OsNRAMP1transporter contributes to cadmium and manganese uptake in rice
OsNRAMP1transporter contributes to cadmium and manganese uptake in rice
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OsNRAMP1转运蛋白有助于水稻镉和锰的吸收
DOI：
10.1111/pce.13843
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发表时间：
2020-08-12
影响因子：
7.3
通讯作者：
Zhao, Fang-Jie
中科院分区：
文献类型：
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作者：
Chang, Jia-Dong;Huang, Sheng;Zhao, Fang-Jie
大米是有毒金属镉(Cd)的主要饮食来源。以前的研究报道，水稻转运蛋白OsNRAMP1(天然抗性相关巨噬细胞蛋白1)可以在异源酵母中转运铁(Fe)、镉(Cd)和砷(As)。然而，OsNRAMP1的植物功能仍不清楚。在此，我们发现OsNRAMP1在酵母中表达时能够转运Cd和Mn，但不转运Fe和As。OsNRAMP1主要在根和叶片中表达，编码一种质膜定位的蛋白。免疫组织化学染色表明，OsNRAMP1定位于除中央维管系统外的所有根细胞和叶肉细胞中。OsNRAMP1基因敲除后，水稻根系对Cd、Mn的吸收和积累显著降低，对缺锰的敏感度增加。与OsNRAMP5基因敲除相比，OsNRAMP1基因敲除对Cd和Mn吸收的影响较小，而这两个基因的敲除都导致这两种金属的吸收大幅下降。总之，OsNRAMP1对水稻对Mn和Cd的吸收有显著贡献，OsNRAMP1和OsNRAMP5的功能相似但不是多余的。
Rice is a major dietary source of the toxic metal, cadmium (Cd). Previous studies reported that the rice transporter, OsNRAMP1, (Natural resistance-associated macrophage protein 1) could transport iron (Fe), Cd and arsenic (As) in heterologous yeast assays. However, thein plantafunction of OsNRAMP1 remains unknown. Here, we showed that OsNRAMP1 was able to transport Cd and manganese (Mn) when expressed in yeast, but did not transport Fe or As.OsNRAMP1was mainly expressed in roots and leaves and encoded a plasma membrane-localized protein.OsNRAMP1expression was induced by Cd treatment and Fe deficiency. Immunostaining showed that OsNRAMP1 was localized in all root cells, except the central vasculature, and in leaf mesophyll cells. The knockout ofOsNRAMP1resulted in significant decreases in root uptake of Cd and Mn and their accumulation in rice shoots and grains, and increased sensitivity to Mn deficiency. The knockout ofOsNRAMP1had smaller effects on Cd and Mn uptake than knockout ofOsNRAMP5, while knockout of both genes resulted in large decreases in the uptake of the two metals. Taken together, OsNRAMP1 contributes significantly to the uptake of Mn and Cd in rice, and the functions of OsNRAMP1 and OsNRAMP5 are similar but not redundant.