生长素在植物胚胎早期发育中的作用

有性生殖是有花植物的一个重要特征, 胚胎则是实现有性生殖和世代交替的重要载体。植物胚胎从双受精开始, 经历了合子极性建立、顶基轴形成、细胞层分化和器官形成等过程, 这些过程都受到生长素的调控。近年来的研究表明, 生长素在生物合成、极性运输和信号转导3个层面上调控胚胎的发育过程。该文以双子叶植物拟南芥(Arabidopsis thaliana)为例, 综述了生长素对胚胎早期发育过程, 包括合子极性和顶基轴建立、表皮原特化和对称模式转变、胚根原特化和根尖分生组织形成及茎尖分生组织形成等发育的调控机制。

Role of Auxin in Early Embryogenesis of Plants

A hallmark of flowering plants is sexual reproduction, with the embryo a key player. In double fertilization, the zygote (fertilized egg) first establishes its apical-basal polarity within the single cell. With cell division and differentiation, the proembryo forms a apical-basal axis and develops through pattern formation and organogenesis. Recent advances have shown that the whole process of embryogenesis is regulated by auxin at levels of biosynthesis, polar transport and signal transduction. In this review, we highlight our current understanding, mainly from studies in Arabidopsis, of the molecular mechanisms by which auxin controls embryogenesis. These mechanisms include the establishment of polarity of zygotes, apical-basal axis of embryos, differentiation of protoderm, transition of radial symmetry to bilateral symmetry, formation of hypophysis, shoot apical meristem and root apical meristem. In addition, we briefly introduce the embryogenesis process not regulated by auxin.