【摘要】 通过盆栽试验，分别设置对照（CK）、Q1、Q2和Q3[土壤铅（Pb）含量分别为0、100、500和1 000 mg·kg^-1]4种处理，研究Pb胁迫对木本植物刺槐的生长生理响应特征、显微结构、Pb吸收和分布的影响。结果表明，刺槐对污染土壤中Pb具有较强的生理耐受和解毒能力。在培养初期（30 d），当土壤Pb含量为500～1 000 mg·kg^-1时，刺槐叶片过氧化物酶（POD）活性较CK显著降低41.7%～54.1%；培养60 d,Pb胁迫下刺槐叶片丙二醛（MDA）含量较CK显著提高23.6%～61.9%。然而，培养160 d，当土壤Pb含量为1 000 mg·kg^-1时，刺槐叶片的总叶绿素、MDA含量及超氧化物歧化酶、POD、过氧化氢酶活性均与CK无显著差异，且叶片维持完整的细胞结构。扫描电镜结果表明，刺槐根、茎部的导管与筛管在降低Pb向地上部运输过程中发挥着重要作用。Pb主要累积在刺槐根部，且Pb从根部向地上部的转运系数小于1。研究表明，刺槐正常的光合作用、抗氧化酶保护作用以及导管和筛管对Pb运输的阻控等过程使刺槐对Pb有较强的耐受能力，对稳定修复Pb污染土壤具有一定潜力。更多还原

【Abstract】 In this study, through a pot experiments, the effects of Pb stress on the growth, physiological response characteristics, microstructure, Pb absorption and distribution of the woody plant Robinia pseudoacacia were studied under four treatments: control（CK）, Q1, Q2, and Q3(soil Pb concentrations of 0, 100, 500, and 1 000 mg·kg^-1, respectively). The results showed that R. pseudoacacia has strong physiological tolerance and detoxification ability when exposed to Pb-contaminated soil. At the initial cultivation time（30 d）, peroxidase（POD） activity in R. pseudoacacia leaves was significantly decreased by 41.7%-54.1%, when soil Pb content was 500-1 000 mg·kg^-1. After 60 d cultivation, malondialdehyde（MDA） content in R. pseudoacacia leaves was significantly elevated by 23.6%-61.9% in response to Pb stress. However, after 160 d of cultivation, total chlorophyll, MDA content, and superoxide dismutase, POD, catalase activities in the leaves of R. pseudoacacia growing in the 1 000 mg·kg^-1 Pb-contaminated soil were only slightly changed relative to the control. Furthermore, the cells of plant leaves maintained an intact structure under Pb stress. Scanning electron microscopy indicated that the conduits and screens played an important role in inhibiting the transport of Pb from roots to shoots. Pb mainly accumulated in R. pseudoacacia roots, and the transferring coefficient of Pb from roots to shoots was less than 1. These results suggest that normal photosynthesis, antioxidant enzyme protection, and the inhibition of Pb transport by conduits and screens contribute to the strong tolerance of R. pseudoacacia to Pb stress. Therefore, this species has clear potential as a stable remediator of Pb-contaminated soil.更多还原