Transcription factors (TFs) are essential for the regulation of gene expression and cell fate determination. Characterising the transcriptional activity of TF genes in space and time is a critical step towards understanding complex biological systems. The vegetative gametophyte meristems of bryophytes share some characteristics with the shoot apical meristems of flowering plants. However, the identity and expression profiles of TFs associated with gametophyte organization are largely unknown. With only ∼450 putative TF genes, Marchantia (Marchantia polymorpha) is an outstanding model system for plant systems biology. We have generated a near-complete collection of promoter elements derived from Marchantia TF genes. We experimentally tested reporter fusions for all the TF promoters in the collection and systematically analysed expression patterns in Marchantia gemmae. This allowed us to build a map of expression domains in early vegetative development and identify a set of TF-derived promoters that are active in the stem cell zone. The cell markers provide additional tools and insight into the dynamic regulation of the gametophytic meristem and its evolution. In addition, we provide an online database of expression patterns for all promoters in the collection. We expect that these promoter elements will be useful for cell-type-specific expression, synthetic biology applications, and functional genomics.

中文翻译：

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地钱营养发育过程中转录因子启动子活性的景观

转录因子 (TF) 对于基因表达的调节和细胞命运的决定至关重要。表征 TF 基因在空间和时间上的转录活性是理解复杂生物系统的关键一步。苔藓植物的营养配子体分生组织与开花植物的茎尖分生组织具有一些共同特征。然而，与配子体组织相关的转录因子的身份和表达谱在很大程度上是未知的。地钱 (Marchantia polymorpha) 仅含有约 450 个推定的 TF 基因，是植物系统生物学的杰出模型系统。我们已经生成了来自地钱属 TF 基因的近乎完整的启动子元件集合。我们通过实验测试了集合中所有 TF 启动子的报告基因融合，并系统分析了地钱中的表达模式。这使我们能够构建早期营养发育中的表达域图谱，并鉴定出一组在干细胞区域活跃的 TF 衍生启动子。细胞标记为配子体分生组织及其进化的动态调节提供了额外的工具和见解。此外，我们还提供了集合中所有启动子表达模式的在线数据库。我们预计这些启动子元件将可用于细胞类型特异性表达、合成生物学应用和功能基因组学。