Analysis of Xylem Cells by Nucleus-Based Transcriptomics and Chromatin Profiling.

Nuclei contain essential information for cell states, including chromatin and RNA profiles - features which are nowadays accessible using high-throughput sequencing applications. Here, we describe analytical pipelines including nucleus isolation from differentiated xylem tissues by fluorescence-activated nucleus sorting (FANS), as well as subsequent SMART-seq2-based transcriptome profiling and assay for transposase-accessible chromatin (ATAC)-seq-based chromatin analysis. Combined with tissue-specific expression of nuclear fluorescent reporters, these pipelines allow obtaining tissue-specific data on gene expression and on chromatin structure and are applicable for a large spectrum of cell types, tissues, and organs. Considering, however, the extreme degree of differentiation found in xylem cells with programmed cell death happening during vessel element formation and their role as a long-term depository for atmospheric CO in the form of wood, xylem cells represent intriguing and relevant objects for large-scale profilings of their cellular signatures.