为了确定Pb污染土壤对植物生态系统造成的影响,运用植物幼苗早期生长实验,研究了Pb不同浓度(50、100、200、300)对小麦幼苗叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)活性、可溶性蛋白含量、丙二醛(MDA)以及叶片中叶绿素含量的影响。结果表明,Pb污染土壤对小麦的生理系统产生明显的影响,小麦叶片可溶性蛋白含量可以很好的指示土壤Pb污染的胁迫。在Pb胁迫下,小麦叶片MDA含量并没有显著增加;小麦植株叶片POD酶活能够被诱导而升高,小麦叶片中SOD酶活性没有一致的变化规律;幼苗受到损伤的明显症状之一是叶片叶绿素含量下降;重金属对小麦幼苗的毒害机理之一是抑制了蛋白质的生物合成。
Changes in the activity of antioxidant enzymes including peroxidases (POD) and superoxide dismutases (SOD) and in the contents of chlorophyll (CHL),malondialdehyde (MDA),and soluble proteins (SP) in wheat (Triticum aestivum L) under the stress of Pb in soil were examined. The results showed a decrease of chlorophyll content in the leaves,and the concentrations of MDA and SOD level were not significantly increased. The POD activity could be induced to increase under the stress of Pb. The inhibition of protein biosynthesis by Pb was one of the toxic mechanisms involved. The activity of POD and SOD,contents of MDA and CHL could not be considered as biomarkers of stress by Pb in soil. While the contents of SP could be considered as biomarkers of stress by Pb in soil.