In Chinese cabbage development the interplay between shoot apex activity and vernalization is pivotal for flowering timing. The intricate relationship between various cell types in the shoot apex meristem and their roles in regulating flowering gene expression in Chinese cabbage is not yet fully understood. A thorough analysis of single-cell types in the Chinese cabbage shoot apex and their influence on flowering genes and vernalization is essential for deeper insight. Our study first established a single-cell transcriptomic atlas of Chinese cabbage after 25 days of non-vernalization. Analyzing 19 602 single cells, we differentiated them into 15 distinct cell clusters using established marker genes. We found that key genes in shoot apex development and flowering were primarily present in shoot meristematic cells (SMCs), companion cells (CCs), and mesophyll cells (MCs). MADS-box protein FLOWERING LOCUS C 2 (BrFLC2), a gene suppressing flowering, was observed in CCs, mirroring patterns found in Arabidopsis. By mapping developmental trajectories of SMCs, CCs, and MCs, we elucidated the evolutionary pathways of crucial genes in shoot apex development and flowering. The creation of a single-cell transcriptional atlas of the Chinese cabbage shoot apex under vernalization revealed distinct alterations in the expression of known flowering genes, such as VERNALIZATION INSENSITIVE 3 (VIN3), VERNALIZATION 1 (VRN1), VERNALIZATION 2 (VRN2), BrFLC, and FLOWERING LOCUS T (FT), which varied by cell type. Our study underscores the transformative impact of single-cell RNA sequencing (scRNA-seq) for unraveling the complex differentiation and vernalization processes in the Chinese cabbage shoot apex. These insights are pivotal for enhancing breeding strategies and cultivation management of this vital vegetable.

中文翻译：

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大白菜顶端开花调控和春化的单细胞转录组学分析


在大白菜的发育中，梢尖活动和春化之间的相互作用对开花时间至关重要。地上部顶端分生组织中各种细胞类型之间的复杂关系及其在调节大白菜开花基因表达中的作用尚不完全清楚。全面分析大白菜芽顶端的单细胞类型及其对开花基因和春化的影响对于更深入的了解至关重要。我们的研究首先建立了大白菜未春化 25 天后的单细胞转录组图谱。分析了 19 602 个单细胞，我们使用已建立的标记基因将它们分化为 15 个不同的细胞簇。我们发现，芽顶端发育和开花的关键基因主要存在于芽分生细胞 （SMC） 、伴侣细胞 （CC） 和叶肉细胞 （MCs） 中。MADS-box 蛋白开花基因座 C 2 （BrFLC2） 是一种抑制开花的基因，在 CCs 中观察到，与拟南芥中发现的模式相同。通过绘制 SMCs 、 CCs 和 MCs 的发育轨迹，我们阐明了茎尖发育和开花中关键基因的进化途径。在春化作用下创建大白菜芽顶端的单细胞转录图谱揭示了已知开花基因表达的明显变化，例如 VERNALIZATION INSENSITIVE 3 （VIN3）、VERNALIZATION 1 （VRN1）、VERNALIZATION 2 （VRN2）、BrFLC 和 FLOWERING LOCUS T （FT），它们因细胞类型而异。我们的研究强调了单细胞 RNA 测序 （scRNA-seq） 对揭示大白菜芽顶端复杂分化和春化过程的变革性影响。 这些见解对于加强这种重要蔬菜的育种策略和栽培管理至关重要。