Photoperiod-responsive changes in chromatin accessibility in phloem companion and epidermis cells of Arabidopsis leaves
Photoperiod-responsive changes in chromatin accessibility in phloem companion and epidermis cells of Arabidopsis leaves
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拟南芥叶韧皮部伴细胞和表皮细胞染色质可及性的光周期响应变化
DOI：
10.1093/plcell/koaa043
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发表时间：
2021-01-04
期刊：
影响因子：
11.6
通讯作者：
Liu, Liangyu
中科院分区：
文献类型：
--
作者：
Tian, Hao;Li, Yuru;Liu, Liangyu
光周期在控制开花植物从营养生长到生殖生长的相变中起着关键作用。叶子是感知日长信号的主要器官，但特定的叶子细胞类型如何响应光周期仍然未知。我们通过将特定细胞/组织类型中标记的细胞核分离与使用测序和 RNA 测序进行转座酶可及染色质测定相结合，整合了拟南芥叶表皮和维管伴细胞中的光周期响应染色质可及性和转录组数据。尽管有很大的重叠，但脉管系统和表皮细胞的反应不同。长日照显着诱导可及染色质区域（ACR）；在脉管系统中，与表皮相比，诱导了更多的 ACR，并且这些 ACR 位于更远端的基因区域。长日照诱导的血管 ACR 在开花相关转录因子的结合位点上高度富集。在排名靠前的基因中（基于脉管系统中的染色质和表达特征），我们将海藻糖磷酸酶/合成酶 9 (TPS9) 鉴定为开花激活剂，如 T-DNA 插入突变体和韧皮部特异性敲低 TPS9 的转基因品系的晚花表型所示。我们的细胞类型特异性分析揭示了长日光周期刺激如何以组织特异性方式影响染色质可及性以调节植物发育。
Photoperiod plays a key role in controlling the phase transition from vegetative to reproductive growth in flowering plants. Leaves are the major organs perceiving day-length signals, but how specific leaf cell types respond to photoperiod remains unknown. We integrated photoperiod-responsive chromatin accessibility and transcriptome data in leaf epidermis and vascular companion cells of Arabidopsis thaliana by combining isolation of nuclei tagged in specific cell/tissue types with assay for transposase-accessible chromatin using sequencing and RNA-sequencing. Despite a large overlap, vasculature and epidermis cells responded differently. Long-day predominantly induced accessible chromatin regions (ACRs); in the vasculature, more ACRs were induced and these were located at more distal gene regions, compared with the epidermis. Vascular ACRs induced by long days were highly enriched in binding sites for flowering-related transcription factors. Among the highly ranked genes (based on chromatin and expression signatures in the vasculature), we identified TREHALOSE-PHOSPHATASE/SYNTHASE 9 (TPS9) as a flowering activator, as shown by the late flowering phenotypes of T-DNA insertion mutants and transgenic lines with phloem-specific knockdown of TPS9. Our cell-type-specific analysis sheds light on how the long-day photoperiod stimulus impacts chromatin accessibility in a tissue-specific manner to regulate plant development.