Tao Yi-Ming, Chen Yan-Zhen, Liang Yang-Lin, Xu Mei-Yan, Xu Xiang-Ming
College of Life Sciences, Guangxi Normal University, Guilin 541004, China.
Zhi Wu Sheng Li Yu Fen Zi Sheng Wu Xue Xue Bao. 2007 Aug;33(4):301-8.
Jerusalem artichoke (Helianthus tuberosus L.) seedlings cultured in sandy media were treated with Hoagland nutrition solution with different concentrations of Cd(NO(3))(2) from 0 to 400 micromol/L. After 50 days' treatment, Cd accumulation, activities of peroxidase (POD, EC 1.11.1.7), superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6) were measured and electrophoretograms of POD isoenzymes were analyzed. The accumulation of Cd in seedlings increased from Cd 50-100 micromol/L, after which further increases in Cd concentration resulted in only small increases in accumulation of Cd in seedlings. MDA content was markedly higher than control values indicating the enhanced membrane lipid peroxidation in roots and leaves. POD activities in leaf and root extracts increased with an increase of Cd concentration from 0 to 50 and 100 micromol/L and then decreased with further increases to 200 and 400 micromol/L. Under moderate Cd level of 50-200 micromol/L, SOD activities in leaf and root extracts increased whereas with a higher Cd level of 400 micromol/L marked inhibitions in enzyme activities were observed. With increase in Cd concentration marked elevations in CAT activities in leaves and roots were observed. Results of electrophoresis show that the alteration of POD isoenzyme was noticeable to Cd and an additional POD isoenzyme LP10 appeared. It is suggested that POD isoenzyme of Jerusalem artichoke seedlings could be used as bioindicator for soil contamination by Cd.
将沙培的菊芋（Helianthus tuberosus L.）幼苗用浓度为0至400 μmol/L的不同浓度Cd(NO₃)₂的Hoagland营养液处理。处理50天后，测定镉积累量、过氧化物酶（POD，EC 1.11.1.7）、超氧化物歧化酶（SOD，EC 1.15.1.1）、过氧化氢酶（CAT，EC 1.11.1.6）的活性，并分析POD同工酶的电泳图谱。幼苗中镉的积累量在Cd浓度为50 - 100 μmol/L时增加，此后镉浓度进一步升高，幼苗中镉的积累量仅小幅增加。丙二醛（MDA）含量明显高于对照值，表明根和叶中的膜脂过氧化作用增强。叶和根提取物中的POD活性随着镉浓度从0增加到50和100 μmol/L而增加，然后随着镉浓度进一步增加到200和400 μmol/L而降低。在50 - 200 μmol/L的中度镉水平下，叶和根提取物中的SOD活性增加，而在400 μmol/L的较高镉水平下，观察到酶活性受到明显抑制。随着镉浓度的增加，叶和根中的CAT活性明显升高。电泳结果表明，POD同工酶对镉的变化明显，并且出现了一种额外的POD同工酶LP10。表明菊芋幼苗的POD同工酶可作为镉污染土壤的生物指示物。
