Arsenic dynamics in the rhizosphere and its sequestration on rice roots as affected by root oxidation
Arsenic dynamics in the rhizosphere and its sequestration on rice roots as affected by root oxidation
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根际砷动态及其受根氧化影响的水稻根部固存
DOI：
10.1016/s1001-0742(13)60483-0
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发表时间：
2014-04-01
影响因子：
6.9
通讯作者：
Hartley, William
中科院分区：
文献类型：
--
作者：
Pan, Weisong;Wu, Chuan;Hartley, William
通过盆栽实验研究了根部氧化对根际砷（As）动态和水稻根部砷固存的影响。根际和非根际土壤pH值差异显着（P < 0.05），根际土壤pH值为5.68-6.16，非根际土壤pH值为6.30-6.37，氧化还原电位也存在显着差异（P < 0.05）。与径向氧损失 (ROL) 较低的基因型相比，径向氧损失 (ROL) 较高的水稻基因型的根际土壤溶液中亚砷酸盐百分比较低 (4%-16%) (P < 0.05)。铁斑和稻草中砷含量呈显着负相关（R = -0.60，P < 0.05）。与ROL较低的基因型（IAPAR9，1.68 mg/kg；南洋占2.24 mg/kg）相比，在As处理中，ROL较高的基因型（TD71和银晶软占）的稻米总As含量（分别为1.35和0.96 mg/kg）显着（P < 0.001），并且无机As也较低（P < 0.05）。目前的研究表明，ROL 较高的基因型可以氧化根际土壤中更多的亚砷酸盐，并诱导更多的铁斑块形成，从而螯合更多的砷。这减少了地上植物组织对砷的吸收，也减少了稻谷中无机砷的积累。该研究有助于进一步了解 ROL 影响水稻砷吸收和积累的机制。
A pot experiment was conducted to investigate the effects of root oxidation on arsenic (As) dynamics in the rhizosphere and As sequestration on rice roots. There were significant differences (P < 0.05) in pH values between rhizosphere and non-rhizosphere soils, with pH 5.68-6.16 in the rhizosphere and 6.30-6.37 in non-rhizosphere soils as well as differences in redox potentials (P < 0.05). Percentage arsenite was lower (4%-16%) in rhizosphere soil solutions from rice genotypes with higher radial oxygen loss (ROL) compared with genotypes with lower ROL (P < 0.05). Arsenic concentrations in iron plaque and rice straw were significantly negatively correlated (R = -0.60, P < 0.05). Genotypes with higher ROL (TD71 and Yinjingruanzhan) had significantly (P < 0.001) lower total As in rice grains (1.35 and 0.96 mg/kg, respectively) compared with genotypes with lower ROL (IAPAR9, 1.68 mg/kg; Nanyangzhan 2.24 mg/kg) in the As treatment, as well as lower inorganic As (P < 0.05). The present study showed that genotypes with higher ROL could oxidize more arsenite in rhizosphere soils, and induce more Fe plaque formation, which subsequently sequestered more As. This reduced As uptake in aboveground plant tissues and also reduced inorganic As accumulation in rice grains. The study has contributed to further understanding the mechanisms whereby ROL influences As uptake and accumulation in rice.