Arsenic accumulation and metabolism in rice (Oryza sativa L.)
Arsenic accumulation and metabolism in rice (Oryza sativa L.)
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DOI：
10.1021/es0101678
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发表时间：
2002-03-01
影响因子：
11.4
通讯作者：
Cotter-Howells, J
中科院分区：
文献类型：
--
作者：
Abedin, MJ;Cresser, MS;Cotter-Howells, J
在孟加拉国、西孟加拉（印度）和其他地方，由于使用受砷污染的地下水灌溉农作物，导致农业土壤中的砷浓度升高。水稻（Oryza sativa L.）是孟加拉国受砷污染地区种植的主要农作物。因此，人们担心砷在这些土壤中种植的水稻中的积累。通过温室试验研究了砷污染灌溉水对水稻生长、砷吸收和形态分布的影响。温室实验的治疗包括两个磷酸盐剂量和7个不同的砷酸盐浓度范围从0到8毫克的As L-1定期适用于整个170=天移植后的生长期，直到植物准备收获。灌溉水中砷浓度的增加显着降低了株高、籽粒产量、实粒数、粒重和根系生物量，而根系、稻草和稻壳中的砷浓度显着增加。稻米中砷的浓度未超过食品卫生浓度限值（1.0 mg As kg（-1）干重）。稻草中砷的含量（最高砷处理达91.8mg kg（-1））与根中砷的含量（最高达107.5mg kg（-1））处于同一数量级，表明砷很容易转移到地上部。虽然不受食品卫生法规的保护，但在包括孟加拉国在内的许多国家，稻草被用作牛饲料。高砷浓度可能对牛的健康产生不利影响，并通过植物-动物-人类途径增加人类的砷暴露。施磷对水稻除谷壳外各部位的砷含量无明显影响。由于稻米中砷的浓度较低，因此仅对稻草进行砷形态分析，以预测将受污染的稻草饲喂牛的风险。砷在组织中的形态（使用HPLC-ICP-MS）显示，目前在秸秆中的主要物种是砷酸盐，其次是亚砷酸盐和二甲基胂酸（DMAA）。由于DMAA只存在于低浓度下，这不太可能大大改变大米中砷的毒性。
The 5 use of arsenic (As) contaminated groundwater for irrigation of crops has resulted in elevated concentrations of arsenic in agricultural soils in Bangladesh, West Bengal (India), and elsewhere. Paddy rice (Oryza sativa L.) is the main agricultural crop grown in the arsenic-affected areas of Bangladesh. There is, therefore, concern regarding accumulation of arsenic in rice grown those soils. A greenhouse study was conducted to examine the effects of arsenic-contaminated irrigation water on the growth of rice and uptake and speciation of arsenic. Treatments of the greenhouse experiment consisted of two phosphate doses and seven different arsenate concentrations ranging from 0 to 8 mg of As L-1 applied regularly throughout the 170=day post-transplantation growing period until plants were ready for harvesting. Increasing the concentration of arsenate in irrigation water significantly decreased plant height, grain yield, the number of filled grains, grain weight, and root biomass, while the arsenic concentrations in root, straw, and rice husk increased significantly. Concentrations of arsenic in rice grain did not exceed the food hygiene concentration limit (1.0 mg of As kg(-1) dry weight). The concentrations of arsenic in rice straw (up to 91.8 mg kg(-1) for the highest As treatment) were of the same order of magnitude as root arsenic concentrations (up to 107.5 mg kg(-1)), suggesting that arsenic can be readily translocated to the shoot. While not covered by food hygiene regulations, rice straw is used as cattle feed in many countries including Bangladesh. The high arsenic concentrations may have the potential for adverse health effects on the cattle and an increase of arsenic exposure in humans via the plant-animal-human pathway. Arsenic concentrations in rice plant parts except husk were not affected by application of phosphate. As the concentration of arsenic in the rice grain was low, arsenic speciation was performed only on rice straw to predict the risk associated with feeding contaminated straw to the cattle. Speciation of arsenic in tissues (using HPLC-ICP-MS) revealed that the predominant species present in straw was arsenate followed by arsenite and dimethylarsinic acid (DMAA). As DMAA is only present at low concentrations, it is unlikely this will greatly alter the toxicity of arsenic present in rice.