The effect of IAA on stress resistance of tobacco seedlings (Nicotiana plumbaginifolia) under in vitro culture conditions

In this study, the effect of IAA on salt tolerance of tobacco plants (Nicotiana plumbaginifolia) was investigated under in vitro culture conditions. Material and Methods: Sterile seeds of N. plumbaginifolia were cultured in MS medium. In vitro propagated seedlings under tissue culture conditions were treated with IAA (mg / l) and salinity (0, 100 and 200 mM) for 4 weeks. Physiological and biochemical parameters including H2O2, chlorophyll, soluble carbohydrate, protein and antioxidant enzyme activity were measured. Salt stress increased H2O2, proline, catalase, superoxide dismutase and ascorbate peroxidase, while reverse patterns were observed for photosynthetic pigments, soluble carbohydrates and also total protein. In salt-treated seedlings, application of auxin increased proline, catalase and H2O2, but decreased photosynthetic pigmentation, soluble carbohydrates, total protein and some enzymes such as superoxide dismutase and ascorbate peroxidase. Auxin treatment in salt-treated tobacco seedlings improved salinity tolerance by changes in some physiological parameters.