Cadmium tolerance in six poplar species
Cadmium tolerance in six poplar species
复制标题
六种杨树的镉耐受性
DOI：
10.1007/s11356-012-1008-8
复制
发表时间：
2013-01-01
影响因子：
5.8
通讯作者：
Luo, Zhi-Bin
中科院分区：
文献类型：
--
作者：
He, Jiali;Ma, Chaofeng;Luo, Zhi-Bin
筛选出对Cd具有较强耐受性的白杨品种，并研究其耐受Cd的生理机制，是杨树应用于植物修复的关键。本研究旨在探讨6种白杨对镉的耐性差异及其生理机制。用0和200 μM的CdSO_4处理20天后，对6种杨树的扦插苗进行10周的培养。用便携式光合作用测定系统测定了成熟叶片的气体交换。采用火焰原子吸收分光光度法测定组织中镉的含量。计算了Cd的生物富集系数（BCF）和转运系数（Tf）。采用比色法分析组织中的非酶化合物和抗氧化酶活性。Cd暴露导致青杨（Populus cathayana（Zhonghua 1））等4种白杨光合作用下降。在6种植物中，中华杨（中华1号）的组织Cd含量最高，地上部分Cd含量最高，地上部分生物富集系数最高，Cd暴露量最低。在Cd胁迫下，根、木、叶中可溶性总糖含量增加，淀粉含量减少。结果表明，P处理能诱导根和叶中O2·−和H2O2的产生，增加游离脯氨酸、可溶性酚类物质和抗氧化酶的活性。中华1号（cathayana（zhonghua 1））根据盆栽试验结果，得出了P.中华1号（cathayana（zhonghua 1））对Cd的植物修复能力上级其它5种植物，其在Cd胁迫下的生理变化协调性好，具有较强的Cd耐性。
Selection of poplar species with greater Cd tolerance and exploiting the physiological mechanisms involved in Cd tolerance are crucial for application of these species to phyto-remediation. The aim of this study is to investigate variation in Cd tolerance among the six poplar species and its underlying physiological mechanisms. Cuttings of sixPopulusspecies were cultivated for 10 weeks before exposure to either 0 or 200 μM CdSO4for 20 days. Gas exchange in mature leaves was determined by a portable photosynthesis system. Cd concentrations in tissues were analyzed by a flame atomic absorbance spectrometry. Subsequently, Cd amount per plant, bio-concentration factor (BCF) and translocation factor (Tf) were calculated. Nonenzymatic compounds and activities of antioxidative enzymes in tissues were analyzed spectrophotometrically. Cd exposure caused decline in photosynthesis in four poplar species includingPopulus cathayana(zhonghua 1). Among the six species,P. cathayana(zhonghua 1) displayed the highest Cd concentrations in tissues, the largest Cd amount in aerial parts, the highest BCF in aerial parts andTfunder Cd exposure. Under Cd stress, increases in total soluble sugars in roots but decreases in starch in roots, wood, and leaves ofP. cathayana(zhonghua 1) were found. Induced O2•−and H2O2production in roots and leaves, and increases in free proline, soluble phenolics, and activities of antioxidative enzymes were observed inP. cathayana(zhonghua 1). Based on results of this pot experiment, it is concluded thatP. cathayana(zhonghua 1) is superior to other five species for Cd phyto-remediation, and its well-coordinated physiological changes under Cd exposure confer the great Cd tolerance of this species.