A P-Loop NTPase Regulates Quiescent Center Cell Division and Distal Stem Cell Identity through the Regulation of ROS Homeostasis in Arabidopsis Root

PLoS Genet. 2016 Sep 1;12(9):e1006175. doi: 10.1371/journal.pgen.1006175. eCollection 2016 Sep.


Reactive oxygen species (ROS) are recognized as important regulators of cell division and differentiation. The Arabidopsis thaliana P-loop NTPase encoded by APP1 affects root stem cell niche identity through its control of local ROS homeostasis. The disruption of APP1 is accompanied by a reduction in ROS level, a rise in the rate of cell division in the quiescent center (QC) and the promotion of root distal stem cell (DSC) differentiation. Both the higher level of ROS induced in the app1 mutant by exposure to methyl viologen (MV), and treatment with hydrogen peroxide (H2O2) rescued the mutant phenotype, implying that both the increased rate of cell division in the QC and the enhancement in root DSC differentiation can be attributed to a low level of ROS. APP1 is expressed in the root apical meristem cell mitochondria, and its product is associated with ATP hydrolase activity. The key transcription factors, which are defining root distal stem niche, such as SCARECROW (SCR) and SHORT ROOT (SHR) are both significantly down-regulated at both the transcriptional and protein level in the app1 mutant, indicating that SHR and SCR are important downstream targets of APP1-regulated ROS signaling to control the identity of root QC and DSCs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminopeptidases / genetics*
  • Aminopeptidases / metabolism
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Cell Division
  • Gene Expression Regulation, Plant
  • Homeostasis*
  • Hydrogen Peroxide / pharmacology
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Meristem / cytology*
  • Meristem / genetics
  • Meristem / metabolism
  • Mitochondria / metabolism
  • Paraquat / pharmacology
  • Plant Roots / cytology
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Roots / metabolism
  • Reactive Oxygen Species / metabolism*
  • Signal Transduction
  • Transcription Factors / genetics
  • Transcription Factors / metabolism


  • Arabidopsis Proteins
  • Membrane Proteins
  • Reactive Oxygen Species
  • SCR protein, Arabidopsis
  • SHORT ROOT protein, Arabidopsis
  • Transcription Factors
  • Hydrogen Peroxide
  • ATAPP1 protein, Arabidopsis
  • Aminopeptidases
  • Paraquat

Grants and funding

This study is funded by grants from the National Basic Research Program of China (Grant No. 2015CB942900), the National Natural Science Foundation of China (Projects 31270327, 31470371 and 31570291), Shandong Provincial Funds for Distinguished Young Scholars (2014JQ201408).The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.