Matilla Angel J
Departamento de Biología Funcional (Área Fisiología Vegetal), Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Plants (Basel). 2020 Jun 1;9(6):705. doi: 10.3390/plants9060705.
The production of viable seeds is a key event in the life cycle of higher plants. Historically, abscisic acid (ABA) and gibberellin (GAs) were considered the main hormones that regulate seed formation. However, auxin has recently emerged as an essential player that modulates, in conjunction with ABA, different cellular processes involved in seed development as well as the induction, regulation and maintenance of primary dormancy (PD). This review examines and discusses the key role of auxin as a signaling molecule that coordinates seed life. The cellular machinery involved in the synthesis and transport of auxin, as well as their cellular and tissue compartmentalization, is crucial for the development of the endosperm and seed-coat. Thus, auxin is an essential compound involved in integuments development, and its transport from endosperm is regulated by AGAMOUS-LIKE62 (AGL62) whose transcript is specifically expressed in the endosperm. In addition, recent biochemical and genetic evidence supports the involvement of auxins in PD. In this process, the participation of the transcriptional regulator ABA INSENSITIVE3 (ABI3) is critical, revealing a cross-talk between auxin and ABA signaling. Future experimental aimed at advancing knowledge of the role of auxins in seed development and PD are also discussed.
有活力种子的产生是高等植物生命周期中的关键事件。历史上，脱落酸（ABA）和赤霉素（GAs）被认为是调节种子形成的主要激素。然而，生长素最近已成为一个重要角色，它与ABA一起调节种子发育过程中涉及的不同细胞过程，以及初级休眠（PD）的诱导、调节和维持。本综述研究并讨论了生长素作为协调种子生命的信号分子的关键作用。生长素的合成和运输所涉及的细胞机制，以及它们在细胞和组织中的区室化，对于胚乳和种皮的发育至关重要。因此，生长素是参与珠被发育的必需化合物，其从胚乳的运输受AGAMOUS-LIKE62（AGL62）调控，AGL62的转录本在胚乳中特异性表达。此外，最近的生化和遗传学证据支持生长素参与PD过程。在此过程中，转录调节因子ABA INSENSITIVE3（ABI3）的参与至关重要，这揭示了生长素和ABA信号之间的相互作用。本文还讨论了旨在推进对生长素在种子发育和PD中作用认识的未来实验。
