Changes of antioxidant enzyme activities and isoenzyme profiles during in vitro shoot formation in saffron (Crocus sativus L.).

Among the different concentrations of Thidiazuron (TDZ) and between the two media Gamborg (B5) and Murashige and Skoog (MS), the highest frequency of shoot formation could be seen in the MS medium with TDZ concentration of 4.54 microM. Among the different concentrations of Naphtalene acetic acid (NAA) and Benzyl adenine (BA) in the two aforementioned media, the maximum proliferation and rooting of saffron shoots were obtained in a B5 medium containing 2.22 microM NAA and 2.68 microM BA. Peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), esterase (EST) and polyphenoloxidase (PPO) measurements proved that all the enzymes had a similar pattern of changes, according to which their concentrations increased in the first stages of development and then decreased. The same pattern was observed for polyphenoloxidase in a B5 medium while in the MS medium a reverse pattern was observed. The enzyme concentration decreased and then increased during shoot formation. The results show the principal role of antioxidant enzymes in the complicated process of organogenesis.