Water management affects arsenic uptake and translocation by regulating arsenic bioavailability, transporter expression and thiol metabolism in rice (Oryza sativa L.)
Water management affects arsenic uptake and translocation by regulating arsenic bioavailability, transporter expression and thiol metabolism in rice (Oryza sativa L.)
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水管理通过调节水稻中砷的生物利用度、转运蛋白表达和硫醇代谢来影响砷的吸收和转运（Oryza sativa L.）
DOI：
10.1016/j.ecoenv.2020.111208
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发表时间：
2020
影响因子：
6.8
通讯作者：
Guan MY
中科院分区：
文献类型：
--
作者：
Cao ZZ;Pan JY;Yang YJ;Cao ZY;Xu P;Chen MX;Guan MY
水分管理是降低水稻籽粒中砷（As）积累的一种经济有效的策略，但水分管理对As在土壤-水稻系统中迁移转化的影响却知之甚少。采用盆栽试验，系统研究了连续淹水（CF）和间歇淹水（IF）处理对根际土壤-孔隙水-铁斑-水稻系统中As动态变化的影响。进一步研究了不同水分管理条件下水稻砷吸收转运相关基因的表达。结果表明，与IF处理相比，CF处理糙米中总砷含量增加了50.8%，其中二甲基胂酸（DMA）对CF处理糙米中总砷含量增加的贡献较大（15.5%~ 29.2%）。与IF处理相比，CF处理提高了根际土壤和土壤孔隙水中As的生物有效性，通过诱导硅转运蛋白基因OsLsi 1和OsLsi 2的表达，促进了水稻对As的吸收和向木质部的转运。此外，与IF处理相比，CF处理通过减少土壤有效硫和植物螯合素（PC）的生物合成以及水稻根中液泡的固定，增加了As从根向地上部的转移。本研究揭示了不同水分条件下水稻吸收和转运As的生理和分子机制，为采用灌溉技术减轻As在水稻籽粒中的过量积累及其对人类健康的危害提供了理论依据。
Water management is an economic and effective strategy to reduce arsenic (As) accumulation in rice grains, but little is known about the effect of water management on the migration and transformation of As in the soil-rice system. In this study, the effect of the continually (CF) and intermittent flooding (IF) treatments on the dynamic change of As in the rhizosphere soil-pore water-iron plaque-rice system was systematically investigated using pot experiments. The expressions of genes involved in As uptake and translocation in rice plants under different water management treatments were further examined. Results showed that the total As concentration in brown rice was increased by 50.8% in the CF treatment compared to the IF treatment, and dimethylarsinic acid (DMA) made greater contribution (from 15.5% to 29.2%) to total As increase in brown rice under the CF treatment. The CF treatment increased As bioavailability in the rhizosphere soil and soil pore water, which enhanced As uptake and transport to the xylem in rice plants by inducing the expressions of silicon transporter genes (OsLsi1andOsLsi2) compared to the IF treatment. Moreover, the CF treatment increased As translocation from roots to shoots by reducing soil available sulfur and phytochelatins (PCs) biosynthesis and vacuolar sequestration in rice roots compared with the IF treatment. The study provides insight into the physiological and molecular mechanisms underlying As uptake and translocation in rice plants under different water regimes, which will be helpful for adopting the irrigation technique to mitigate excessive As accumulation in rice grains and associated health risk to humans.