Trafficking to the Outer Polar Domain Defines the Root-Soil Interface
Trafficking to the Outer Polar Domain Defines the Root-Soil Interface
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DOI：
10.1016/j.cub.2010.03.059
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发表时间：
2010-05-25
期刊：
影响因子：
9.2
通讯作者：
Friml, Jiri
中科院分区：
文献类型：
--
作者：
Langowski, Lukasz;Ruzicka, Kamil;Friml, Jiri
在动物中，生物与环境的界面是由上皮构成的。在植物中，根与土壤之间的营养物质和信号交换对植物的生存至关重要，但细胞机制下的上皮样功能和蛋白质在根表面的特异性定位尚未确定[10]。在此，我们分析了蛋白质BOR4、ABCG37和PEN3在根土界面的极性传递机制，这三个蛋白质分别负责运输营养物质[2]、运输植物激素[3]和防御病原体[3]。在单个细胞中同时可视化这些蛋白质和顶端和基部的货物表明，最外层的细胞侧代表一个额外的极性域。外极域的递送取决于ARF GEF[4]和肌动蛋白[5-8]的功能，但不需要已知的顶端或基部靶向分子成分。与已知的基部和根尖转运不同[9,10]，外极性转运是由极性分泌介导的。我们的研究结果表明，根的最外层细胞膜在植物细胞中定义了一个额外的极性结构域，以及一个特定的、以前未被表征的极性靶向机制，这对于定义功能的、上皮样根-土壤界面非常重要。
In animals, the interface between organism and environment is constituted by the epithelium [1]. In plants, the exchange of nutrients and signals between root and soil is crucial for their survival, but the cellular mechanisms underlying the epithelium-like function and specific localization of proteins to the root surface have not been identified [2]. Here we analyze the mechanism of polar delivery to the root-soil interface of the proteins BOR4, ABCG37, and PEN3, which transport nutrients [2], transport plant hormones, and are required for pathogen defense [3], respectively. The simultaneous visualization of these proteins and the apical and basal cargos in a single cell demonstrates that the outermost cell side represents an additional polar domain. Delivery to this outer polar domain depends on ARF GEF [4] and actin [5-8] function but does not require known molecular components of the apical or basal targeting. The outer polar delivery is, in contrast to known basal and apical cargos [9, 10], mediated by the polar secretion. Our findings show that the outermost cell membranes of roots define an additional polar domain in plant cells along with a specific, previously uncharacterized, polar targeting mechanism that is important for defining the functional, epithelium-like root-soil interface.