Identifying mechanisms for stem cell division plane orientation in plants

植物形态是植物生产力和产量的主要决定因素，影响光的截获和光合作用。由于植物细胞被细胞壁捆绑在一起，不能移动，形状作为平面的结果出现在芽尖干细胞的新分裂、细胞命运决定和随后的细胞生长。拟南芥等开花植物模型具有复杂的组织结构，可以掩盖细胞分裂平面的缺陷。每个基因家族有许多基因，这可能会使识别突变变得困难。由于这些原因，干细胞分裂平面方向的遗传调节因子还很少被发现。与开花植物相比，苔藓有简单的组织结构，每个生长期只有一个干细胞，每个基因家族几乎没有基因。我的实验室已经确定，CLAVATA受体样激酶决定了苔藓干细胞分裂的平面[1，2]。尽管苔藓与开花植物有很远的亲缘关系，但我们的发现可以转移到拟南芥，我们正在建立一条知识转移的管道，通过操纵小麦的CLAVATA功能来提高产量[3]。该项目在管道的基本端进行反馈，旨在利用MOSS模型的优势来揭示CLAVATA功能的下游效应器，该功能决定了植物生长点干细胞分裂的平面。为此，该项目将：5.通过RNAseq和生物信息学分析确定CLAVATA的下游靶标6.产生候选靶标的突变并分析突变表型7.使用计算方法分析基因调控网络结构8.使用抑制子筛选确定新的细胞分裂平面调控因子。通过将计算和湿实验室方法相结合，该项目将在植物开发领域的前沿提供培训。它将受益于SWBioDTP方案中包括的更多正式教学和实习机会。学生将学到的技能和技术将广泛应用于学术生物学和生物技术领域，并可在科学政策、出版和计算机等领域广泛移植。[1]哈里森等人。2009年。局部线索和不对称的细胞分裂支撑着苔藓Physcomitrella patens的身体计划转变。当代生物学19：1-11。[2]Whitewoods等人。2018年。棍棒是陆地植物三维生长形态创新的一种遗传新奇。当代生物学28：2365-2376。[3]Fletcher 2018年。CLV-WUS干细胞信号通路：作物产量优化的路线图。植物7：87。

Plant shape is a primary determinant of plant productivity and yield, affecting light interception and photosynthesis. As plant cells are bound by a cell wall and cannot move, shape arises as an outcome of the plane new divisions in stem cells at the shoot tips, cell fate determination and subsequent cell growth. Flowering plant models such as Arabidopsis have complex tissue organizations that can mask cell division plane defects. There are many genes per gene family, which can make it hard to identify mutants. For these reasons, few genetic regulators of stem cell division plane orientation have been discovered. In contrast to flowering plants, mosses have simple tissue organizations with a single stem cell at each growing point, and there are few genes per gene family. My lab has determined that the CLAVATA receptor-like kinase sets the plane of moss stem cell divisions [1, 2]. Although mosses are distantly related to flowering plants, our findings were transferable to Arabidopsis, and we are building a pipeline for knowledge transfer to improve yield by manipulating CLAVATA function in wheat [3]. This project feeds in at the fundamental end of the pipeline, aiming to harness the advantages of the moss model to reveal downstream effectors of CLAVATA function that determine the plane of stem cell divisions at plants' growing points. To this end the project will: 5. Identify downstream targets of CLAVATA by RNAseq and bioinformatic analysis 6. Generate mutants of a candidate target and analyse mutant phenotypes 7. Analyse gene regulatory network architecture using computational approaches 8. Identify novel cell division plane regulators using a suppressor screen. By combining computational and wet lab approaches, the project will provide training at the cutting edge of the plant development field. It will benefit from further formal teaching and internships included in the SWBioDTP programme. The skills and techniques the student will learn will be broadly applicable in the academic biology and biotech sectors and widely transferable amongst areas such as science policy, publishing and computing. [1] Harrison et al. 2009. Local cues and asymmetric cell divisions underpin body plan transitions in the moss Physcomitrella patens. Current Biology 19: 1-11. [2] Whitewoods et al. 2018. CLAVATA was a genetic novelty for the morphological innovation of 3D growth in land plants. Current Biology 28: 2365-2376. [3] Fletcher 2018. The CLV-WUS stem cell signaling pathway: a roadmap to crop yield optimization. Plants 7: 87.