Arsenic (As) and cadmium (Cd) are ubiquitous in the environment and they are both toxic to humans. When present in soils, they can enter food chain, thereby threatening human health. Water spinach (Ipomoea aquatica) is an important leafy vegetable, which is widely consumed in Asian countries. However, it is efficient in taking up As and Cd from soils and accumulating them in the edible parts. Therefore, it is of significance to reduce its As and Cd content, especially in contaminated soil. In this study, pot experiments were conducted to investigate the ability of As-hyperaccumulator Pteris vittata in reducing As and Cd uptake by water spinach under different phosphorus treatments. P. vittata was grown for 60 d in a contaminated-soil amended with P fertilizer (+P) or phosphate rock (+PR), followed by water spinach cultivation for another 30 d. Plant biomass, As and Cd contents in plants and soils, and soil pH were analyzed. We found that, P. vittata coupled with PR decreased the As concentration in water spinach shoots by 42%, probably due to As uptake by P. vittata. Moreover, P. vittata decreased the Cd accumulation in water spinach by 24-44%, probably due to pH increase of 0.47-0.61 after P. vittata cultivation. Taking together, the results showed that P. vittata coupled with PR decreased the As and Cd content in water spinach, which is of significance for improving food safety and protecting human health.

中文翻译：

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凤尾蕨与磷酸盐岩结合可有效减少水菠菜从污染土壤中吸收砷和镉。

砷（As）和镉（Cd）在环境中无处不在，并且它们都对人类有毒。当存在于土壤中时，它们会进入食物链，从而威胁人类健康。菠菜（Ipomoea aquatica）是一种重要的多叶蔬菜，在亚洲国家被广泛食用。但是，从土壤中吸收砷和镉并将其积累在可食部分是有效的。因此，降低砷和镉的含量具有重要意义，尤其是在污染土壤中。在这项研究中，进行了盆栽试验，以研究不同磷处理条件下的超级富集凤尾蕨减少水菠菜吸收As和Cd的能力。紫青假单胞菌在用P肥料（+ P）或磷矿（+ PR）改良的污染土壤中生长60 d，然后再进行水菠菜培养30 d。分析了植物和土壤中的植物生物量，As和Cd含量以及土壤pH值。我们发现，P。vittata与PR结合可使水菠菜芽中的As浓度降低42％，这可能是由于P. vittata吸收了As。此外，P。vittata降低了菠菜中Cd的积累24-44％，这可能是由于P. vittata培养后pH值增加了0.47-0.61所致。综上所述，结果表明，白菜假单胞菌与PR结合可降低菠菜中As和Cd的含量，对提高食品安全性和保护人体健康具有重要意义。菠菜使菠菜中Cd的积累减少了24-44％，这可能是由于豌豆栽培后pH值增加了0.47-0.61。综上所述，结果表明，白菜假单胞菌与PR结合可降低菠菜中As和Cd的含量，对提高食品安全性和保护人体健康具有重要意义。菠菜使菠菜中Cd的积累减少了24-44％，这可能是由于豌豆栽培后pH值增加了0.47-0.61。综上所述，结果表明，白菜假单胞菌与PR结合可降低菠菜中As和Cd的含量，对提高食品安全性和保护人体健康具有重要意义。