In shoots, polar auxin transport is basipetal (that is, from the shoot apex toward the base) and is driven by the basal localization of the auxin efflux carrier complex. The focus of this article is to summarize the experiments that have examined how the asymmetric distribution of this protein complex is controlled and the significance of this polar distribution. Experimental evidence suggests that asymmetries in the auxin efflux carrier may be established through localized secretion of Golgi vesicles, whereas an attachment of a subunit of the efflux carrier to the actin cytoskeleton may maintain this localization. In addition, the idea that this localization of the efflux carrier may control both the polarity of auxin movement and more globally regulate developmental polarity is explored. Finally, evidence indicating that the gravity vector controls auxin transport polarity is summarized and possible mechanisms for the environmentally induced changes in auxin transport polarity are discussed.

中文翻译：

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通过与肌动蛋白细胞骨架的相互作用维持生长素转运蛋白的不对称细胞定位

在枝条中，生长素极性转运是基叶的（即从枝条顶端到基部），并由生长素外排载体复合物的基底定位驱动。本文的重点是总结研究如何控制这种蛋白质复合物的不对称分布以及这种极性分布的重要性的实验。实验证据表明，生长素外排载体的不对称性可能是通过高尔基体囊泡的局部分泌建立的，而外排载体亚基与肌动蛋白细胞骨架的连接可能会维持这种定位。此外，探索了外排载体的这种定位可能控制生长素运动的极性和更全面地调节发育极性的想法。最后，