Knocking Out OsPT4 Gene Decreases Arsenate Uptake by Rice Plants and Inorganic Arsenic Accumulation in Rice Grains
Knocking Out OsPT4 Gene Decreases Arsenate Uptake by Rice Plants and Inorganic Arsenic Accumulation in Rice Grains
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敲除 OsPT4 基因可减少水稻植株对砷的吸收以及米粒中无机砷的积累
DOI：
10.1021/acs.est.7b03028
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发表时间：
2017-11-07
影响因子：
11.4
通讯作者：
Ma, Lena Q.
中科院分区：
文献类型：
--
作者：
Cao, Yue;Sun, Dan;Ma, Lena Q.
稻米中砷(As)的积累对人类健康构成威胁。包括水稻在内的植物通过磷酸盐转运体吸收砷(ASV)。本研究基于水稻磷酸盐转运蛋白OsPT4的两个独立的T-DNA插入突变体(M1和M2)，对水稻磷酸盐转运蛋白OsPht4(OsPht1；4)进行了研究，它们表现出比野生型WT1和WT1更强的ASV抗性。WT2.当在含有ASV的培养基(+P或-P)中培养时，Ospt4突变体的积累比在植物中低16-32%，这表明OsPT4介导了ASV的吸收。对木质部汁液的分析表明，在-P条件下，OSPT4突变体的ASV浓度比WT对照低20-40%，这表明OSPT4也可能参与ASV的转运。此外，动力学分析表明，Ospt4突变体的ASV摄取速率低于WT对照，进一步证明OsPT4在水稻中具有ASV转运蛋白的功能。当水稻生长在砷淹水土壤中时，SPT4突变体水稻籽粒中的ASV浓度下降了50-55%。更重要的是，在M2中敲除OsPT4可使水稻籽粒中无机砷的积累量减少20-44%，这对控制水稻砷暴露风险具有重要意义。综上所述，我们的研究结果揭示了OsPT4在水稻对ASV的吸收和转运中的关键作用。基因敲除OsPT4有效地减少了水稻籽粒中无机砷的积累，为转基因低砷水稻提高食品安全提供了线索。
Arsenic (As) accumulation in rice grains poses health risk to humans. Plants including rice take up arsenate (AsV) by phosphate transporters. In this study, rice phosphate transporter OsPT4 (OsPht1;4) was investigated based on two independent T-DNA insertion mutants of OsPT4 (M1 and M2), which displayed stronger AsV resistance than wild types WT1 and. WT2. When cultivated in medium (+P or -P) with AsV, ospt4 mutants accumulated 16-32% lower As in plants, suggesting that OsPT4 mediates AsV uptake. Analysis of the xylem sap showed that AsV concentrations in ospt4 mutants was 20-40% lower than WT controls under -P condition, indicating OSPT4 may also mediate AsV translocation. Moreover, kinetics analysis showed that ospt4 mutants had lower AsV uptake rates than the WT controls, further proving that OsPT4 functions as an AsV transporter in rice. When grown in flooded soils with As, AsV concentrations in rice grains of ospt4 mutants decreased by 50-55%. More importantly, knocking out OsPT4 in M2 reduced inorganic As accumulation in rice grains by 20-44%, significant for controlling As exposure risk from rice. Taken together, our findings revealed a critical role of OsPT4 in AsV uptake and translocation in rice. Knocking out OsPT4 effectively decreased inorganic As accumulation in rice grains, shedding light on engineering low-As rice to enhance food safety.