Effectiveness of Tea Polyphenols Repair on Chromium Stress on Maize Seedlings
WANG He;HUANG Hui;Tianjin Nankai High School;College of Life Science,Tianjin Normal University;
The harm of the environmental pollution to human beings has become one of the world's most concerned problems. Heavy metal pollution, for instance, has aroused extensive concerns due to their severity and long term harmness. In this paper, the potential value of tea polyphenols in offsetting the heavy metal stress on the growth of maize seedlings was studied by taking chromium pollution as an example. In order to get rid of the interference of other factors in the soil, maize seeds were cultivated in a liquid medium, which contains different concentrations of K_2Cr_2O_7(0、10~(-5)、10-4,mM). When the seeds grew into their three-leaf period, the seedlings were rinsed with clean water to get rid of the heavy metal. Seedlings of each concentration were divided into two groups. The control groups still cultivated seedlings in clean water while the experimental groups kept them in a 0.05% tea polyphenols aqueous solution. After 25 days, physiological parameters of seedlings were measured. At a certain concentration, tea polyphenols could resist chromium stress by increasing SOD activities and POD activities. However, when the chromium concentration exceeded a certain threshold, tea polyphenols lost its function. So the activities of SOD and POD in root and leave increased under the stress of 10~(-5)mM chromium. Under the chromium stress and tea polyphenols repair, the expression of POD's isozymes and SOD's isozymes significantly changed. The current study tested stress induced cell viability of intact leaves of stress treatment and tea polyphenols repair by evans blue method. The results showed that different types of stresses caused leaf and root cell damages to different degrees and microscopic images fully demonstrated the effectiveness of tea polyphenols repair.
【CateGory Index】： X56;S513