Abstrakt: |
Abstract: The present study investigated differences in cadmium resistance of two wheat (Triticum aestivum L.) cultivars. The cvs. RAJ 4161 (Cd resistant) and PBW 343 (Cd sensitive) were treated with 200 mg(Cd) kg-1(soil) for 3, 5, 7, and 10 d. The effect of the Cd stress was estimated by measuring growth parameters, accumulation of cadmium, sulphur, and glutathione (GSH), and by expression of some defence genes [phytochelatin synthase (PCS), glutathione reductase (GR), and ascorbate peroxidase (APX)]. The Cd treatment resulted in a significant reduction in plant growth and in an increase in the accumulation of S and GSH. Further, the expressions of PCS, GR, and APX were also mostly enhanced. The PCS was upregulated significantly in roots of RAJ 4161 (0.6-fold) and downregulated (0.9-fold) in PBW 343 on day 3 of the Cd treatment. In RAJ 4161, the expressions of APX and GR recorded a maximum increase of 2.1- and 2.4-fold in roots and leaves, respectively, after 10 d of the stress. The results show that a different ability of RAJ 4161 and PBW 343 to modulate mRNA expression after the Cd treatment was related to their Cd tolerance. |