| The effectiveness of activitiy of antioxidant enzymes as evaluation index for salt tolerance were investigated
in five trees differing in tolerance to salt stress by determining the malondialdehyde (MDA) content and the activities of
antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX).
The results showed that MDA contents of the five trees increased significantly under salt stress. The increasing scales of
MDA contents of Syringa microphylla and Pinus sylvestris var. mongolica were larger than that of Ulmus pumila and
Lycium dasystemum. The SOD and CAT could serve as reliable indicators for appraising salt tolerance of woody plants, and
SOD and CAT were more effective. With the increase of stress intensity, the SOD activities of U. pumila and L.
dasystemum increased, while those of S. microphylla and P. sylvestris var. mongolica decreased obviously. POD and APX
were not reliable selction criteria. Increase in POD activity did not seem to be a tolerance component, but a stress
symptom. |
