摘要
为揭示植物叶片对大气颗粒物的滞纳效应,本研究首次采用氧化锌(ZnO)纳米颗粒物模拟PM_(2.5)等颗粒物在欧美杨DN-2叶片表面的沉降、附着和滞留过程,利用水洗法和电感耦合等离子体质谱(ICP-MS)分别测定叶片表面和组织内的ZnO含量,通过扫描电子显微镜对叶表形貌进行观察和附着颗粒物数量统计,定量研究欧美杨对不同粒径颗粒物的吸附和吸收能力及其光合生理的响应特征。结果表明:粒径约为30 nm(NPs)、100 nm(BPs)和1μm(MPs)的3种ZnO气溶胶处理16 d后,欧美杨叶片表面对MPs的吸附质量最大,高达653.03 mg/g,显著高于NPs。而通过Image J软件统计叶表面颗粒物的数量发现,NPs处理下叶面附着颗粒物数量最多,BPs次之,MPs最少,说明颗粒物的粒径越小,分布在叶片表面的数量越多,但其在叶面附着质量较低。此外,通过对植物叶表形貌观察发现,颗粒物对气孔和角质层产生了负面影响,气孔轮廓不清晰,角质层皱折不规则。在模拟颗粒物环境中,欧美杨对粒径小于1μm颗粒物均有一定量的吸收。与吸附质量不同,欧美杨叶片对NPs的吸收量显著高于BPs和MPs,在处理16 d后高达1.17 mg/g,分别是BPs和MPs的2.59和2.89倍,这表明粒径越小的颗粒物越容易被植物吸收进入体内。NPs、BPs和MPs处理16 d后,欧美杨叶片净光合速率(P_n)分别降低了22%、44%和19%,这是由气孔和非气孔因素共同导致的。
To investigate the deposition and absorption of particulate matters on leaves,this study firstly uses the zinc oxide（ZnO）nanoparticles to simulate sedimentation,attachment and retention of fine particulate matter（PM_（2.5））on Populus deltoides×P.nigra leaves.The contents of ZnO on the leaf surface and in the leaf tissue were quantitatively determined by water-washing and inductively coupled plasma mass spectrometry（ICP-MS）,respectively.Furthermore,ZnO particle number on the leaf surface and its microstructure were analyzed by an scan electron microscope（SEM）and the response characteristics of photosynthetic physiology was also investigated by the Li-COR 6400 portable photosynthesis system.The results showed that ZnO particles could be adhered by leaves which were treated with NPs（particles with a mean diameter of 30 nm）,BPs（particles with a mean diameter of 100 nm）or MPs（particles with a mean diameter of 1μm）.The deposition capacity of Populus deltoides×P.nigra to different particles was mainly analyzed from two aspects of total quality and total particle number.The mass concentration of MPs on leaf surface was the highest after treated for 16 days,reaching 653.03 mg/g,which was significantly higher than NPs.Analyzed by Image J software,the number of particles on the foliar surface was the highest under NPs treatment,followed by BPs and MPs,indicating that the smaller the size of the particles were,the larger the number of particles distributed on the surface of the leaves,while the weight of the smaller particles was relatively lower.Moreover,P.deltoides×P.nigra could uptake particle less than 1μm.Compared with weight of deposition,the uptake of NPs by leaves was higher,reaching1.17 mg/g after 16 day treatment,which was 2.59 and 2.89 times of BPs and MPs,respectively.This indicated that the smaller size of particle was easily absorbed by plants.Phytotoxicity was tested for plants exposed to different size of ZnO aerosol.Leaf surface microstructure had obvious change,stomata was often filled with ZnO particles or was also clogged and injured cells,and slightly disturbed striations were also visible in the ZnO-treated leaves.Moreover,acute phytotoxicity was also observed in photosynthetic.After 16 days treatment of NPs,BPs and MPs,net photosynthetic rate（P_n）was reduced by 22%,44%and 19%,respectively,which was caused by stomatal and non-stomatal factors.
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2017年第4期46-54,共9页
Journal of Beijing Forestry University
基金
林业公益性行业科研专项(201304301)
“十三五”国家科技支撑计划课题(2015BAD07B01)
中国工程院咨询研究项目(2013-QTSHKJJH-01)
2014内蒙古自治区科技重大专项“内蒙古生态屏障建设林业关键技术集成与示范”
关键词
欧美杨
PM2.5
氧化锌(ZnO)颗粒物
吸收
吸附
生理特性
Populus deltoides × P.nigra
PM2.5
ZnO particle
absorption
deposition
physiological characteristics
