Plant Ecology and Environmental Science Division, CSIR-National Botanical Research Institute, Lucknow, 226001, India.
Deen Dayal Upadhyaya Gorakhpur University, Gorakhpur, 273009, India.
Environ Sci Pollut Res Int. 2020 Jul;27(19):24025-24038. doi: 10.1007/s11356-020-08663-x. Epub 2020 Apr 17.
Arsenic (As), a toxic metalloid, is finding its route to human through intake of As-contaminated water and consumption of food grown on contaminated soil. Rice is the most As-affected crop. Present study is aimed to assess the impact of stabilized orthosilicic acid (a proprietary formulation for plant-available silicon (Si) and earlier used as fertilizer for rice to enhance growth and yield) in reducing the accumulation of As in rice grains. Application of arsenic in the form of arsenate (As) and arsenite (As) significantly affected plant growth in a dose-dependent manner. Higher doses of As and As (50 and 25 mg L respectively) significantly decreased the yield attributes leading to lower yield. A significant accumulation of As in grain was observed in both As- and As-exposed plants in a dose-dependent manner. Arsenic exposure also increased the level of Si in rice grains. Application of Si, either in soil or on leaves (foliar), greatly reduced grain As accumulation (up to 67% in As and 78% in As) and enhanced the growth and yield of plants under As stress. The level of thiols and activities of antioxidant enzymes were also enhanced under Si application. Foliar Si application was more effective in increasing grain Si level and reducing grain As than soil Si. The level of other trace elements was also significantly enhanced by Si application irrespective of the presence or absence of As in comparison with control. Arsenic exposure constrained some of the trace elements, such as Zn and Co, which were restored by Si application. Results of the present study showed that the application of currently used Si formulation may effectively reduce grain As level even in highly As-contaminated soil and improve grain quality of rice.
砷（As）是一种有毒的类金属，通过摄入受污染的水和食用受污染土壤种植的食物进入人体。水稻是受砷影响最大的作物。本研究旨在评估稳定的正硅酸（一种专有的植物可用硅（Si）配方，以前曾用作水稻肥料以促进生长和产量）在减少水稻籽粒中砷积累方面的作用。砷以砷酸盐（As）和亚砷酸盐（As）的形式施入会以剂量依赖的方式显著影响植物生长。较高剂量的 As 和 As（分别为 50 和 25 mg L）显著降低了产量性状，导致产量降低。在 As 和 As 暴露的植物中均观察到砷在籽粒中的积累呈剂量依赖性增加。砷暴露还增加了水稻籽粒中的硅水平。Si 的应用，无论是在土壤中还是在叶片上（叶面），都大大减少了籽粒中的砷积累（As 减少 67%，As 减少 78%），并增强了在砷胁迫下植物的生长和产量。在 Si 应用下，巯基水平和抗氧化酶活性也得到增强。叶面 Si 应用比土壤 Si 更有效地提高籽粒 Si 水平和降低籽粒 As。与对照相比，无论是否存在 As，Si 的应用都会显著提高其他微量元素的水平。砷暴露限制了一些微量元素，如 Zn 和 Co，而 Si 的应用则恢复了这些微量元素。本研究的结果表明，即使在高度受砷污染的土壤中，目前使用的 Si 配方的应用也可能有效地降低籽粒中的砷含量，从而提高稻米的品质。
