Understanding the ancestral function of RCO/LMI1 type homeobox genes in early-divergent land plants.

我们最近发现，晚期分生组织识别1(LMI1)/降低复杂性(RCO)类型的同源结构域转录因子参与了一种新的生长调控途径，该途径是种子植物叶形进化多样化的基础。与Sabine Zachgo教授一起，我们还获得了LMI1类基因调控地钱生长的初步证据。这些发现导致了一种假设，即该途径的至少某些方面可能在苔类植物中发挥作用，因此可能代表着对早期陆地植物进化非常重要的高度保守的功能。为了验证这一假设，我们建议使用遗传学、高级成像和计算模型来表征LMI1类型基因在多态地衣模型中的功能。我们还建议研究该转录因子在模式苔藓Physchomitrella patens中的功能，这将有助于查明LMI1类基因在生长调控方面的部分功能在早期陆地植物中是否保守。最后，通过利用绿藻相关序列进行有针对性的转基因实验，我们将致力于调查生长调控所需蛋白质的结构特征是否在植物定居陆地之前就已经存在，因此可能使这种定居成为可能。

We have recently shown that homeodomain transcription factors of the Late Meristem Identity 1 (LMI1) / Reduced Complexity (RCO) type participate in a novel growth regulating pathway that underlies evolutionary diversification of leaf form in seed plants. Together with Prof. Sabine Zachgo, we have also obtained preliminary evidence that an LMI1 type gene regulates growth in the liverwort Marchantia polymorpha. These findings lead to the hypothesis that at least some aspects of this pathway may operate in liverworts and therefore may represent deeply conserved functions that were important for early land plant evolution. To test this hypothesis, we propose to characterize the function of LMI1 type genes in the model Marchantia polymorpha using genetics, advanced imaging and computational modelling. We also propose to investigate functions of this transcription factor in the model moss Physchomitrella patens which will help pinpoint if aspects of LMI1 type gene function in growth regulation were conserved in early land plants. Finally, through targeted transgenic experiments with related sequences from green algae, we will aim to investigate whether structural features of the protein necessary for growth regulation were already present before plants colonized land and therefore may have enabled this colonization.