Cell-type specific transcriptional networks in root xylem adjacent cell layers
Cell-type specific transcriptional networks in root xylem adjacent cell layers
复制标题
DOI：
10.1101/2022.02.04.479129
复制
发表时间：
2022-02
期刊：
影响因子：
--
通讯作者：
Maria Amparo Asensi Fabado;E. A. Armstrong;L. Walker;Giorgio Perrella;G. Hamilton;P. Herzyk;M. Gifford;A. Amtmann
中科院分区：
文献类型：
--
作者：
Maria Amparo Asensi Fabado;E. A. Armstrong;L. Walker;Giorgio Perrella;G. Hamilton;P. Herzyk;M. Gifford;A. Amtmann
水、离子和信号通过木质部管道从根到叶的运输是植物生命所必需的，需要严格调节。蒸腾流进入芽前的最终组成是由根上部木质部邻近的细胞层，即木质部薄壁和中柱鞘控制的。为了揭示这一重要位置的调控网络，我们生成了在HKT1启动子控制下表达核标签的拟南芥系。HKT1从木质部中回收钠，以防止茎部的毒性水平，这一功能取决于其在根上部木质部邻近组织中的特定表达。基于FACS rna测序和完好的chip测序，我们确定了在标记的细胞类型中优先表达的基因库，并发现了经历细胞类型特异性H3K27me3去甲基化损失的转录因子。对于其中之一的ZAT6，我们发现h3k27me3 -去甲基化酶REF6是去抑制所必需的。对zat6突变体的分析表明，zat6激活了一套细胞型特异性下游基因，限制了Na+在茎部的积累。这些组合文件为“自下而上”的细胞类型特异性调控网络的因果解剖提供了新的机会，这些调控网络在环境挑战下控制着根到芽的通信。
Transport of water, ions and signals from roots to leaves via the xylem vessels is essential for plant life and needs to be tightly regulated. The final composition of the transpiration stream before passage into the shoots is controlled by the xylem-adjacent cell layers, namely xylem parenchyma and pericycle, in the upper part of the root. To unravel regulatory networks in this strategically important location, we generated Arabidopsis lines expressing a nuclear tag under the control of the HKT1 promoter. HKT1 retrieves sodium from the xylem to prevent toxic levels in the shoot, and this function depends on its specific expression in upper root xylem-adjacent tissues. Based on FACS RNA-sequencing and INTACT ChIP-sequencing, we identified the gene repertoire that is preferentially expressed in the tagged cell types and discovered transcription factors experiencing cell-type specific loss of H3K27me3 demethylation. For one of these, ZAT6, we show that H3K27me3-demethylase REF6 is required for de-repression. Analysis of zat6 mutants revealed that ZAT6 activates a suite of cell-type specific downstream genes and restricts Na+ accumulation in the shoots. The combined Files open novel opportunities for ‘bottom-up’ causal dissection of cell-type specific regulatory networks that control root-to-shoot communication under environmental challenge.