Salicylic Acid Alleviates the Cadmium Toxicity in Chinese Cabbages (Brassica chinensis)

Abstract

To test the effects of Salicylic Acid (SA) on physiological changes of plants under cadmium stress one cultivar of Chinese cabbage (Brassica chinensis) cadmium resistance, Changkenxiaobaicai (tolerance) were studied with pots cultures. Like other organisms Plants have adaptatives mechanisms whereby they are able to respond to both nutrient deficiency and toxicities. Plants materials were originated from the vegetable market in Wuhan, Hubei China. The seeds were tested on the pot cultures in the green house. The results of our experiments were quite different between the treatments. The combined treatment Cd 5 ppm + SA 500 mmol L(-1) during our experiment showed that the activity of peroxidase and superoxidase dismutase in the cabbages were induced, the total chlorophyll content increased significally by 25.38%, chl a/b about 43.01% and total biomass about 41.67%, both in comparison with the control. The soluble sugar content increased significantly to about 25.47% in comparison with the control. The electrolyte leakages were less affected. Under SA treatment only, the chlorophyll content, chl a/b content increased to about 18.85%, in comparison with the control. Plant biomass increased about 18.90% with the addition of SA in the culture. SA treatment can increase or decrease the Chinese cabbages metabolism. Plants were exposed to 5 ppm CdCl2 for 5 days under natural light. Then they were cultivated with Hoagland nutrient solution, which served as control, nutrient solution supplemented with 5 ppm CdCl2. Five days after Cd treatment, seedlings were harvested. The experiment was performed in triplicate.