Molecular Physiology of Endosperm-limited Seed Germination - Gene Function and Regulation in the Endosperm of Brassicaceae Species

胚乳限制种子萌发的分子生理学——十字花科物种胚乳的基因功能和调控

• 批准号: 20436173
• 负责人: Professor Dr. Gerhard Leubner
• 金额: --
• 依托单位: Plant Molecular Science
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/20436173?language=en
• 关键词: Molecular; Physiology; Endosperm; limited; Seed

The mature seeds of most angiosperm species are endospermic and in many cases the micropylar endosperm that covers the radicle is a mechanical constraint to embryo expansion and seed germination. We have shown by cross-species work with Lepidium sativum (Lepidium, big seeds) and Arabidopsis that endosperm weakening is an important trait of these Brassicaceae species. We have used seed-tissue-specific transcriptome analysis, genetic transformation, qRT-PCR, germination physiology, cell-wall biochemistry, reverse-genetics, and biomechanics to establish Lepidium as a model system for interdisciplinary seed research. Our new work plan includes as goals to identify and analyse tissue-specific promoters for reverse-genetics and superior housekeeping genes for qRT-PCR for seed research by utilizing our seed-tissue-specific transcriptome. We want to further optimize our reverse-genetics techniques for Lepidium seeds. Two tissue specific reverse-genetics approaches have the GA receptor GID1 (upstream, signaling) and pectin modifying enzymes as downstream mechanism for Lepidium endosperm weakening as targets. Pectin-mediated mechanism(s) belong to the late weakening mechanisms. Endosperm-specific cDNA libraries and tissue-specific cross-species transcriptome analysis at early time points will be used to identify early endosperm weakening targets. This project aims to deliver transgenic seeds altered in upstream and downstream mechanisms of endosperm weakening for functional and biomechanical analysis and will provide novel insight into endosperm function during seed germination.

大多数被子植物的成熟种子是胚乳的，在许多情况下，覆盖胚根的珠孔胚乳是胚扩展和种子萌发的机械限制。我们已经通过与独行菜（独行菜，大种子）和拟南芥的跨物种工作表明，胚乳弱化是这些拟南芥科物种的一个重要性状。我们使用种子组织特异性转录组分析、遗传转化、qRT-PCR、萌发生理学、细胞壁生物化学、反向遗传学和生物力学来建立独行菜作为跨学科种子研究的模型系统。我们的新工作计划包括利用我们的种子组织特异性转录组鉴定和分析用于反向遗传学的组织特异性启动子和用于种子研究的qRT-PCR的上级管家基因。我们希望进一步优化独行菜种子的反向遗传技术。两种组织特异性反向遗传学方法以GA受体GID 1（上游，信号传导）和果胶修饰酶作为独行菜胚乳弱化的下游机制作为靶标。果胶介导的机制属于后期弱化机制。胚乳特异性cDNA文库和早期时间点的组织特异性跨物种转录组分析将用于鉴定早期胚乳弱化靶标。该项目旨在提供改变胚乳弱化的上游和下游机制的转基因种子，用于功能和生物力学分析，并将提供种子萌发过程中胚乳功能的新见解。