Coordination Funds

植物分生组织是植物结构、植物多样化和适应环境胁迫的主要决定因素。此外，分生组织对作物的生产力至关重要，因为它们直接决定产量。营养分生组织决定植物体的基本平面，并产生植物地上和地下的所有部分。在开花时间检查点的调控下，营养分生组织向生殖分生组织过渡，形成性器官和生殖细胞。在模式植物拟南芥中的研究表明，分生组织是由干细胞壁龛组成的，这些壁龛由干细胞包围的很少分裂的组织细胞组成。该物种的干细胞龛由受体激酶感知的干细胞促进因子和移动配体的负反馈回路调节。与拟南芥相比，禾本科（谷物）的茎和根结构非常复杂，包括经济上重要的作物玉米、小麦、水稻和大麦。禾本科产生较大的营养分生组织，产生额外的器官，如种子和冠根，以及高度复杂的花序分生组织，而分生组织类型在异穗状花序中是没有的。控制草分生组织功能的基因突变在作物驯化过程中起着关键作用。尽管它们具有重要的经济意义，但我们对分生组织发育和谷物干细胞系统的组织的了解非常有限。迄今为止的研究表明，基于拟南芥研究的范式并不普遍适用。FOR5235研究单元的目标是进一步了解两个主要谷物家族中决定分生组织建立、维持和终止的复杂信号和基因调节网络及其相互作用。FOR5235项目的pi们将把他们互补的专业知识、研究兴趣和资源结合起来，以玉米为例，以热带谷物作物（Panicoideae）为例，以大麦为例，以温带谷物作物（Pooideae）为例，以短柄草为例，测试一些可行的假设。他们特别致力于探索谷物的复杂分生组织是基于保守但强烈修饰的，还是基于新的信号通路和相关的基因调控网络。由于从所有主要谷物分生组织及其干细胞系统中产生基因表达和标记图谱的整体和比较方法，预计将产生重大的新见解。新的干细胞基因将被鉴定出来，与进一步的作物改良高度相关。联合开发的工具包和鉴定的新基因将在预期的第二个资助期内使用和扩展，以加深我们对谷物干细胞系统的理解，特别是了解调节系统的遗传变异和环境方面。

Plant meristems are major determinants of plant architecture, plant diversification and acclimation to environmental stresses. Moreover, meristems are fundamentally important for the productivity of crop plants as they directly determine yield. The vegetative meristems determine the basic plant body plan and produce all above- and below-ground parts of plants. Regulated by flowering time checkpoints, vegetative meristems transit to reproductive meristems forming sexual organs and germ cells. Work in the model plant Arabidopsis revealed that meristems are organized by stem cell niches consisting of rarely dividing organizing cells, which are surrounded by stem cells. Stem cell niches in this species are regulated by negative-feedback loops of stem cell promoting factors and mobile ligands that are perceived by receptor kinases.In contrast to Arabidopsis, the shoot and root architectures of grasses (cereals) including the economically important crops maize, wheat, rice and barley are very complex. Grasses generate larger vegetative meristems, produce additional organs like seminal and crown root as well as highly complex inflorescence meristems with meristem types absent in eudicots. Mutations in genes controlling grass meristem functions have played key roles during crop domestication. Despite their economic importance, our understanding of meristem development and the organization of cereal stem cell systems is very limited. Studies reported so far indicated that paradigms based on studies using Arabidopsis are not universally applicable.The goal of research unit FOR5235 is to further our understanding of the complex signaling and gene regulating networks and their interaction that determine meristem establishment, maintenance and termination in the two major cereal families. With a focus on maize as an example for a tropical cereal crop (Panicoideae), barley as an example for a temperate cereal crop (Pooideae) and its close relative model grass Brachypodium, the PIs of FOR5235 will combine their complementing expertise, research interest and resources to test a number of working hypothesis. They especially aim to explore whether the complex meristems of cereals are based on conserved but strongly modified, or also on novel signaling pathways and associated gene regulatory networks. Major novel insights are expected due to the holistic and comparative approach to generate gene expression and marker atlases from all major cereal meristems and their stem cell systems. Novel stem cell genes will be identified that are highly relevant for further crop improvement. The jointly developed toolkit and identified novel genes will be used and extended in the anticipated second funding period to deepen our understanding about cereal stem cell systems, but especially to understand also genetic variation and environmental aspects modulating the systems.