Abstract：
Apical hook is a simple curved structure formed at the upper part of hypocotyls when dicot seeds germinate in darkness. The hook structure is transient but essential for seedlings\' survival during soil emergence due to its efficient protection of the delicate shoot apex from mechanical injury. As a superb model system for studying plant differential growth, apical hook has fascinated botanists as early as the Darwin age, and significant advances have been achieved at both the morphological and molecular levels to understand how apical hook development is regulated. Here, we will mainly summarize the research progress at these two levels. We will also briefly compare the growth dynamics between apical hook and hypocotyl gravitropic bending at early seed germination phase, with the aim to deduce a certain consensus on their connections. Finally, we will outline the remaining questions and future research perspectives for apical hook development.
摘要：
根尖钩是双子叶种子在黑暗中发芽时在下胚轴上部形成的简单弯曲结构。钩结构是短暂的，但对于幼苗在土壤出苗期间的生存至关重要，因为它有效地保护了脆弱的茎尖免受机械伤害。作为研究植物差异生长的极好模型系统，根尖钩早在达尔文时代就吸引了植物学家，并且在形态和分子水平上都取得了重大进展，以了解根尖钩发育是如何调节的。这里,我们将主要总结这两个方面的研究进展。我们还将简要比较种子萌发初期顶端钩和下胚轴重力弯曲之间的生长动力学，目的是就他们之间的联系达成某种共识。最后,我们将概述根尖钩发育的剩余问题和未来研究前景。本文受版权保护。保留所有权利。
