The 2-dimensional to 3-dimensional growth transition in Physcomitrella patens

进化史上的一个重要事件是植物在陆地上的殖民。轮藻属绿色藻类是陆地植物的姐妹类群，其生长发生在顶端原始细胞，只有一个或两个切面，产生简单的形态。从水到陆地的运动伴随着顶端初始细胞的获得，这些细胞可以在三个平面上分裂。3-因此，三维生长是所有陆地植物的一个决定性特征，它支撑着构成重要陆地生态系统基础的结构复杂的生物群落。开花植物的3D生长开始于胚胎发生期间。出于这个原因，开花植物如拟南芥不能轻易地被用来研究3D生长的遗传基础。然而，它是可能的遗传解剖模型苔藓小立碗藓，现存的代表最早的分歧陆地植物谱系之一的三维增长。在P.patens中，二维（2D）生长阶段先于3D生长起始，并且该2D阶段可以无限期地维持。因此，正向遗传学可用于在P.patens中产生可行的3D缺陷突变体，然后可使用基于体细胞杂交的方法来鉴定致病突变，并有助于阐明支撑植物3D生长的潜在调控网络。先前表明，NO GAMETOPHORES 1（PpNOG 1）基因对于P.patens中的3D生长是必需的。本项目的目的是进一步研究PpNOG 1在P.patens中的功能，并通过比较的方法，在A. thaliana.该项目的第一链将确定PpNOG1相互作用伙伴。其次，分析了NOG 1在A.将对泰国进行考察。此外，该项目还将研究PpNOG 1对细胞分裂平面的影响，并研究向3D生长过渡期间的植物激素信号传导。最后，转录组学将用于收集3D缺陷突变体Ppnog 1和2与野生型转录差异的全貌。

An important event in evolutionary history was the colonisation of the land by plants. In the charophyte green algae, the sister group of land plants, growth occurs from apical initial cells with only one or two cutting faces, producing simple forms. The movement from water to land was accompanied by the acquisition of apical initial cells that could cleave in three planes. 3-dimensional (3D) growth is thus a defining feature of all land plants, which underpins structurally complex biomes that form the foundation of important terrestrial ecosystems. The onset of 3D growth in flowering plants occurs during embryogenesis. For this reason, flowering plants such a Arabidopsis thaliana cannot easily be exploited to investigate the genetic basis of 3D growth. However, it is possible to genetically dissect 3D growth in the model moss Physcomitrella patens, an extant representative of one of the earliest diverging land plant lineages. In P. patens, a 2-dimensional (2D) growth phase precedes 3D growth initiation and this 2D phase can be maintained indefinitely. Consequently, forward genetics can be used to create viable 3D-defective mutants in P. patens and a somatic hybidisation based approach can then be used to identify causative mutations, and help elucidate the underlying regulatory networks underpinning 3D growth in plants. It was previously shown that the NO GAMETOPHORES 1 (PpNOG1) gene is essential for 3D growth in P. patens. The aim of this project is to perform further functional characterisation of PpNOG1 in P. patens, and through a comparative approach, in A. thaliana. The first strand of the project will determine the PpNOG1 interaction partners. Next, the function of NOG1 in A. thaliana will be explored. Additionally, the project will examine the effect of PpNOG1 on cell division planes and investigate phytohormone signalling during the transition to 3D growth. Finally, transcriptomics will be used to glean a full picture of how the 3D-defective mutants Ppnog1 & 2 differ transcriptionally from wild type.