Molecular Mechanisms Driving Switch Behavior in Xylem Cell Differentiation

Gina M Turco; Joel Rodriguez-Medina; Stefan Siebert; Diane Han; Miguel Á Valderrama-Gómez; Hannah Vahldick; Christine N Shulse; Benjamin J Cole; Celina E Juliano; Diane E Dickel; Michael A Savageau; Siobhan M Brady

doi:10.1016/j.celrep.2019.06.041

Molecular Mechanisms Driving Switch Behavior in Xylem Cell Differentiation

Cell Rep. 2019 Jul 9;28(2):342-351.e4. doi: 10.1016/j.celrep.2019.06.041.

Affiliations

¹ Department of Plant Biology and Genome Center, University of California, Davis, Davis, CA 95616, USA.
² Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA.
³ Department of Microbiology & Molecular Genetics, University of California, Davis, Davis, CA 95616, USA.
⁴ Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA.
⁵ Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
⁶ Department of Microbiology & Molecular Genetics, University of California, Davis, Davis, CA 95616, USA; Department of Biomedical Engineering, University of California, Davis, Davis, CA 95616, USA.
⁷ Department of Plant Biology and Genome Center, University of California, Davis, Davis, CA 95616, USA. Electronic address: sbrady@ucdavis.edu.

PMID: 31291572
DOI: 10.1016/j.celrep.2019.06.041

Abstract

Plant xylem cells conduct water and mineral nutrients. Although most plant cells are totipotent, xylem cells are unusual and undergo terminal differentiation. Many genes regulating this process are well characterized, including the Vascular-related NAC Domain 7 (VND7), MYB46, and MYB83 transcription factors, which are proposed to act in interconnected feedforward loops (FFLs). Less is known regarding the molecular mechanisms underlying the terminal transition to xylem cell differentiation. Here, we generate whole-root and single-cell data, which demonstrate that VND7 initiates sharp switching of root cells to xylem cell identity. Based on these data, we identified 4 candidate VND7 downstream target genes capable of generating this switch. Although MYB46 responds to VND7 induction, it is not among these targets. This system provides an important model to study the emergent properties that may give rise to totipotency relative to terminal differentiation and reveals xylem cell subtypes.

Keywords: differentiation; single cell; switch; totipotent; xylem.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Cell Differentiation
Plants
Transcriptional Activation / physiology*
Xylem / metabolism*

Grants and funding

55108506/HHMI/Howard Hughes Medical Institute/United States