College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, Guangdong Provincial Engineering and Technology Research Center for Environmental Risk Prevention and Emergency Disposal, School of Environment and Energy, South China University of Technology, Guangzhou, Guangdong, 510006, China.
Environ Pollut. 2020 Jun;261:114213. doi: 10.1016/j.envpol.2020.114213. Epub 2020 Feb 22.
Brassica juncea L. is an attractive species in PTMs contaminated soil remediation ascribing to its high tolerance under stress and great accumulation capacity of metals. To identify the potential Cd/Zn accumulators from numerous different Chinese mustard cultivars for practical phytoremediation is a promising strategy in China. In present work, a pot experiment involving elevated Cd/Zn concentrations was performed among 21 cultivars. Regarding physiological and biochemical indicators under Cd/Zn stress, principal component analysis and cluster analysis were used for cultivar tolerance evaluation and classification. Results showed that BJ (Bao Jie, var. involutus) cultivar was distinguished as a potential phytoremediation candidate comparing with other cultivars. Moreover, BJ accumulated the maximum Cd content of 63.85 and 77.29 mg kg DW in shoots and roots, respectively, and the maximum Zn uptake by BJ were 6693 and 4777 mg kg DW in shoots and roots, respectively. Accordingly, BJ had the highest Cd/Zn tolerance, remarkable accumulation and translocation capacity (accumulation factor (AF) > 1 for Cd and Zn; translocation factor (TF) > 0.8 for Cd and TF > 1 for Zn). In addition, the superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities of the mustard increased initially under low Cd/Zn stress as compared to the control and then declined dramatically with the increasing metals exposure concentration. Therefore, the antioxidant enzymes may play a protective role against reactive oxygen species (ROS) under low Cd/Zn stress, whereas the defense system might be collapsed under relatively high Cd/Zn stress. Furthermore, the enhanced Cd/Zn exposure led to an increase in malondialdehyde (MDA) content in the mustard cultivars, indicating that Cd/Zn had induced more severe oxidative stress and higher degree of lipid peroxidation had occurred. The present investigation results indicated that BJ (Bao Jie, var. involutus), as a native cultivar, can be further applied in the field trials of phytoremediation practices in contaminated soil.
芥菜（Brassica juncea L.）是一种在 PTMs 污染土壤修复中很有吸引力的物种，因为它在压力下具有很高的耐受性和对金属的强积累能力。在中国，从众多不同的芥菜品种中筛选出潜在的 Cd/Zn 积累品种，是一种很有前途的植物修复策略。本研究在 21 个品种中进行了盆栽实验，涉及提高 Cd/Zn 浓度。对于 Cd/Zn 胁迫下的生理生化指标，采用主成分分析和聚类分析对品种的耐受性进行评价和分类。结果表明，与其他品种相比，BJ（Bao Jie，var. involutus）品种被认为是一种潜在的植物修复候选品种。此外，BJ 在地上部分和根部分别积累了最大的 Cd 含量 63.85 和 77.29 mg kg DW，在地上部分和根部分别吸收了最大的 Zn 量 6693 和 4777 mg kg DW。因此，BJ 具有最高的 Cd/Zn 耐受性、显著的积累和转运能力（Cd 和 Zn 的积累因子（AF）>1；Cd 和 Zn 的转运因子（TF）>0.8）。此外，与对照相比，芥菜在低 Cd/Zn 胁迫下，超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性最初增加，然后随着金属暴露浓度的增加而急剧下降。因此，抗氧化酶在低 Cd/Zn 胁迫下可能对活性氧（ROS）发挥保护作用，而在相对高 Cd/Zn 胁迫下，防御系统可能崩溃。此外，增强的 Cd/Zn 暴露导致芥菜品种中丙二醛（MDA）含量增加，表明 Cd/Zn 诱导了更严重的氧化应激，发生了更高程度的脂质过氧化。本研究结果表明，BJ（Bao Jie，var. involutus）作为一种本地品种，可以进一步应用于污染土壤的植物修复田间试验。
