铝胁迫下大豆根尖细胞铝的微区分布与耐铝性分析  

Distribution of Al^(3+) in Subcellular Structure of Root Tips Cells and Aluminum Tolerance in Soybean

作　　者：俞慧娜[1] 刘鹏[1] 徐根娣[1] 蔡妙珍[1] 

机构地区：[1]浙江师范大学植物学实验室,浙江金华321004

出　　处：《作物学报》2009年第4期695-703,共9页Acta Agronomica Sinica

基　　金：国家"十一五"科技攻关计划项目(2004BA525B06);国家自然科学基金项目(30540056);浙江省自然科学基金项目(303461和304185)资助

摘　　要：以浙春3号为实验材料,利用透射电镜(TEM:Transmission Electron Microscope)-X-射线能谱(EDS:Energy Dispersive X-ray),调查铝胁迫下大豆根尖铝的微区分布及耐铝性。结果表明,Al3+胁迫导致根尖细胞细胞壁不规则加厚,线粒体数量增多,核膜膨胀,液泡中存在较多的电子致密沉淀物。90mgL-1Al3+处理的根尖细胞内含物完全降解消失,仅剩细胞壁。10mgL-1Al3+处理的线粒体、细胞壁和液泡电子致密沉淀物中均检测到Al;随着Al3+处理浓度的增大,各细胞器中Al的质量和原子数百分比逐渐增大。线粒体在60mgL-1和90mgL-1Al3+处理下,液泡电子致密沉淀物在90mgL-1Al3+处理下,均未被检测出Al。在60mgL-1Al3+处理下唯一一次在细胞核中检测到Al。Al3+抑制了根系生长,根系细胞中细胞壁的Al3+含量受影响最明显。P/Al在细胞壁和线粒体中的相对原子数随Al3+浓度的增大而下降。研究结果表明X-射线能谱对铝在亚显微结构上的定位是一种快速、有效的方法。铝最先积累在细胞壁上,随Al3+处理浓度增大逐渐积累于部分细胞器和细胞核中,且含量在细胞中的分布亦由外向里呈递减趋势。Aluminum （Al） toxicity is a major limiting factor for yield and quality in crop production in acid soil. Micromolar concentrations of Al^3＋ may inhibit root elongation and consequently influence water and nutrient uptake, resulting in poor plant growth. The microanalysis of the elements was conducted on Zhechun 3 by using Transmission Electron Microscope （TEM） and Energy Dispersive X-ray （EDS） to examine the distribution of Al^3＋ in root tips and Al resistance of soybean. We found that Al^3＋ stresses resulted in irregularly thickened cell wall, increased number of mitochondria, expanded nuclear membrane, and densified precipitates of vacuole. Under the highest Al^3＋ concentration, the mitochondria and other organelles disappeared but cell wall. We detected Al in cell wall, mitochondria and electron-dense precipitates of vacuole of root tip cell under the 10 mg L^-1 Al^3＋ stresses by EDS. With the increase of external Al^3＋ concentration treated, the weight and atomic percentage of Al in the organelles increased. The Al^3＋ was found in nuclei when the external Al^3＋ was over 60 mg L^-1. And there was no Al^3＋ in mitochondrion under 60 mg L^-1 and 90 mg L^-1 Al^3＋ treatments and electron-dense precipitates of vacuole under the 90 mg L^-1 Al^3＋ stresses. The 14 days Al^3＋ stresses significantly inhibited the growth of root system. The content of Al^3＋ in cell wall was most significantly impacted by the external Al^3＋ concentration. The atomic number of P/Al in cell wall and mitochondria decreased with increased Al^3＋ content. EDS can be used to determine the subcellular location of Al^3＋. As the treatment concentrations of Al^3＋ increased, Al^3＋ primarily accumulated in the cell wall, gradually gathered in part of the organelles and nuclei. The Al^3＋ concentrations also decreased from out layer to insider in the cell.

关 键 词：铝胁迫 大豆 根尖细胞 透射电镜-X-射线能谱分析 根系生长 

分 类 号：S565.1[农业科学—作物学]