ABSTRACT

Nasturtium officinale is a cadmium (Cd) accumulator plant, but its phytoremediation capacity is low compared to other hyperaccumulators. To improve the phytoremediation capacity, the seedlings of N. officinale was grown in Cd-contaminated paddy soils, and the effects of diethyl aminoethyl hexanoate (DA-6) on N. officinale growth and Cd accumulation were studied. DA-6 increased the shoot biomass of N. officinale, and had a quadratic polynomial regression relationship with root and shoot biomass. DA-6 had no significant effects on chlorophyll a, chlorophyll b, and carotenoid contents, increased peroxidase, superoxide dismutase, and catalase activities, and decreased the soluble protein content. DA-6 also increased the Cd content and Cd extraction of N. officinale to some extent, and had a quadratic polynomial regression relationship with the root Cd content, shoot Cd content, root Cd extraction, and shoot Cd extraction. Significant correlations were found among plant biomass, chlorophyll content, Cd content, Cd extraction, and antioxidant enzyme activity. Furthermore, soluble protein content and soil exchangeable Cd was significantly correlated with plant Cd content and Cd extraction. Therefore, DA-6 can promote N. officinale growth and improve its phytoremediation capacity for Cd-contaminated paddy soils, with a recommend optimum dose of 20 mg/L.

摘要

金莲花是一种镉 (Cd) 富集植物，但与其他超富集植物相比，其植物修复能力较低。为提高植物修复能力，在镉污染的稻田中培育铁皮油菜幼苗，研究了氨乙基己酸二乙酯（DA-6）对铁皮油菜生长和镉积累的影响。DA-6增加了铁皮的地上部生物量，并且与根和地上部生物量呈二次多项式回归关系。DA-6对叶绿素a、叶绿素b无显着影响和类胡萝卜素含量，过氧化物酶、超氧化物歧化酶和过氧化氢酶活性增加，可溶性蛋白含量降低。DA-6也一定程度上提高了铁皮的Cd含量和Cd提取量，与根Cd含量、枝条Cd含量、根部Cd提取量、枝条Cd提取量呈二次多项式回归关系。植物生物量、叶绿素含量、镉含量、镉提取量和抗氧化酶活性之间存在显着相关性。此外，可溶性蛋白质含量和土壤交换性Cd与植物Cd含量和Cd提取量显着相关。因此，DA-6可以促进N. officinale生长和提高其对镉污染稻田土壤的植物修复能力，推荐的最佳剂量为 20 mg/L。