• 研究报告 •

### 欧美杨对PM2.5中重金属铅的吸附、吸收及适应性变化

1. (北京林业大学生物科学与技术学院， 北京 100083)
• 出版日期:2015-12-10 发布日期:2015-12-10

### Adhesion and absorption of Pb in PM2.5 and adaptative changes in Populus euramericana ‘Neva’.

CAO Xue-hui, AN Hai-long, LIU Qing-qian, LIU Chao, GUO Hui-hong, YIN Wei-lun, XIA Xin-li**

1. (College of Biological Science and Technology, Beijing Forestry University, Beijing 100083, China)
• Online:2015-12-10 Published:2015-12-10

Abstract: Lead (Pb) pollution caused by PM2.5 is becoming increasingly serious. In this study, PM2.5 particles were generated by aerosol generator to simulate different Pb pollution levels. The adhesion, absorption and transportation of PM2.5Pb by leaves of Populus euramericana ‘Neva’ seedlings were studied. The changes of stomata and physiological characteristics in P. euramericana leaves were also investigated. The results showed that Pbcontaining particles can be adhered by the leaves, and the number of Pbcontaining particles on leaves was higher under the severe than the low pollution treatment. The content of Pb was the highest in leaves, while lower in stems and roots under both the low and severe pollution treatments. However, there were some differences in the transportations of Pb from leaves to stems and roots between the two treatments. In the low pollution treatment, Pb was transported from leaves to stems and roots 3 and 7 days after the treatment, respectively. By contrast, Pb in leaves was transported to roots only 3 days after the severe pollution treatment. Ultramicroscopic observation indicated that Pbcontaining particles first appeared in the cell wall of leaf epidermal cells, and was then transported to mesophyll cells through apoplast. In the mesophyll cells, Pbcontaining particles were mainly distributed in cell wall and cytoplasm, with a few particles observed in vacuole. The stomatal aperture, MDA and proline content, and SOD activity in P. euramericana leaves exhibited adaptive changes with the extension of time under both low and severe Pb pollution treatments. Our results demonstrate that Pb in PM2.5 particles could be adhered and absorbed by the leaves of P. euramericana, and P. euramericana can adapt to Pb pollution through decreasing stomatal aperture, osmotic adjustment and increasing oxidation resistance.