小白菜叶内叶绿素和抗氧化系统对芘胁迫的动态响应

通过盆栽试验,研究了土壤中芘胁迫对小白菜叶内叶绿素及抗氧化系统动态变化的影响。结果表明,芘胁迫对小白菜叶片叶绿素a、叶绿素b、叶绿素a＋b和类胡萝卜素的动态影响基本一致,都是在第18d苗期时随着芘浓度的增加显著降低,25d开始各处理的含量差异不显著。小白菜叶片的CMP、MDA和AsA均随种植时间的延长呈现先升高再降低的过程,39d时CMP达到最高值,施芘处理显著高于对照;MDA在32d时上升至最高值,且随着芘浓度的增加而增大,39d以后急剧下降并维持在较低水平,各个处理间差异不显著;46d时AsA含量达到峰值,高浓度芘处理极显著高于对照。游离脯氨酸在25d时随芘浓度的增加而急剧增加,32d以后逐渐下降,各处理间差异不显著。小白菜叶片的CAT活性在种植期间呈下降趋势,39d时随芘浓度的增加有所提高;与CAT活性的变化趋势相反,POD活性随种植时间的延长呈上升趋势,39d和46d时高浓度处理的POD活性显著高于对照。

Dynamics Response of Pyrene Stress on Chlorophyll and Antioxidative System in Leaves of Chinese cabbage

The effects of pyrene stress on the dynamics change of chlorophyll and antioxidative system in leaves of Chinese cabbage were studied through experiment of flowerpot cultivation in soil. The results showed as follow：the dynamics influence of chlorophyll a,chlorophyll b ,chlorophyll a＋b and carotenoid pigment contents presented similar trend. They all reduced by increasing pyrene concentrations at 18 days and became no significant differences among them from 25 days to 46 days. The contents of CMP,MDA and AsA in leaves of Chinese cabbage all raised at first and then decreased with time. The maximum content of CMP was observed at 39 days and increased significantly in pyrene treated soil than in control soil; The MDA contents reached the top value at 32 days and increased with pyrene treatments, then reduced sharply at lower levels after 39 days without significant differences in treaments; The AsA contents were observed the highest values at 46 days and high pyrene concentration treatment increased extrcmelly than control treatment. The contents of Pro increased sharply with in- creasing pyrene concentration at 25 days, then reduced gradually and changed indistinctively in treatments after 32 days. The activities of CAT reduced with planting time and increased with pyrene treatments at 39 days. On the contrary, the POD activities were stimulated with growing time and the results of high level treatments increased significantly with CK at 39 days and 46 days.