Aquaporin isoforms responsive to salt and water stresses and phytohormones in radish seedlings.
Aquaporin isoforms responsive to salt and water stresses and phytohormones in radish seedlings.
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DOI：
10.1093/pcp/pcf148
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发表时间：
2002-10
影响因子：
4.9
通讯作者：
S. Suga;S. Komatsu;M. Maeshima
中科院分区：
文献类型：
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作者：
S. Suga;S. Komatsu;M. Maeshima
植物浆膜和液泡膜上的水通道蛋白在细胞间和细胞内的水运输中起着关键作用。首先，我们定量了萝卜幼苗下胚轴中8种水通道蛋白亚型mrna的绝对数量。然后，我们研究了盐和水胁迫（150 mM NaCl、300 mM甘露醇和20%聚乙二醇）和植物激素（赤霉素酸、脱落酸和油菜素内酯）对质膜（RsPIP1-1、1-2、1-3、2-1、2-2和2-3）和液泡膜（RsTIP1-1和2-1）水通道蛋白mRNA和蛋白水平的影响。RsTIP1-1、RsTIP2-1、RsPIP1-1、RsPIP1-2和RsPIP1-3的mRNA和蛋白水平相对稳定。相反，甘露醇处理改变了根中RsPIP2-1、RsPIP2-2和RsPIP2-3的mRNA水平。免疫印迹分析显示，NaCl处理后RsPIP2-1蛋白水平升高，甘露醇和聚乙二醇处理后RsPIP2-1蛋白水平降低。赤霉素酸和脱落酸抑制了根中RsPIP2-1、RsPIP2-2和RsPIP2-3 mrna水平和RsPIP2-1蛋白水平。另一方面，rspip1组成员和RsTIPs的蛋白水平几乎没有受到这些植物激素的影响。对于下胚轴和子叶，8种亚型的mRNA和蛋白水平不受任何处理的显著影响。这些结果表明，至少在蛋白水平上，根系中的水通道蛋白，尤其是RsPIP2组可能是一种应激响应型的水通道蛋白。
Aquaporins in the plasma and vacuolar membranes play a key role in the intercellular and intracellular water transport in plants. First, we quantitated the absolute amounts for mRNAs of eight aquaporin isoforms in hypocotyls of radish seedlings. Then, we investigated the effects of salt and water stresses (150 mM NaCl, 300 mM mannitol and 20% polyethylene glycol) and phytohormones (gibberellic acid, abscisic acid and brassinolide) on the mRNA and protein levels of aquaporins in the plasma membrane (RsPIP1-1, 1-2, 1-3, 2-1, 2-2 and 2-3) and vacuolar membrane (RsTIP1-1 and 2-1). The mRNA and protein levels of RsTIP1-1, RsTIP2-1, RsPIP1-1, RsPIP1-2 and RsPIP1-3 were comparatively constant. In contrast, mannitol treatment altered the mRNA levels of RsPIP2-1, RsPIP2-2 and RsPIP2-3 in roots. Immunoblot analysis showed that the RsPIP2-1 protein level was increased by NaCl treatment and decreased by treatment with mannitol and polyethylene glycol. Gibberellic acid and abscisic acid suppressed the levels of mRNAs of RsPIP2-1, RsPIP2-2 and RsPIP2-3 and the protein level of RsPIP2-1 in roots. On the other hand, the protein levels of RsPIP1-group members and RsTIPs were scarcely changed by these phytohormones. In the case of hypocotyls and cotyledons, the mRNA and protein levels of eight isoforms were not markedly affected by any treatment. These results indicate that aquaporins in the root, especially the RsPIP2 group, may be a stress responsive type of aquaporin at least in the protein level.