Center for Plant Molecular Biology - Developmental Genetics, University of Tübingen, Auf der Morgenstelle 3, D-72076 Tübingen, Germany.
Eur J Cell Biol. 2010 Feb-Mar;89(2-3):138-44. doi: 10.1016/j.ejcb.2009.11.020. Epub 2009 Dec 29.
How the apical-basal axis of polarity is established in embryogenesis is still a mystery in plant development. This axis appeared specifically compromised by mutations in the Arabidopsis GNOM gene. Surprisingly, GNOM encodes an ARF guanine-nucleotide exchange factor (ARF-GEF) that regulates the formation of vesicles in membrane trafficking. In-depth functional analysis of GNOM and its closest relative, GNOM-LIKE 1 (GNL1), has provided a mechanistic explanation for the development-specific role of a seemingly mundane trafficking regulator. The current model proposes that GNOM is specifically involved in the endosomal recycling of the auxin-efflux carrier PIN1 to the basal plasma membrane in provascular cells, which in turn is required for the accumulation of the plant hormone auxin at the future root pole through polar auxin transport. Thus, the analysis of GNOM highlights the importance of cell-biological processes for a mechanistic understanding of development.
在胚胎发生中，顶端 - 基底极性轴是如何建立的仍然是植物发育中的一个谜。这个轴特别受到拟南芥 GNOM 基因突变的影响。令人惊讶的是，GNOM 编码一种 ARF 鸟嘌呤核苷酸交换因子（ARF-GEF），它调节膜运输中囊泡的形成。对 GNOM 及其最接近的同源物 GNOM-LIKE 1（GNL1）的深入功能分析，为看似平凡的运输调节剂在发育中的特定作用提供了机制解释。目前的模型提出，GNOM 专门参与生长素外排载体 PIN1 在血管前细胞中的内体再循环，这反过来又通过极性生长素运输在未来的根极处积累植物激素生长素所必需的。因此，对 GNOM 的分析强调了细胞生物学过程对于发育的机制理解的重要性。
