title: A high-resolution gene expression map of the Arabidopsis shoot meristem stem cell niche.
abstract: The shoot apical meristem (SAM) acts as a reservoir for stem cells. The central zone (CZ) harbors stem cells. The stem cell progenitors differentiate in the adjacent peripheral zone and in the rib meristem located just beneath the CZ. The SAM is further divided into distinct clonal layers: the L1 epidermal, L2 sub-epidermal and L3 layers. Collectively, SAMs are complex structures that consist of cells of different clonal origins that are organized into functional domains. By employing fluorescence-activated cell sorting, we have generated gene expression profiles of ten cell populations that belong to different clonal layers as well as domains along the central and peripheral axis. Our work reveals that cells in distinct clonal layers exhibit greater diversity in gene expression and greater transcriptional complexity than clonally related cell types in the central and peripheral axis. Assessment of molecular functions and biological processes reveals that epidermal cells express genes involved in pathogen defense: the L2 layer cells express genes involved in DNA repair pathways and telomere maintenance, and the L3 layers express transcripts involved in ion balance and salt tolerance besides photosynthesis. Strikingly, the stem cell-enriched transcriptome comprises very few hormone-responsive transcripts. In addition to providing insights into the expression profiles of hundreds of transcripts, the data presented here will act as a resource for reverse genetic analysis and will be useful in deciphering molecular pathways involved in cell type specification and their functions.
authors: Department of Botany and Plant Sciences, Center for Plant Cell Biology (CEPCEB), Institute of Integrative Genome Biology (IIGB), University of California, Riverside, CA 92521, USA Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali 140306, India ryadav@iisermohali.ac.in venug@ucr.edu.
authors: Ram Kishor
authors: RK
authors: Yadav
authors: Department of Botany and Plant Sciences, Center for Plant Cell Biology (CEPCEB), Institute of Integrative Genome Biology (IIGB), University of California, Riverside, CA 92521, USA.
authors: Montreh
authors: M
authors: Tavakkoli
authors: Department of Botany and Plant Sciences, Center for Plant Cell Biology (CEPCEB), Institute of Integrative Genome Biology (IIGB), University of California, Riverside, CA 92521, USA.
authors: Mingtang
authors: M
authors: Xie
authors: Department of Botany and Plant Sciences, Center for Plant Cell Biology (CEPCEB), Institute of Integrative Genome Biology (IIGB), University of California, Riverside, CA 92521, USA.
authors: Thomas
authors: T
authors: Girke
authors: Department of Botany and Plant Sciences, Center for Plant Cell Biology (CEPCEB), Institute of Integrative Genome Biology (IIGB), University of California, Riverside, CA 92521, USA ryadav@iisermohali.ac.in venug@ucr.edu.
authors: G Venugopala
authors: GV
authors: Reddy
mesh_terms: D000136:Acid-Base Equilibrium / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D002874:Chromosome Mapping; D004260:DNA Repair / Q000235:genetics; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D018519:Meristem / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D019441:Plant Epidermis / Q000166:cytology*; D018520:Plant Shoots / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D059505:Telomere Homeostasis / Q000235:genetics; D059467:Transcriptome / Q000235:genetics*
keywords: CLAVATA; Central zone; WUSCHEL