School of Civil Engineering and Surveying, Faculty of Health, Engineering and Sciences, University of Southern Queensland, West Street, Toowoomba, Queensland 4350, Australia.
Center for Crop Health, Faculty of Health, Engineering and Sciences, University of Southern Queensland, West Street, Toowoomba, Queensland 4350, Australia.
Sci Total Environ. 2018 Nov 15;642:485-496. doi: 10.1016/j.scitotenv.2018.06.030. Epub 2018 Jun 14.
Arsenic (As) elevation in paddy soils will have a negative impact on both the yield and grain quality of rice (Oryza sativa L.). The mechanistic understanding of As uptake, translocation, and grain filling is an important aspect to produce rice grains with low As concentrations through agronomical, physico-chemical, and breeding approaches. A range of factors (i.e. physico-chemical, biological, and environmental) govern the speciation and mobility of As in paddy soil-water systems. Major As uptake transporters in rice roots, such as phosphate and aquaglyceroporins, assimilate both inorganic (As(III) and As(V)) and organic As (DMA(V) and MMA(V)) species from the rice rhizosphere. A number of metabolic pathways (i.e. As (V) reduction, As(III) efflux, and As(III)-thiol complexation and subsequent sequestration) are likely to play a key role in determining the translocation and substantial accumulation of As species in rice tissues. The order of translocation efficiency (caryopsis-to-root) for different As species in rice plants is comprehensively evaluated as follows: DMA(V) > MMA(V) > inorganic As species. The loading patterns of both inorganic and organic As species into the rice grains are largely dependent on the genetic makeup and maturity stage of the rice plants together with environmental interactions. The knowledge of As metabolism in rice plants and how it is affected by plant genetics and environmental factors would pave the way to develop adaptive strategies to minimize the accumulation of As in rice grains.
砷（As）在稻田土壤中的升高会对水稻（Oryza sativa L.）的产量和籽粒品质产生负面影响。通过农业、物理化学和育种方法生产低砷浓度的水稻籽粒，了解砷的吸收、转运和灌浆机制是一个重要方面。一系列因素（即物理化学、生物和环境）控制着水稻根际土壤-水中砷的形态和迁移性。水稻根中的主要砷吸收转运蛋白，如磷酸盐和水通道蛋白，从水稻根际中吸收无机（As(III) 和 As(V)）和有机砷（DMA(V) 和 MMA(V)）。许多代谢途径（如 As(V)还原、As(III)外排、As(III)-巯基复合物形成和随后的隔离）可能在决定砷在水稻组织中的转运和大量积累方面发挥关键作用。不同砷形态在水稻植株中的转运效率（颖果到根）顺序如下：DMA(V) > MMA(V) > 无机砷形态。无机和有机砷形态在水稻籽粒中的加载模式在很大程度上取决于水稻植株的遗传组成和成熟阶段以及环境相互作用。了解水稻植株中的砷代谢以及它如何受到植物遗传和环境因素的影响，将为开发适应性策略以最小化砷在水稻籽粒中的积累铺平道路。
