Abstract：
The leaf veins of higher plants contain a highly specialized vascular system comprised of xylem and phloem cells that transport water, organic compounds and mineral nutrients. The development of the vascular system is controlled by phytohormones that interact with complex transcriptional regulatory networks. Before the emergence of true leaves, the cotyledons of young seedlings perform photosynthesis that provides energy for the sustainable growth and survival of seedlings. However, the mechanisms underlying the early development of leaf veins in cotyledons are still not fully understood, in part due to the complex cellular composition of this tissue. To better understand the development of leaf veins, we analyzed 14 117 single cells from 3-day-old cotyledons using single-cell RNA sequencing. Based on gene expression patterns, we identified 10 clusters of cells and traced their developmental trajectories. We discovered multiple new marker genes and developmental features of leaf veins. The transcription factor networks of some cell types indicated potential roles of CYCLING DOF FACTOR 5 (CDF5) and REPRESSOR OF GA (RGA) in the early development and function of the leaf veins in cotyledons. These new findings lay a foundation for understanding the early developmental dynamics of cotyledon veins. The mechanisms underlying the early development of leaf veins in cotyledons are still not fully understood. In this study, we comprehensively characterized the early differentiation and development of leaf veins in 3-day-old cotyledons based on single-cell transcriptome analysis. We identified the cell types and novel marker genes of leaf veins and characterized the novel regulators of leaf vein.
摘要：
高等植物的叶脉含有高度专业化的维管系统，由木质部和韧皮部细胞组成，运输水，有机化合物和矿物质营养素。血管系统的发育受与复杂转录调节网络相互作用的植物激素控制。在真正的叶子出现之前，幼苗的子叶进行光合作用，为幼苗的可持续生长和生存提供能量。然而,子叶叶脉早期发育的机制仍未完全理解，部分是由于该组织的复杂细胞组成。为了更好地了解叶脉的发育，我们使用单细胞RNA测序分析了3日龄子叶的14117个单细胞.基于基因表达模式,我们确定了10个细胞簇，并追踪了它们的发育轨迹。我们发现了多个新的标记基因和叶脉的发育特征。某些细胞类型的转录因子网络表明循环DOF因子5（CDF5）和GA受体（RGA）在子叶叶脉的早期发育和功能中的潜在作用。这些新发现为理解子叶静脉的早期发育动力学奠定了基础。子叶叶脉早期发育的机制仍未完全了解。在这项研究中,我们根据单细胞转录组分析，全面表征了3日龄子叶中叶脉的早期分化和发育。我们鉴定了叶脉的细胞类型和新的标记基因，并表征了叶脉的新调节剂。
