochemical methods and High Performance Liquid Chromatography technique. The results indicated the presence of plant growth hormones such as indole acetic acid and indole butyric acid in extracts of studied cyanobacteria.