Effect of salicylic acid on antioxidant enzymes of Chinese fir seedling under drought-stress

To study the effects of auto-toxic substances, salicylic acid (SA), on Chinese fir, antioxidant enzyme activity of Chinese fir treated with different concentrations of SA under different degrees of drought-stress (different concentrations of PEG) was investigated. Results show that under slight (-0.3 MPa) and moderate (-0.5 MPa) drought-stress, superoxide dismutase (SOD) activity initially increases, followed by a subsequent decrease, and then sharp decline. Under severe drought-stress (-0.7 Mpa), SOD activity decrease linearly. POD activity shows an initial decline, followed by a rise for a maximum of 21 days under slight drought-stress. However, POD activity shows an overall decline under moderate to severe drought-stress.