Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB), Gent, Belgium.
PLoS Genet. 2013 May;9(5):e1003540. doi: 10.1371/journal.pgen.1003540. Epub 2013 May 30.
PIN-FORMED (PIN) proteins localize asymmetrically at the plasma membrane and mediate intercellular polar transport of the plant hormone auxin that is crucial for a multitude of developmental processes in plants. PIN localization is under extensive control by environmental or developmental cues, but mechanisms regulating PIN localization are not fully understood. Here we show that early endosomal components ARF GEF BEN1 and newly identified Sec1/Munc18 family protein BEN2 are involved in distinct steps of early endosomal trafficking. BEN1 and BEN2 are collectively required for polar PIN localization, for their dynamic repolarization, and consequently for auxin activity gradient formation and auxin-related developmental processes including embryonic patterning, organogenesis, and vasculature venation patterning. These results show that early endosomal trafficking is crucial for cell polarity and auxin-dependent regulation of plant architecture.
PIN 蛋白定位于质膜的不对称位置，并介导植物激素生长素的细胞间极性运输，这对植物的多种发育过程至关重要。PIN 的定位受到环境或发育线索的广泛控制，但调节 PIN 定位的机制尚不完全清楚。在这里，我们表明早期内体成分 ARF GEF BEN1 和新鉴定的 Sec1/Munc18 家族蛋白 BEN2 参与了早期内体运输的不同步骤。BEN1 和 BEN2 共同参与极性 PIN 定位、动态重极化，以及生长素活性梯度形成和生长素相关发育过程，包括胚胎模式形成、器官发生和脉管系统脉纹模式形成。这些结果表明，早期内体运输对于细胞极性和生长素依赖性调节植物结构至关重要。
