HvLsi1 is a silicon influx transporter in barley
HvLsi1 is a silicon influx transporter in barley
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DOI：
10.1111/j.1365-313x.2008.03728.x
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发表时间：
2009-03-01
期刊：
影响因子：
7.2
通讯作者：
Ma, Jian Feng
中科院分区：
文献类型：
--
作者：
Chiba, Yukako;Mitani, Namiki;Ma, Jian Feng
大多数植物积累硅在他们的身体，这被认为是重要的生物和非生物胁迫的抗性，然而，硅吸收和积累的分子机制知之甚少。在这里，我们描述了一个硅流入转运，HvLsi 1，在大麦。该蛋白与水稻内流转运蛋白OsLsi 1同源性为81%，属于Nod 26-like水通道蛋白的主要内在蛋白亚家族。HvLsi 1在非洲爪蟾卵母细胞和水稻突变体中的表达表明，HvLsi 1具有转运油酸的活性。HvLsi 1基因在根中特异表达，其表达水平不受Si供应的影响。供试8个品种的硅吸收量与HvLsi 1的表达量呈弱相关。在种子根中，HvLsi 1定位于表皮和皮层细胞远端侧的质膜上。HvLsi 1也位于下皮细胞质膜上的侧根中。HvLsi 1的这些定位和表达模式的细胞类型特异性不同于OsLsi 1。这些观察结果表明，HvLsi 1是一个硅流入转运，参与径向运输硅通过表皮和皮层的大麦的基底根。
Most plants accumulate silicon in their bodies, and this is thought to be important for resistance against biotic and abiotic stresses; however, the molecular mechanisms for Si uptake and accumulation are poorly understood. Here, we describe an Si influx transporter, HvLsi1, in barley. This protein is homologous to rice influx transporter OsLsi1 with 81% identity, and belongs to a Nod26-like major intrinsic protein sub-family of aquaporins. Heterologous expression in both Xenopus laevis oocytes and a rice mutant defective in Si uptake showed that HvLsi1 has transport activity for silicic acid. Expression of HvLsi1 was detected specifically in the basal root, and the expression level was not affected by Si supply. There was a weak correlation between Si uptake and the expression level of HvLsi1 in eight cultivars tested. In the seminal roots, HvLsi1 is localized on the plasma membrane on the distal side of epidermal and cortical cells. HvLsi1 is also located in lateral roots on the plasma membrane of hypodermal cells. These cell-type specificity of localization and expression patterns of HvLsi1 are different from those of OsLsi1. These observations indicate that HvLsi1 is a silicon influx transporter that is involved in radial transport of Si through the epidermal and cortical layers of the basal roots of barley.