Soto Gabriela, Alleva Karina, Mazzella María Agustina, Amodeo Gabriela, Muschietti Jorge P
Instituto de Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Vuelta de Obligado 2490 Piso 2, C1428ADN Buenos Aires, Argentina.
FEBS Lett. 2008 Dec 10;582(29):4077-82. doi: 10.1016/j.febslet.2008.11.002. Epub 2008 Nov 18.
Pollination includes processes where water and/or solute movements must be finely regulated, suggesting participation of aquaporins. Using information available from different transcriptional profilings of Arabidopsis thaliana mature pollen, we showed that the only aquaporins that are selectively and highly expressed in mature pollen are two TIPs: AtTIP1;3 and AtTIP5;1. Pollen exhibited a lower number and more exclusive type of aquaporin expressed genes when compared to other single cell transcriptional profilings. When characterized using Xenopus oocyte swelling assays, AtTIP1;3 and AtTIP5;1 showed intermediate water permeabilities. Although they displayed neither glycerol nor boric acid permeability they both transported urea. In conclusion, these results suggest a function for AtTIP1;3 and AtTIP5;1 as specific water and urea channels in Arabidopsis pollen.
授粉过程包括水和/或溶质运动必须得到精细调节的过程，这表明水通道蛋白参与其中。利用从拟南芥成熟花粉的不同转录谱中获得的信息，我们发现，在成熟花粉中选择性高表达的唯一水通道蛋白是两种液泡膜内在蛋白（TIPs）：AtTIP1;3和AtTIP5;1。与其他单细胞转录谱相比，花粉中表达的水通道蛋白基因数量较少且类型更为独特。当使用非洲爪蟾卵母细胞膨胀试验进行表征时，AtTIP1;3和AtTIP5;1表现出中等的水渗透性。尽管它们既不显示甘油渗透性也不显示硼酸渗透性，但二者都能转运尿素。总之，这些结果表明AtTIP1;3和AtTIP5;1在拟南芥花粉中作为特定的水和尿素通道发挥作用。
