Overexpression of the OsZIP4 zinc transporter confers disarrangement of zinc distribution in rice plants
Overexpression of the OsZIP4 zinc transporter confers disarrangement of zinc distribution in rice plants
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DOI：
10.1093/jxb/erm147
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发表时间：
2007-09-01
影响因子：
6.9
通讯作者：
Nishizawa, Naoko K.
中科院分区：
文献类型：
--
作者：
Ishimaru, Yasuhiro;Masuda, Hiroshi;Nishizawa, Naoko K.
锌（Zn）是细胞中的必需营养素，在控制细胞过程如生长、发育和分化中起着至关重要的作用。虽然水稻（Oryza sativa）中锌转运的机制还不完全清楚，但最近引起了越来越多的兴趣。OsZIP 4是一种定位于顶端细胞的锌转运蛋白。产生在花椰菜花叶病毒（CaMV）35 S启动子控制下过表达OsZIP 4基因的转基因水稻植物。35 S-OsZIP 4转基因植物根中的Zn浓度比载体对照高10倍，但其在地上部中低5倍。与载体对照相比，35 S-OsZIP 4植物种子中的Zn浓度低四倍。北方印迹分析和实时荧光定量逆转录-PCR显示，在35 S-OsZIP 4植物的根和芽中，由CaMV 35 S启动子驱动的OsZIP 4表达的转录本，但与载体对照相比，内源OsZIP 4转录本的水平在根中低而在芽中高。基因芯片分析表明，在35 S-OsZIP 4植株地上部中表达的基因与在缺锌植株地上部中诱导表达的基因一致。这些结果表明，OsZIP 4的组成型表达改变了水稻植株内的锌分布，OsZIP 4是一个必须严格调控的关键锌转运蛋白。
Zinc (Zn), an essential nutrient in cells, plays a vital role in controlling cellular processes such as growth, development, and differentiation. Although the mechanisms of Zn translocation in rice plants (Oryza sativa) are not fully understood, it has recently received increased interest. OsZIP4 is a Zn transporter that localizes to apical cells. Transgenic rice plants overexpressing the OsZIP4 gene under the control of the cauliflower mosaic virus (CaMV) 35S promoter were produced. The Zn concentration in roots of 35S-OsZIP4 transgenic plants was 10 times higher than in those of vector controls, but it was five times lower in shoots. The Zn concentration in seeds of 35S-OsZIP4 plants was four times lower compared with vector controls. Northern blot analysis and quantitative real-time reverse transcription-PCR revealed transcripts of OsZIP4 expression driven by the CaMV 35S promoter in roots and shoots of 35S-OsZIP4 plants, but levels of endogenous OsZIP4 transcripts were low in roots and high in shoots compared with vector controls. Microarray analysis revealed that the genes expressed in shoots of 35S-OsZIP4 plants coincided with those induced in shoots of Zn-deficient plants. These results indicate that constitutive expression of OsZIP4 changes the Zn distribution within rice plants, and that OsZIP4 is a critical Zn transporter that must be strictly regulated.