Distinct identities of leaf phloem cells revealed by single cell transcriptomics.
Distinct identities of leaf phloem cells revealed by single cell transcriptomics.
复制标题
DOI：
10.1093/plcell/koaa060
复制
发表时间：
2021-05-05
期刊：
影响因子：
--
通讯作者：
Frommer WB
中科院分区：
文献类型：
--
作者：
Kim JY;Symeonidi E;Pang TY;Denyer T;Weidauer D;Bezrutczyk M;Miras M;Zöllner N;Hartwig T;Wudick MM;Lercher M;Chen LQ;Timmermans MCP;Frommer WB
叶片维管系统在溶质运移中起着关键作用。静脉由至少七种不同的细胞类型组成，在运输，代谢和信号传导中具有特定的作用。关于叶维管细胞，特别是韧皮薄壁组织（PP）知之甚少。PP流出蔗糖进入质外质作为韧皮部装载的基础，然而PP仅在显微镜下被表征。在这里，我们丰富了拟南芥叶片的维管细胞，以产生叶脉管系统的单细胞转录组图谱。我们确定了至少19个细胞簇，包括表皮，保卫细胞，水母，叶肉，和所有的维管细胞类型，并使用代谢途径分析，以确定其作用。包含PP细胞的簇富集转运蛋白，包括SWEET 11和SWEET 12蔗糖和UmamiT氨基酸外排载体。我们提供的证据表明，PP的发展发生独立于改变韧皮部的发展，韧皮部分化所需的转录因子。PP细胞具有不同于伴随细胞（CC）的氨基酸代谢活性的独特模式，解释了静脉中氨基酸的差异分布/代谢。维管簇的亲缘关系与静脉形态非常相似，除了CC与包括PP在内的其他维管细胞明显分离。总之，我们的单细胞RNA测序分析提供了广泛的信息到叶脉管系统和叶细胞类型的作用和关系。叶scRNA-seq分析提供了对叶维管细胞类型和关键资源的深入了解，以建立与离子、代谢物和信号运输相关的假设和策略。
The leaf vasculature plays a key role in solute translocation. Veins consist of at least seven distinct cell types, with specific roles in transport, metabolism, and signaling. Little is known about leaf vascular cells, in particular the phloem parenchyma (PP). PP effluxes sucrose into the apoplasm as a basis for phloem loading, yet PP has been characterized only microscopically. Here, we enriched vascular cells from Arabidopsis leaves to generate a single-cell transcriptome atlas of leaf vasculature. We identified at least 19 cell clusters, encompassing epidermis, guard cells, hydathodes, mesophyll, and all vascular cell types, and used metabolic pathway analysis to define their roles. Clusters comprising PP cells were enriched for transporters, including SWEET11 and SWEET12 sucrose and UmamiT amino acid efflux carriers. We provide evidence that PP development occurs independently from ALTERED PHLOEM DEVELOPMENT, a transcription factor required for phloem differentiation. PP cells have a unique pattern of amino acid metabolism activity distinct from companion cells (CCs), explaining differential distribution/metabolism of amino acids in veins. The kinship relation of the vascular clusters is strikingly similar to the vein morphology, except for a clear separation of CC from the other vascular cells including PP. In summary, our single-cell RNA-sequencing analysis provides a wide range of information into the leaf vasculature and the role and relationship of the leaf cell types. A leaf scRNA-seq analysis provides insight into leaf vascular cell types and critical resources to build hypotheses and strategies related to the transport of ions, metabolites, and signals.