N. O. Kovalenko, Zh. I. Bilyk, T. A. Palladina

Kholodny Institute of Botany, National Academy of Sciences of Ukraine, Kyiv;
e-mail: tatiana_palladina@ukr.net

Salinity is a hard stress factor for plant organisms which negative effect is caused chiefly by sodium toxic for plants. Plant cells try to remove Na⁺ from their cytoplasm outside and to vacuolar space by secondary active Na⁺/H⁺-antiporters. Their functions can be intensified by gene engineering methods­ however we try do it with the help of non-toxic bio­active preparations. A comparison of their effect on the plasma membrane of Na⁺/H⁺-antiporters was carried out on corn seedling roots of Zea mays L. exposed at 0.1 M NaCl. Before we have established that Methyure used by seed pretreating possesses a high salt protective ability as against Ivine. It was found that without NaCl exposition Na⁺/H⁺-antiporter­ activity in root plasma membrane was nearly unnoticeable but increased slightly with seedling age. Methyure and Ivine did not influence its activity in control root seedling. One day 0.1 M NaCl exposition evoked a considerable increasing of Na⁺/H⁺-antiporter activity and its gene expression but these effects disappeared at 10 day NaCl exposition. Methyure use reinforced Na⁺/H⁺-antiporter activity and prolonged it at NaCl exposition without effect on its gene expression whereas Ivine effects on these indexes were insignificant. Obtained results showed that the salt protective capability of Methyure is connected with plasma membrane Na⁺/H⁺-antiporter activation which is realized on molecular level.