Feedback communication between mother plant and embryo regulating early embryo development in Arabidopsis thaliana

合子的不对称分裂通过产生具有不同发育程序的两个子细胞来建立植物胚的顶基（茎-根）轴：顶端胚细胞和连接胚与母体植物的胚柄的基部前体。早期胚胎发育与周围的母体组织密切协调，但与动物不同的是，对调控早期胚胎模式的母体因素知之甚少。在第一个资助期间，我们发现了母体植物和胚胎之间的一种未知的反馈通信：受精向未来胚胎周围的母体孢子体珠被提供信号，以触发植物激素生长素的生物合成增加。这种上调反过来又需要向胚胎发出信号，并调节身体计划模式的早期步骤。除了我们公布的结果，我们已经获得了一些现有的新数据，这些数据构成了我们在第二个资助期内研究的基础。例如，一个意想不到的结果是，非规范伊加生长素生物合成途径参与母体信号传导，与规范生长素生物合成平行。在第二个资助期内，我们将测试我们在第一个资助期工作中提出的特定假设，并进行突变筛查和新的单细胞测序，以阐明母体和胚胎通讯的分子机制。除了提供深入了解植物发育的一个基本问题，该项目的结果有可能有助于改善植物育种的再生策略。

The asymmetric division of the zygote establishes the apical-basal (shoot-root) axis of the plant embryo by generating two daughter cells with different developmental programs: an apical embryonic cell and a basal precursor of the suspensor, which connects the embryo with the mother plant. Early embryo development is tightly coordinated with surrounding maternal tissues, but unlike in animals, little is known yet about maternal factors regulating early embryo patterning. During the first funding period, we discovered a yet unknown feedback communication between the mother plant and the embryo: Fertilization provides a signal to the maternal sporophytic integuments that surround the future embryo to trigger increased biosynthesis of the plant hormone auxin. This upregulation in turn is required to signal back to the embryo and to regulate early steps in body plan patterning. In addition to our published results, we have already obtained several exiting new data which form the basis for our studies during the second funding period, applied here for. One unexpected result, for example, is that the non-canonical IGA auxin biosynthesis pathway is involved in maternal signaling, in parallel to canonical auxin biosynthesis. During the second funding period, we will test specific hypothesis that originated from our work in the first funding period, together with performing a mutant screen and a novel single-cell sequencing to elucidate the molecular mechanisms of maternal and embryonic communication. In addition to providing insight into a fundamental question of plant development, the results of this project have the potential to contribute to improved regeneration strategies in plant breeding.