Guangdong Industrial Contaminated Site Remediation Technology and Equipment Engineering Research Center, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, People's Republic of China.
Department of Geography, Florida State University, Tallahassee, FL, 32306, USA.
Environ Sci Pollut Res Int. 2021 Mar;28(11):14041-14053. doi: 10.1007/s11356-020-11569-3. Epub 2020 Nov 17.
In this study, cadmium (Cd) solution spraying and Cd-contaminated soil pot experiments were conducted to investigate the influence of Cd from atmospheric deposition and soil on the growth, cumulative distribution, chemical morphology, physiological, and biochemical responses of Amaranthus tricolor L. The results indicated that Cd in plants mainly came from soil (92-98%) and was stored in the roots in large quantities while the portion from atmospheric deposition could also effectively increase Cd content in stems and leaves (2-3%). Cd was mainly stored in plant cell walls and would transfer to the soluble part under high-concentration soil stress Cd from atmospheric deposition alone promoted the growth of plants, but high Cd concentrations from soil had the negative influence. The contents of HO and MDA in plants increased under soil and atmospheric Cd stress, indicating that the plant cells were damaged by oxidative stress. The content of antioxidant enzymes such as POD, CAT, SOD, and antioxidants like AsA and GSH increased under low-concentration Cd stress but decreased under elevated stress, suggesting that high Cd-contaminated soil poses severe toxicity on the antioxidant system of the plants. Hence, the accumulation and physiological response of plants under multi-source Cd contamination were mainly affected by high soil Cd concentrations. Though the effect of atmospheric deposition is relatively less, it cannot be ignored.
在这项研究中，通过向植物喷洒含镉溶液和在受污染的土壤中进行盆栽实验，研究了大气沉降和土壤中的镉对苋菜生长、累积分布、化学形态、生理生化响应的影响。结果表明，植物中的镉主要来自土壤（92-98%），大量储存在根部，而大气沉降也可以有效地增加茎和叶中的镉含量（2-3%）。镉主要储存在植物细胞壁中，在高浓度土壤胁迫下会转移到可溶性部分。单独来自大气沉降的镉促进了植物的生长，但高浓度的土壤镉则有负面影响。在土壤和大气镉胁迫下，植物体内的 HO 和 MDA 含量增加，表明植物细胞受到氧化应激的破坏。在低浓度镉胁迫下，POD、CAT、SOD 等抗氧化酶和 AsA、GSH 等抗氧化剂的含量增加，但在高浓度胁迫下则减少，表明高浓度镉污染土壤对植物抗氧化系统具有严重毒性。因此，植物在多源镉污染下的积累和生理响应主要受高土壤镉浓度的影响。虽然大气沉降的影响相对较小，但也不能忽视。
