Guangdong Ecological Meteorology Center, Guangzhou 510080, PR China.
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, PR China.
Sci Rep. 2017 Jan 11;7:40583. doi: 10.1038/srep40583.
A pot experiment was conducted to investigate the effects of calcium silicate (CS) on the subcellular distribution and chemical forms of cadmium (Cd) in grain amaranths (Amaranthus hypochondriacus L. Cv. 'K112') grown in a Cd contaminated soil. Results showed that the dry weight and the photosynthetic pigments contents in grain amaranths increased significantly with the increasing doses of CS treatments, with the highest value found for the treatment of CS3 (1.65 g/kg). Compared with the control, application of CS4 (3.31 g/kg) significantly reduced Cd concentrations in the roots, stems and leaves of grain amaranths by 68%, 87% and 89%, respectively. At subcellular level, CS treatment resulted in redistribution of Cd, higher percentages of Cd in the chloroplast and soluble fractions in leaves of grain amaranths were found, while lower proportions of Cd were located at the cell wall of the leaves. The application of CS enhanced the proportions of pectate and protein integrated forms of Cd and decreased the percentages of water soluble Cd potentially associated with toxicity in grain amaranths. Changes of free Cd ions into inactive forms sequestered in subcellular compartments may indicate an important mechanism of CS for alleviating Cd toxicity and accumulation in plants.
采用盆栽试验研究了硅钙肥（CS）对 Cd 污染土壤上种植的籽粒苋（Amaranthus hypochondriacus L. Cv. 'K112'）亚细胞分布和化学形态的影响。结果表明，随着 CS 处理剂量的增加，籽粒苋的干重和光合色素含量显著增加，CS3（1.65 g/kg）处理的含量最高。与对照相比，CS4（3.31 g/kg）处理可使籽粒苋根、茎和叶中的 Cd 浓度分别降低 68%、87%和 89%。在亚细胞水平上，CS 处理导致 Cd 的再分配，发现籽粒苋叶片中的 Cd 更多地分布在叶绿体和可溶部分，而叶片细胞壁中的 Cd 比例较低。CS 的施用增加了果胶和蛋白整合态 Cd 的比例，降低了与毒性相关的水溶态 Cd 的比例。将游离的 Cd 离子转化为亚细胞区室中无活性的形式可能是 CS 缓解 Cd 毒性和在植物中积累的一个重要机制。
