Gibberellins play an essential role in late embryogenesis of Arabidopsis
Gibberellins play an essential role in late embryogenesis of Arabidopsis
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赤霉素在拟南芥晚期胚胎发生中发挥重要作用
DOI：
10.1038/s41477-018-0143-8
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发表时间：
2018-05-01
期刊：
影响因子：
18
通讯作者：
Hou, Xingliang
中科院分区：
文献类型：
--
作者：
Hu, Yilong;Zhou, Limeng;Hou, Xingliang
植物激素赤霉素在植物发育的几乎所有方面都起着关键作用，但其在胚胎发育中的详细功能和潜在调控机制尚未明确。在这里，我们说明了赤霉素在拟南芥胚胎发生后期的重要作用。生物活性赤霉素在胚胎发育后期高度生物合成。此时，赤霉素生物合成或信号传导的缺陷导致异常胚表型，其特征在于不太发育的子叶和缩短的胚轴。相反，过量的赤霉素导致成熟胚的显著更大的尺寸。我们揭示了赤霉素信号抑制子DELLA与叶子叶1（LEC 1），在胚胎发生后期的关键调节相互作用。赤霉素触发DELLA的降解以解除其对LEC 1的抑制，从而促进生长素的积累以促进胚胎发育。因此，我们揭示了空间/时间特异性的作用，赤霉素在调节后期胚胎发生通过赤霉素DELLA-LEC 1信号级联，提供了一个新的机制的理解植物激素如何调节胚胎发生。
The plant hormone gibberellin plays key roles in almost all aspects of plant development, but its detailed function and underlying regulatory mechanism in embryo development are not yet clearly defined. Here, we illustrate an essential role of gibberellin in late embryogenesis of Arabidopsis. Bioactive gibberellins are highly biosynthesized during the late developmental stage of embryos. At that time, deficiency in gibberellin biosynthesis or signalling results in an abnormal embryo phenotype characterized by less-developed cotyledons and shortened embryo axis. In contrast, gibberellin overdose leads to a significantly larger size of mature embryo. We reveal that the gibberellin signalling repressor DELLA interact with LEAFY COTYLEDON1 (LEC1), the key regulator in late embryogenesis. Gibberellin triggers the degradation of DELLAs to relieve their repression of LEC1, thus promoting auxin accumulation to facilitate embryo development. Therefore, we uncover a space/time-specific role of gibberellin in regulating late embryogenesis through the gibberellin-DELLA-LEC1 signalling cascade, providing a novel mechanistic understanding of how phytohormones regulate embryogenesis.