Genetic and hormonal feedbacks defining tissue polarity by broad brushes and fine PINs

遗传和激素反馈通过粗刷和精细 PIN 定义组织极性

• 批准号: BB/K008617/1
• 负责人: Lars Ostergaard
• 金额: $ 60.32万
• 依托单位: John Innes Centre
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FK008617%2F1
• 关键词: Genetic; hormonal; feedbacks; defining; tissue

Multicellular organisms such as animals and plants develop specialised organs, which are composed of different types of tissues. The structure - or pattern - of organs is determined by the polarity within tissues such as for example radial or medio-lateral symmetry. Polarity is established when cells are provided with a sense of direction. Although developmental biologists have successfully identified genes required to specify individual cell types of an organ, and even how they interact in genetic networks, we know very little about the mechanisms that regulate tissue polarity. Flowering plants evolved about 140 million years ago and today comprise more than 90% of plants of the plant kingdom. The main reason for their enormous success is the development of fruits as the reproductive organ containing the developing seeds. After fertilisation, the fruit nurtures, protects and mediates the efficient dispersal of seeds to ensure success of future generations. Fruits occur in a range of shapes and sizes, but common to all fruits is that they develop from structures called carpels in the centre of the flower that fuse to form a gynoecium. Interestingly, the German poet and scientist Johann Wolfgang von Goethe hypothesised more than 200 years ago that all floral organs are in fact modified leaves. Modern genetics and molecular biology has confirmed Goethe's prediction, and revealed that also carpels are evolutionarily derived from leaves. The gynoecium is therefore formed from a simpler basic plan and modified over time to optimise its function as a reproductive organ. These modifications have for example allowed development of ovules in the ovary at the centre of the gynoecium that will be fertilised to develop seeds. They were also responsible for producing a structure at the tip of the gynoecium called stigma to facilitate pollination, and modifications furthermore resulted in the formation of a style just below the stigma to support the development of pollen tubes, which will guide the pollen to the ovules for efficient fertilisation. Whereas the ovary has medio-lateral symmetry reflecting the origin as two fused leaves, the style and stigma adopts radial symmetry. The modifications involved in creating the gynoecium from two leaves, therefore involved changing the polarity of tissues. Mobile signals such as hormones are likely to coordinate growth of the different domains and structures in the gynoecium. Our recent work suggests that the plant hormone auxin has such a prominent role. In this proposal we will build on these preliminary data and take advantage of newly developed genetic and molecular resources, mathematical modelling as well DNA-deep-sequencing technology to:1) understand how interaction between a known set of transcription factors and auxin activity regulate polarity of specific tissues.2) identify pathways and key components regulated by the auxin/transcription factor module.3) study how the auxin distribution pattern is established. Through these studies we aim to provide a unified understanding of tissue polarity establishment during gynoecium development and to reveal the key importance of auxin in allowing the transition from vegetative leaves to a complex reproductive organ.

多细胞生物，如动物和植物，发育出专门的器官，由不同类型的组织组成。器官的结构或模式由组织内的极性决定，例如径向或内外对称。当细胞具有方向感时，极性就建立起来了。虽然发育生物学家已经成功地确定了指定器官单个细胞类型所需的基因，甚至它们在遗传网络中如何相互作用，但我们对调节组织极性的机制知之甚少。开花植物大约在1.4亿年前进化而成，今天占植物界90%以上的植物。它们取得巨大成功的主要原因是果实的发育，果实是包含发育中的种子的生殖器官。受精后，果实滋养，保护和调解种子的有效传播，以确保后代的成功。果实的形状和大小各不相同，但所有果实的共同点是它们都是从花中心的心皮结构发展而来的，心皮融合形成雌蕊群。有趣的是，德国诗人和科学家约翰·沃尔夫冈·冯·歌德在200多年前提出假设，所有的花器官实际上都是经过改造的叶子。现代遗传学和分子生物学证实了歌德的预测，并揭示了心皮也是从叶进化而来的。因此，雌蕊群从一个简单的基本计划形成，并随着时间的推移进行修改，以优化其作为生殖器官的功能。例如，这些修饰允许在雌蕊群中心的子房中发育胚珠，这些胚珠将受精以发育种子。它们还负责在雌蕊顶端产生一种称为柱头的结构，以促进授粉，并且修饰还导致在柱头下方形成花柱，以支持花粉管的发育，这将引导花粉到胚珠以进行有效的受精。子房呈内外对称，反映了两片融合叶的起源，花柱和柱头呈放射状对称。从两片叶子中产生雌蕊群所涉及的修改，因此涉及改变组织的极性。激素等移动的信号可能协调雌蕊群中不同区域和结构的生长。我们最近的研究表明，植物激素生长素具有如此突出的作用。在这项提案中，我们将建立在这些初步数据的基础上，并利用新开发的遗传和分子资源，数学建模以及DNA深度测序技术：1）了解一组已知的转录因子和生长素活性之间的相互作用如何调节特定组织的极性。2）确定由生长素/转录因子模块调节的途径和关键组分。3）研究生长素分布模式是如何建立的。通过这些研究，我们的目标是提供一个统一的理解组织极性建立在雌蕊发育过程中，并揭示生长素的关键重要性，使过渡从营养叶到一个复杂的生殖器官。

项目成果

Fruit shape diversity in the Brassicaceae is generated by varying patterns of anisotropy.

• DOI: 10.1242/dev.135327
• 发表时间: 2016-09-15
• 期刊: Development (Cambridge, England)
• 作者: Eldridge T;Łangowski Ł;Stacey N;Jantzen F;Moubayidin L;Sicard A;Southam P;Kennaway R;Lenhard M;Coen ES;Østergaard L
• 通讯作者: Østergaard L

Gynoecium formation: an intimate and complicated relationship.

• DOI: 10.1016/j.gde.2017.02.005
• 发表时间: 2017-08
• 期刊: Current opinion in genetics & development
• 影响因子: 4
• 作者: Laila Moubayidin;L. Østergaard

Dynamic control of auxin distribution imposes a bilateral-to-radial symmetry switch during gynoecium development.

• DOI: 10.1016/j.cub.2014.09.080
• 发表时间: 2014-11-17
• 期刊: CURRENT BIOLOGY
• 影响因子: 9.2
• 作者: Moubayidin, Laila;Ostergaard, Lars
• 通讯作者: Ostergaard, Lars

Systems Biology Approach Pinpoints Minimum Requirements for Auxin Distribution during Fruit Opening.

系统生物学方法确定了果实开放期间生长素分布的最低要求。

• DOI: 10.1016/j.molp.2019.05.003
• 发表时间: 2019
• 期刊: Molecular plant
• 影响因子: 27.5
• 作者: Li XR

A noncanonical auxin-sensing mechanism is required for organ morphogenesis in Arabidopsis.

拟南芥中器官形态发生需要一种非规范的生长素感应机制。

• DOI: 10.1101/gad.285361.116
• 发表时间: 2016-10-15
• 期刊: Genes & development
• 影响因子: 10.5
• 作者: Simonini S;Deb J;Moubayidin L;Stephenson P;Valluru M;Freire-Rios A;Sorefan K;Weijers D;Friml J;Østergaard L
• 通讯作者: Østergaard L