OsZIP4, a novel zinc-regulated zinc transporter in rice
OsZIP4, a novel zinc-regulated zinc transporter in rice
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DOI：
10.1093/jxb/eri317
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发表时间：
2005-12-01
影响因子：
6.9
通讯作者：
Nishizawa, NK
中科院分区：
文献类型：
--
作者：
Ishimaru, Y;Suzuki, M;Nishizawa, NK
锌（Zn）是植物正常生长所必需的元素，但有关Zn在水稻（Oryza sativa L.）植物OsZIP 4、OsZIP 5、OsZIP 6和OsZIP 7基因与水稻亚铁离子转运蛋白OsIRT 1基因序列相似。基因芯片和北方印迹分析表明，OsZIP 4在缺锌条件下在根和地上部中均得到高表达。Real-time-PCR结果表明，OsZIP 4基因在缺锌的根和地上部中的表达量明显高于OsZIP 1和OsZIP 3基因。OsZIP 4与锌摄取缺陷型酵母（Saccharomycescerevisiae）突变体Δ zrt 1、Δ zrt 2互补，表明OsZIP 4是锌的功能性转运蛋白。OsZIP 4-合成的绿色荧光蛋白（sGFP）融合蛋白在洋葱表皮细胞中瞬时表达，定位于质膜。原位杂交分析表明，OsZIP 4在缺锌水稻的地上部和根中均有表达，尤其是在韧皮部细胞中。此外，OsZIP 4的转录本检测到分生组织中的锌缺乏的根和芽。这些结果表明OsZIP 4是一种锌转运蛋白，可能参与水稻体内锌的转运。
Zinc (Zn) is an essential element for the normal growth of plants but information is scarce on the mechanisms whereby Zn is transported in rice (Oryza sativa L.) plants. Four distinct genes, OsZIP4, OsZIP5, OsZIP6, and OsZIP7 that exhibit sequence similarity to the rice ferrous ion transporter, OsIRT1, were isolated. Microarray and northern blot analysis revealed that OsZIP4 was highly expressed under conditions of Zn deficiency in roots and shoots. Real-time-PCR revealed that the OsZIP4 transcripts were more abundant than those of OsZIP1 or OsZIP3 in Zn-deficient roots and shoots. OsZIP4 complemented a Zn-uptake-deficient yeast (Saccharomyces cerevisiae) mutant, Delta zrt1,Delta zrt2, indicating that OsZIP4 is a functional transporter of Zn. OsZIP4-synthetic green fluorescent protein (sGFP) fusion protein was transiently expressed in onion epidermal cells localized to the plasma membrane. In situ hybridization analysis revealed that OsZIP4 in Zn-deficient rice was expressed in shoots and roots, especially in phloem cells. Furthermore, OsZIP4 transcripts were detected in the meristem of Zn-deficient roots and shoots. These results suggested that OsZIP4 is a Zn transporter that may be responsible for the translocation of Zn within rice plants.