Tetraploid Black Locust (Robinia Pseudoacacia L.) Increased Salt Tolerance by Activation of the Antioxidant System

ABSTRACT

Polyploid plants are reported to have strong tolerance to environmental stress. In this study, we investigated the effects of salt stress on the concentrations of salt ion, MDA, O₂^.-, H₂O₂, and the activities and isoenzymes of antioxidant enzymes (superoxide dismutase [SOD]), catalase [CAT], peroxidase [POD], and ascorbate peroxidase [APX]) in diploid and tetraploid Robinia pseudoacacia L. In diploids, salt treatment induced accumulation of salt ions and increasing of MDA, O₂^.-, and H₂O₂. The concentrations of salt ion, MDA, O₂^.-, and H₂O₂ in tetraploids were lower than those in diploids, while the activities of SOD, CAT, and APX remained at a higher level. These results indicted that tetraploid R. pseudoacacia have a stronger antioxidant defense system and increased salt tolerance.

Keywords:

• Robinia pseudoacacia L.
• diploid
• tetraploid
• salt stress
• antioxidant enzymes