AtDEK1 is essential for specification of embryonic epidermal cell fate
AtDEK1 is essential for specification of embryonic epidermal cell fate
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DOI：
10.1111/j.1365-313x.2005.02514.x
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发表时间：
2005-10-01
期刊：
影响因子：
7.2
通讯作者：
Ingram, GC
中科院分区：
文献类型：
--
作者：
Johnson, KL;Degnan, KA;Ingram, GC
表皮(L1)特性的指定在植物胚胎发生的早期就开始了。在这里，我们表明，在拟南芥中，AtDEK1编码胚胎L1细胞层规范通路的关键成分。AtDEK1功能的丧失会导致早期胚胎死亡，其特征是胚胎中的细胞组织严重丧失，胚柄中的细胞分裂异常。L1标志ACR4和ATML1在纯合子突变胚胎中不表达。为了进一步阐明AtDEK1的功能，我们使用了RNAi敲除方法。这使得胚胎在失去AtDEK1活性之前部分完成了胚胎发生。由此产生的幼苗在很大一部分子叶中表现出特殊的表皮细胞特性的丧失。此外，分生组织的结构和功能系统地减少或完全丧失。在发育的任何阶段，AtDEK1的表达并不局限于L1表皮细胞层。这与AtDEK1在持续产生或解释表皮指定所需的位置信息方面发挥的上游作用是一致的。我们的结果不仅确定了AtDEK1在胚胎发生中的特定作用，而且强调了L1规范在球状阶段对随后的胚胎发生进展的潜在关键重要性。
The specification of epidermal (L1) identity occurs early during plant embryogenesis. Here we show that, in Arabidopsis, AtDEK1 encodes a key component of the embryonic L1 cell-layer specification pathway. Loss of AtDEK1 function leads to early embryo lethality characterized by a severe loss of cell organization in the embryo proper and abnormal cell divisions within the suspensor. Markers for L1 identity, ACR4 and ATML1, are not expressed in homozygous mutant embryos. In order to clarify the function of AtDEK1 further, an RNAi knockdown approach was used. This allowed embryos to partially complete embryogenesis before losing AtDEK1 activity. Resulting seedlings showed a specific loss of epidermal cell identity within large portions of the cotyledons. In addition, meristem structure and function was systematically either reduced or entirely lost. AtDEK1 expression is not restricted to the L1 epidermal cell layer at any stage in development. This is consistent with AtDEK1 playing an upstream role in the continuous generation or interpretation of positional information required for epidermal specification. Our results not only identify a specific role for AtDEK1 during embryogenesis, but underline the potential key importance of L1 specification at the globular stage for subsequent progression through embryogenesis.