Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France.
Université Paris-Saclay, 91405 Orsay, France.
Int J Mol Sci. 2022 Oct 9;23(19):12007. doi: 10.3390/ijms231912007.
In plants, stem cells are embedded in structures called meristems. Meristems can be formed either during embryogenesis or during the plant's life such as, for instance, axillary meristems. While the regulation of the stem cell population in an established meristem is well described, how it is initiated in newly formed meristems is less well understood. Recently, two transcription factors of the NGATHA-like family, DEVELOPMENT-RELATED PcG TARGET IN THE APEX4 (DPA4)/NGAL3 and SUPPRESSOR OF DA1-1 7 (SOD7)/NGAL2 have been shown to facilitate de novo stem cell initiation in axillary meristems. Here, we tested whether the and genes had a similar role during stem cell formation in embryo shoot apical meristems. Using and reporter lines, we characterized the expression pattern of these genes during embryo development, revealing only a partial overlap with the stem cell population. In addition, we showed that the expression of a stem cell reporter was not modified in double mutant embryos compared to the wild type. Together, these observations suggest that and are not required for stem cell specification during embryo shoot apical meristem initiation. This work stresses the difference in the regulatory network leading to meristem formation during the embryonic and post-embryonic phases.
在植物中，干细胞嵌入在称为分生组织的结构中。分生组织可以在胚胎发生期间或植物的生命过程中形成，例如腋生分生组织。虽然已建立的分生组织中干细胞群体的调节已得到很好的描述，但在新形成的分生组织中如何启动它还不太清楚。最近，两个 NGATHA 样家族的转录因子，发育相关 PcG TARGET IN THE APEX4（DPA4）/NGAL3 和 SUPPRESSOR OF DA1-1 7（SOD7）/NGAL2，已被证明有助于腋生分生组织中新生干细胞的起始。在这里，我们测试了 和 基因在胚胎茎尖分生组织中形成干细胞时是否具有类似的作用。使用 和 报告基因系，我们描述了这些基因在胚胎发育过程中的表达模式，仅与干细胞群体有部分重叠。此外，我们表明与野生型相比，在 双突变体胚胎中干细胞报告基因的表达没有改变。总之，这些观察结果表明， 和 对于胚胎茎尖分生组织起始过程中的干细胞特化不是必需的。这项工作强调了在胚胎和胚胎后阶段导致分生组织形成的调控网络的差异。
