Department of Environmental Sciences and Engineering, Government College University, Allama Iqbal Road, Faisalabad, 38000, Pakistan.
Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, Pakistan.
Environ Sci Pollut Res Int. 2017 Sep;24(27):21938-21947. doi: 10.1007/s11356-017-9860-1. Epub 2017 Aug 6.
Cadmium (Cd) contamination of farmland soils is a widespread problem around the globe, and rice (Oryza sativa L.) tends to accumulate more Cd and is considered as one of the major sources of Cd intake in humans, especially consuming rice-derived products. The current study investigated the effects of foliar applied aspartic acid (Asp) on growth parameters, biomass, chlorophyll concentration, gas exchange characteristics, Cd uptake, and antioxidative capacity in the shoots and roots of rice seedlings exposed to Cd stress. For this, 30-day-old rice nursery was transferred in the soil with aged Cd contamination (2.86 mg kg). After 2 weeks of growth, different concentrations (0, 10, 15, and 20 mg L) of Asp were foliar applied four times with a 7-day interval, and the crop was harvested after 10 weeks of transplanting. Foliar applied Asp increased the plant height, shoot and root dry weight, chlorophyll concentration, and gas exchange parameters, while it reduced the Cd concentrations in both shoots and roots as well as shoot to root Cd translocation factor compared to the control. Foliar application of Asp reduced the malondialdehyde content and electrolyte leakage in rice parts compared to the control in a dose-additive manner. The activities of key antioxidant enzymes increased while peroxidase activity decreased by exogenous Asp. The increase in plant weight and photosynthesis might be due to lower Cd concentrations in plants which may reduce the oxidative stress and also help the plants to minimize direct damage caused by Cd to the photosynthetic organs.
农田土壤中的镉（Cd）污染是一个全球性的问题，而水稻（Oryza sativa L.）往往会积累更多的 Cd，被认为是人类摄入 Cd 的主要来源之一，尤其是食用源于水稻的产品。本研究调查了叶面喷施天门冬氨酸（Asp）对 Cd 胁迫下水稻幼苗生长参数、生物量、叶绿素浓度、气体交换特性、Cd 吸收和抗氧化能力的影响。为此，将 30 天大的水稻幼苗移栽到受 Cd 污染（2.86 mg kg）的土壤中。生长 2 周后，每隔 7 天叶面喷施 4 次不同浓度（0、10、15 和 20 mg L）的 Asp，移栽后 10 周收获作物。与对照相比，叶面喷施 Asp 增加了株高、地上部和地下部干重、叶绿素浓度和气体交换参数，同时降低了地上部和地下部的 Cd 浓度以及地上部与地下部 Cd 转运系数。与对照相比，叶面喷施 Asp 以剂量累加的方式降低了水稻各部位的丙二醛含量和电解质渗漏。外源性 Asp 增加了关键抗氧化酶的活性，降低了过氧化物酶的活性。植物重量和光合作用的增加可能是由于植物中 Cd 浓度降低，这可能减轻了氧化应激，也有助于植物将 Cd 对光合器官的直接损伤降到最低。
