Acceleration of Vacuolar Regeneration and Cell Growth by Overexpression of an Aquaporin NtTIP1;1in Tobacco BY-2 Cells
Acceleration of Vacuolar Regeneration and Cell Growth by Overexpression of an Aquaporin NtTIP1;1in Tobacco BY-2 Cells
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DOI：
10.1093/pcp/pcn181
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发表时间：
2009-01-01
影响因子：
4.9
通讯作者：
Hasezawa, Seiichiro
中科院分区：
文献类型：
--
作者：
Okubo-Kurihara, Emiko;Sano, Toshio;Hasezawa, Seiichiro
水通道蛋白是一种水通道，可通过膜结构增加水的渗透性。在植物中，液泡是细胞生长过程中经历动态体积变化的重要细胞器。为了了解水通道蛋白在植物细胞生长中的作用，我们建立了一个高表达液泡膜固有蛋白(TIP)的转基因烟草BY-2细胞系。与野生型细胞相比，TIP过表达细胞分离的液泡膜具有更高的水渗透活性。然后，我们研究了TIP在真空烟草BY-2原生质体(微型原生质体)液泡再生中的作用。在该细胞系的小原生质体中，液泡从细到粗的管状网状液泡的再生和随后的大液泡的发育被加速。细胞扩张率的平行增加表明空泡发育和细胞体积增加之间存在密切关系。有趣的是，烟草尖端的过度表达也促进了细胞分裂。因此，液泡水通道蛋白活性的增加可能通过增加液泡膜的透水性来加速细胞扩张和细胞分裂。
Aquaporin is a water channel that increases water permeability through membranous structures. In plants, vacuoles are essential organelles that undergo dynamic volume changes during cell growth. To understand the contribution of aquaporins to plant cell growth, we developed a transgenic tobacco BY-2 cell line overexpressing the tonoplast intrinsic protein (TIP), TIP. Vacuolar membranes of isolated vacuoles from TIP-overexpressing cells showed higher water permeation activities than those from wild-type cells. We then examined the role of TIP in vacuolar regeneration of evacuolated tobacco BY-2 protoplasts (miniprotoplasts). Vacuolar regeneration from thin to thick tube-network vacuoles and subsequent development of large vacuoles was accelerated in miniprotoplasts of this cell line. A parallel increase in the rate of cell expansion indicated a tight relationship between vacuolar development and cellular volume increases. Interestingly, overexpression of tobacco TIP also enhanced cell division. Thus, increased vacuolar aquaporin activity may accelerate both cell expansion and cell division by increasing water permeability through the vacuolar membrane.