Insitut Jean-Pierre Bourgin (IJPB), INRA, AgroParisTech, CNRS, Université Paris-Saclay, INRA, Route de St-Cyr (RD10), 78026, Versailles Cedex, France.
POPS, Plateforme TranscriptOmique, Institute of Plant Sciences, Université Paris-Saclay, rue de Noetzlin, Plateau du Moulon, 91190, Gif-sur-Yvette, France.
BMC Genomics. 2017 Dec 29;18(1):998. doi: 10.1186/s12864-017-4391-1.
Totipotency is the ability of a cell to regenerate a whole organism. Plant somatic embryogenesis (SE) is a remarkable example of totipotency because somatic cells reverse differentiation, respond to an appropriate stimulus and initiate embryo development. Although SE is an ideal system to investigate de-differentiation and differentiation, we still lack a deep molecular understanding of the phenomenon due to experimental restraints.
We applied the INTACT method to specifically isolate the nuclei of those cells undergoing SE among the majority of non-embryogenic cells that make up a callus. We compared the transcriptome of embryogenic cells to the one of proliferating callus cells. Our analyses revealed that embryogenic cells are transcriptionally rather than metabolically active. Embryogenic cells shut off biochemical pathways involved in carbohydrate and lipid metabolism and activate the transcriptional machinery. Furthermore, we show how early in SE, ground tissue and leaf primordia specification are switched on before the specification of a shoot apical meristem.
This is the first attempt to specifically profile embryogenic cells among the different cell types that constitute plant in vitro tissue cultures. Our comparative analyses provide insights in the gene networks regulating SE and open new research avenues in the field of plant regeneration.
全能性是细胞再生整个生物体的能力。植物体细胞胚胎发生（SE）是全能性的一个显著例子，因为体细胞逆转分化，对适当的刺激做出反应并启动胚胎发育。尽管 SE 是研究去分化和分化的理想系统，但由于实验限制，我们仍然缺乏对该现象的深入分子理解。
我们应用 INTACT 方法，专门分离出在构成愈伤组织的大多数非胚胎性细胞中进行 SE 的那些细胞的核。我们比较了胚胎性细胞和增殖性愈伤组织细胞的转录组。我们的分析表明，胚胎性细胞在转录上而不是在代谢上活跃。胚胎性细胞关闭涉及碳水化合物和脂质代谢的生化途径，并激活转录机制。此外，我们展示了在 SE 早期，如何在茎尖分生组织的特化之前，启动地上组织和叶原基的特化。
这是首次尝试在构成植物体外组织培养的不同细胞类型中专门分析胚胎性细胞。我们的比较分析为调控 SE 的基因网络提供了深入的了解，并为植物再生领域开辟了新的研究途径。
