Laboratory of Biochemistry, Wageningen University, Stippeneng 4, Wageningen, 6708WE, The Netherlands.
Novosibirsk State University, LCT&EB, Novosibirsk, 630090, Russia.
Development. 2020 Apr 20;147(8):dev186130. doi: 10.1242/dev.186130.
Development of plant vascular tissues involves tissue identity specification, growth, pattern formation and cell-type differentiation. Although later developmental steps are understood in some detail, it is still largely unknown how the tissue is initially specified. We used the early embryo as a simple model to study this process. Using a large collection of marker genes, we found that vascular identity was specified in the 16-cell embryo. After a transient precursor state, however, there was no persistent uniform tissue identity. Auxin is intimately connected to vascular tissue development. We found that, although an AUXIN RESPONSE FACTOR5/MONOPTEROS (ARF5/MP)-dependent auxin response was required, it was not sufficient for tissue specification. We therefore used a large-scale enhanced yeast one-hybrid assay to identify potential regulators of vascular identity. Network and functional analysis of candidate regulators suggest that vascular identity is under robust, complex control. We found that one candidate regulator, the G-class bZIP transcription factor GBF2, can modulate vascular gene expression by tuning MP output through direct interaction. Our work uncovers components of a gene regulatory network that controls the initial specification of vascular tissue identity.
植物维管组织的发育涉及组织身份的指定、生长、模式形成和细胞类型分化。尽管人们对后期的发育步骤有了一些详细的了解，但组织最初是如何被指定的仍然很大程度上是未知的。我们使用早期胚胎作为一个简单的模型来研究这个过程。利用大量的标记基因，我们发现血管身份在 16 细胞胚胎中被指定。然而，在短暂的前体状态之后，没有持续的统一组织身份。生长素与维管组织的发育密切相关。我们发现，虽然需要一个依赖于 AUXIN RESPONSE FACTOR5/MONOPTEROS (ARF5/MP)的生长素反应，但它不足以指定组织身份。因此，我们使用了大规模的增强型酵母单杂交测定法来鉴定潜在的血管身份调控因子。候选调控因子的网络和功能分析表明，血管身份受到稳健、复杂的控制。我们发现，一个候选调控因子，即 G 类 bZIP 转录因子 GBF2，可以通过直接相互作用调节 MP 输出，从而调节血管基因的表达。我们的工作揭示了控制血管组织身份初始指定的基因调控网络的组成部分。
