In recent years, transgenic hairy root tissue is widely used in the phytoremediation research of heavy metals and organic pollutants,and it has become a convenient model to investigate the toxic response mechanism of pollutants in the laboratory. To explore the response differences among SolanumnigrumL., BrassicacampestrisL. and Brassica juncea under Cd stress, the growth status, the ability of enriching Cd, cell apoptosis and antioxidant enzyme activities of hairy roots with three Cd hyperaccumulators were measured. The results showed that when Cd concentration was 0-50 μmol·L-1 , three hyperaccumulators hairy roots were hardly affected by the toxicity of Cd, and when Cd concentration reached 75-100 μmol·L-1 , three hyperaccumulators hairy roots exhibited defensive re-sponse to resist the toxicity of Cd. Under 100 μmol·L-1 of Cd concentration, the biomass of Solanum nigrum L. hairy roots was less influenced, followed by Brassicajunceahairy roots, then the BrassicacampestrisL. hairy roots. SolanumnigrumL. hairy roots had the best ability (745.0 μg·g-1) of Cd enrichment, followed by Brassicajuncea hairy roots (681.4μg·g-1), and BrassicacampestrisL. had a lowest Cd enrichment ability (505.2μg·g-1) under 100μmol·L-1 of Cd concentration. Furthermore, levels of cell apoptosis all increased with the rise of Cd concentrations for three hairy roots under Cd stress, and the apoptosis level of Solanum nigrum L. hairy roots was lower than those of Brassica campestris L. and Brassica juncea hairy roots under 100 μmol·L-1 of Cd concentration. At the same time, there is a little difference among activities of antioxidant enzyme of three hairy roots under different concentrations of Cd stress. From the above results, SolanumnigrumL. hairy roots have the best resistance for Cd toxicity and the best capacity of Cd enrichment, so these hairy roots can be used as a laboratory research vector for the development of transgenic Cd hyperaccumulators.%近年来,转基因毛状根组织被越来越多地应用于重金属和有机污染物的植物修复技术研究中,已成为进行污染物毒性响应机制研究的便捷的实验室工具.为了探究龙葵、油菜、芥菜3种镉(cadmium,Cd)超富集植物对Cd毒性胁迫响应的差异,以诱导出的3种植物毛状根为研究材料,从毛状根的生长状态、富集Cd的能力、根组织细胞的凋亡程度和抗氧化酶活性等方面进行了探讨.结果表明:Cd浓度为0~50μmol·L-1时,龙葵、油菜、芥菜毛状根受Cd毒害的影响都不明显;Cd浓度为75~100μmol·L-1时,龙葵、油菜、芥菜毛状根均表现出对Cd胁迫的防御响应.在较高的Cd浓度(100μmol·L-1)下,龙葵毛状根的生物量受Cd毒害的影响最小,芥菜次之,油菜受影响最大;同时龙葵毛状根富集的Cd含量最高(745.0μg·g-1),芥菜次之(681.4μg·g-1),油菜最差(505.2μg·g-1).龙葵、油菜、芥菜毛状根在Cd胁迫下的细胞凋亡水平均随Cd浓度的升高而升高,当Cd浓度为100μmol·L-1时,龙葵毛状根比油菜和芥菜毛状根的细胞凋亡程度均低.同时3种植物毛状根在不同浓度Cd处理下抗氧化酶活性的变化有一定差异.从上述结果综合来看,龙葵毛状根受Cd毒害的影响最小、富集Cd的能力最好,是进一步开展Cd超富集植物转基因改造研究的较好的实验室载体.
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