Effect of Cr~(3+) Stress on the Growth Characteristics of Lettuce Seedlings

In this article,the indoor sandculture under the condition of different Cr3+ concentrations was used to study the change of the chlorophyll synthesis,the contents of proline and soluble sugar,oxidative damage degree and the activity of antioxidant enzyme,etc.The results indicated that Cr3+stress(≤40mg/L) had some stimulativing effect on chlorophyll synthesis,the contents of chlorophyll was the highest up to about 145% of the control at the concentration of 40 mg/L;Cr3+stress(≤80mg/L) could induce and improve the activity of SOD and POD,which reached a maximum,respectively 253% and 287% of the control;the content of soluble sugar in plant body presented increasing trend at Cr3+concentration≤80mg/L and was 207% of the control at the concentration of 80mg/L;under higher Cr3+ concentration(80mg/L),the enzyme activity were inhibited,soluble sugar content was also declined,the enzyme activit of SOD,POD and the content of soluble sugar respectively were 27%,31% and 24% of the control at Cr3+ concentration of 320mg/L;the contents of proline and MDA increased with increasing of Cr3+ concentration.