铅胁迫对毛白杨组培生根苗生理生化及根尖细胞微管骨架的影响  

EFFECTS OF LEAD STRESS ON BIOCHEMICAL CHARACTERISTICS AND MICROTUBULE CYTOSKELETON ORGANIZATION OF TISSUE CULTURE SEEDLINGS OF Populus tomentosa

作　　者：余洋[1] 安新民[1] 郝瑞芝[1] 武佳叶[1] 荆艳萍[1] 

机构地区：[1]北京林业大学林木育种国家工程实验室/林木花卉遗传育种教育部重点实验室国家林业局树木花卉育种与生物工程重点开放实验室,北京100083

出　　处：《核农学报》2011年第6期1268-1273,共6页Journal of Nuclear Agricultural Sciences

基　　金：国家林业公益性项目(No.201004009)

摘　　要：用50μmol/L硝酸铅对毛白杨组培生根苗进行不同时间的处理,测定叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)4种抗氧化酶活性水平和丙二醛(MDA)含量的变化;并通过间接免疫荧光染色法观察根尖分生区细胞的微管骨架。结果显示:铅能使毛白杨叶片APX和POD活性出现先增加后下降的变化趋势,但不能刺激CAT和SOD活性的显著增加;长时间的铅处理能抑制4种酶的活性并导致脂质过氧化程度加剧。铅胁迫导致毛白杨根尖细胞微管骨架发生异常,主要体现在周质微管发生扭曲倾斜分布,纺锤体极发生偏转,细胞分裂面的方向在毛白杨根尖细胞中发生改变。研究表明毛白杨组培生根苗抗氧化系统中APX和POD响应铅胁迫并起主要防御作用,其根尖细胞微管骨架参与了对铅胁迫的初始应答过程。The tissue culture seedlings of Populus tomentosa were exposed to lead of 50μmol/L for different treatment times.Biochemical characteristics were determined including superoxide dismutase（SOD）,peroxidase（POD）,catalase（CAT）,ascorbate peroxidase（APX） activities and malondialdehyde（MDA） of leaves and the microtubule organization in the root tip cells of the tissue culture seedlings.Results revealed that activities of APX and POD increased first and then decreased with extension of the exposure time,while SOD and CAT activities did not show any obvious changes.Long time Pb treatment inhibited the activities of all four enzymes and caused lipid peroxidation in the leaves exacerbated.Pb disturbed microtubule structure in interphase and mitotic cells and induced aberrations such as loss of transverse organization of cortical microtubules in their orientation,deflection of the mitotic spindle and abnormal direction of cell division in the root tip cells.These results suggested that,in the antioxidant systems of the tissue culture seedlings of P.tomentosa,SOD and APX play more important roles in Pb resistance,and microtubules in the root tip cells are involved in the responses to lead stress.

关 键 词：毛白杨 铅 微管骨架 抗氧化酶 

分 类 号：S792.11[农业科学—林木遗传育种]