Detection and extraction of anthocyanin in wild type and mutants of Arabidopsis thaliana
Plants respond to environmental challenges by physiological, metabolic and developmental changes. For this thesis, we used Arabidopsis thaliana which belongs to the family Brassicaceae. It serves as a model plant because it has a small genome, is easy to grow, has a short life cycle, and produces thousands of seeds per plant. Various wild type forms and a large array of mutant lines of Arabidopsis are readily available for research. The focus of this research was on the production of anthocyanins under stress conditions. Anthocyanin is produced by plants in response to many unfavorable conditions including light and pathogen infections. Preliminary experiments revealed that when Arabidopsis were subjected to treatments with various plant hormones such as JA, Salicylic acid and ethylene, this stress response was activated. Alamethicin (Ala), a peptide that creates voltage-gated ion channels in membranes, has been demonstrated to activate many of these hormones and may thus also activate the production of anthocyanin. Plants were therefore treated with different hormones and Ala and the production of anthocyanin was monitored. Likewise, plants were exposed to ultraviolet (UV) light and monitored the stress response for anthocyanin production. Anthocyanin absorbs light in the UV range and protects plants from the damaging effects of UV. To gain further insights into the regulatory mechanisms, several Arabidopsis wild type and mutant lines were analyzed in a comparative study. It was found that only JA causes the accumulation of anthocyanins and may thus be the major regulator of this process. In contrast, salicylic acid and ethylene do not seem to have a significant effect on the production of anthocyanins. Surprisingly, Ala also did not cause the accumulation of anthocyanins despite the fact that it induced JA.