Functional analysis of the WUSCHEL HOMEOBOX (WOX) gene family in Arabidopsis

拟南芥同源框基因家族由15个基因组成，编码具有独特的植物特有同源结构域的蛋白质和一个未知功能的额外基序。我们已经分离了14个WOX开放阅读框架的cDNA，并表明大多数WOX基因在一小群未成熟细胞中瞬时表达，这表明在细胞类型特定的发育中发挥重要作用。然而，正向遗传筛查发现了两个在细胞命运决定中具有关键功能的Wox基因的突变，但没有发现任何其他Wox基因的突变。与此一致，我们的初步遗传学研究表明，该转录因子家族成员之间存在功能冗余。因此，为了了解WOX基因家族的功能，需要采用系统的反向遗传学方法。为此，我们将首先使用功能丧失和功能获得两种方法来研究worx基因的功能过程。其次，我们将通过研究WOX活动与已知植物发育调节因子的遗传相互作用，以及通过分析蛋白质-蛋白质相互作用，寻求将WOX活动整合到调控网络中。在我们的准备工作中，我们已经建立了许多工具(突变体、转基因系、互作子)来及时阐明worx基因的功能，并承诺通过转录调控来增加我们对植物细胞类型发育的了解。

The Arabidopsis WOX homeobox gene family comprises 15 genes encoding proteins with a unique and plant specific homeodomain and an additional motif of yet unknown function. We have isolated cDNAs for 14 WOX open reading frames and showed that most WOX genes are expressed transiently in small groups of immature cells, suggesting important roles in cell type specific development. However, forward genetic screens identified mutants for two WOX genes with crucial functions in cell fate specification, but did not uncover mutations in any other WOX gene. Consistent with this, our preliminary genetic studies show functional redundancy between members of this transcription factor family. Thus, to understand the functions of the WOX gene family a systematic reverse genetic approach needs to be employed. For this purpose, we will first examine the processes in which WOX genes function using both loss and gain-of-function approaches. Second, we will seek to integrate WOX activities into regulatory networks by studying their genetic interactions with known regulators of plant development and by analyzing protein-protein interactions. In our preparatory work, we have already established many tools (mutants, transgenic lines, interactors) to allow for a timely elucidation of WOX gene function, promising to increase our knowledge of plant cell type development by transcriptional regulation.