Physiological Responses of Krishum (Iris lactea Pall. var. chinensis Koidz) to Neutral and Alkaline Salts
2008
Wang, Y. | Guo, J.X. | Meng, Q.L. | Cui, X.Y.
The aims of this study were to compare the physiological responses of krishum (Iris lactea Pall. var. chinensis Koidz) to neutral and alkaline salt stress and identify and examine the mechanisms involved in plant response to salt treatments. In this study, biomass, ion accumulation (Na⁺, K⁺, Ca²⁺, Mg²⁺), organic solute (proline) concentration, rate of membrane electrolyte leakage (REL) and antioxidase activities including those of superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6) and peroxidase (POD, EC 1.11.1.7) were investigated in krishum under different concentrations of NaCl, Na₂CO₃ and the mixture of the two salts in the same volume. All three treatments caused increases in Na⁺ concentration, proline content and REL and decreases in root Mg²⁺ and K⁺ content. Increased Ca²⁺ and antioxidase activities were observed at lower external Na⁺ concentrations. However, at higher external Na⁺ levels, decreased Ca²⁺ and antioxidase activities were detected. Alkaline salt resulted in more damage to krishum than neutral salt including lower SOD, POD and CAT activities and decreased proline content, relative to neutral salt. High Na⁺ and low K⁺ in krishum intensified ion toxicity under alkaline condition. Alkaline salt caused greater harm to plants than neutral salt, the primary reason of which might be the lower Ca²⁺ content in the plant under alkaline salt stress.
显示更多 [+] 显示较少 [-]