Arabidopsis LEAFY COTYLEDON2 induces maturation traits and auxin activity:: Implications for somatic embryogenesis
Arabidopsis LEAFY COTYLEDON2 induces maturation traits and auxin activity:: Implications for somatic embryogenesis
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DOI：
10.1073/pnas.0712364105
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发表时间：
2008-02-26
影响因子：
11.1
通讯作者：
Harada, John J.
中科院分区：
文献类型：
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作者：
Stone, Sandra L.;Braybrook, Siobhan A.;Harada, John J.
LEAFY COTYLEDON2(LEC2)是胚胎发生的中央调控因子，在异位表达时足以诱导体细胞形成胚胎。在这里，我们分析了B3结构域转录因子LEC2诱导的细胞过程，这可能是其促进体细胞胚胎发生的能力的基础。我们发现生长素反应基因在LEC2激活后在幼苗中被诱导。编码生长素生物合成酶YUC2和YUC4的基因在LEC2活性诱导后1小时内被激活，YUC4似乎是LEC2的直接转录靶点。我们还发现，异源LEC2的表达诱导了营养器官和生殖器官中种子贮藏蛋白和油体的积累，这些事件通常发生在胚胎发育的成熟期。此外，在观察到编码LEC1或FUS3的RNA增加之前，LEC2激活了种子蛋白基因。因此，LEC2引起生长素反应的快速变化，并诱导成熟阶段的细胞分化特征。讨论了这些变化与LEC2促进体细胞胚胎发生的能力之间的关系。
LEAFY COTYLEDON2 (LEC2) is a central regulator of embryogenesis sufficient to induce somatic cells to form embryos when expressed ectopically. Here, we analyze the cellular processes induced by LEC2, a B3 domain transcription factor, that may underlie its ability to promote somatic embryogenesis. We show auxin-responsive genes are induced after LEC2 activation in seedlings. Genes encoding enzymes involved in auxin biosynthesis, YUC2 and YUC4, are activated within 1 h after induction of LEC2 activity, and YUC4 appears to be a direct transcriptional target of LEC2. We also show ectopic LEC2 expression induces accumulation of seed storage protein and oil bodies in vegetative and reproductive organs, events that normally occur during the maturation phase of embryogenesis. Furthermore, LEC2 activates seed protein genes before an increase in RNAs encoding LEC1 or FUS3 is observed. Thus, LEC2 causes rapid changes in auxin responses and induces cellular differentiation characteristic of the maturation phase. The relevance of these changes to the ability of LEC2 to promote somatic embryogenesis is discussed.