Epigenetic reprogramming and non-cell autonomous communication as mechanisms of seed formation

表观遗传重编程和非细胞自主通讯作为种子形成的机制

• 批准号: 421178202
• 负责人: Dr. Duarte Figueiredo, Ph.D.
• 金额: --
• 依托单位: Department of BioSciences
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/421178202?language=en
• 关键词: Epigenetic; reprogramming; non; cell; autonomous

The ability to form seeds is a key factor that contributed to the ecological dominance of flowering plants. The development of a seed starts with the fertilization of the maternal gametes within the ovule, egg cell and central cell, by two paternal sperm cells. This leads to the formation of the embryo, which will originate a new plant, and of the endosperm, a nourishing tissue, analogous to the mammalian placenta. These two fertilization products are surrounded by a maternal tissue, called the seed coat, which is derived from the ovule integuments. During seed formation, these three structures, embryo, endosperm and seed coat, have to coordinate their development in order to ensure the successful transmission of the parental genomes to the next generation. Seeds, and seed endosperm in particular, comprise the majority of our food, as well as of animal feed. Nevertheless, we know surprisingly little about the molecular and genetic mechanisms that underlie the formation of a seed. This project aims to uncover those mechanisms that contribute to the formation of the endosperm and of the seed coat. The development of these two structures only starts after fertilization. This is because epigenetic mechanisms prevent the maternal ovule from forming a seed in the absence of fertilization. This also means that the paternal sperm cells carry signals that are responsible for initiating seed development. Previous work showed that the plant hormone auxin is produced after fertilization, in a paternal-dependent manner, and initiates endosperm and seed coat formation in the model plant species Arabidopsis thaliana. However, the mechanisms by which auxin bypasses the epigenetic repression of seed development remain unexplored. Furthermore, although auxin is sufficient to initiate seed development, it is not sufficient to sustain it, and additional factors seem to be required. This project aims at addressing these two questions. It will do so, first by searching for epigenetic "erasers" that may work with auxin in initiating seed coat development, and second by studying the role of another class of plant hormones, brassinosteroids, as potential signal molecules that are required for endosperm and seed coat communication. Finally, a genetic screen will be implemented to search for additional mechanisms that contribute to seed formation. This project thus aims at providing a better understanding of the molecular and genetic mechanisms that are necessary for seed formation. Consequently, this work is expected to be of interest for a wide audience, including plant developmental biologists, geneticists, and plant breeders.

形成种子的能力是开花植物生态优势的关键因素。种子的发育始于胚珠、卵细胞和中央细胞内的母系配子通过两个父系精细胞受精。这导致了胚胎和胚乳的形成，胚乳和胚乳的形成类似于哺乳动物的胎盘，胚乳是一种滋养组织。这两种受精产物被一种叫做种皮的母体组织所包围，种皮来自胚珠珠被。在种子形成过程中，胚胎、胚乳和种皮这三种结构必须协调发展，以确保亲本基因组成功传递给下一代。种子，特别是种子胚乳，构成了我们食物和动物饲料的大部分。然而，我们对种子形成的分子和遗传机制知之甚少，令人惊讶。该项目旨在揭示那些有助于胚乳和种皮形成的机制。这两种结构的发育只有在受精后才开始。这是因为表观遗传机制阻止母体胚珠在没有受精的情况下形成种子。这也意味着父系精子携带启动种子发育的信号。以前的工作表明，植物激素生长素在受精后以父本依赖的方式产生，并在模式植物拟南芥中启动胚乳和种皮的形成。然而，生长素绕过种子发育的表观遗传抑制的机制仍未被探索。此外，虽然生长素足以启动种子发育，但不足以维持它，似乎需要更多的因素。本项目旨在解决这两个问题。它将做到这一点，首先通过寻找在启动种皮发育过程中可能与生长素一起工作的表观遗传“橡皮”，其次通过研究另一类植物激素油菜素类固醇作为胚乳和种皮通讯所需的潜在信号分子所起的作用。最后，将实施遗传筛选，以寻找有助于种子形成的其他机制。因此，该项目旨在更好地了解种子形成所必需的分子和遗传机制。因此，这项工作预计会引起广大受众的兴趣，包括植物发育生物学家、遗传学家和植物育种者。