Mechanical Stress Acts via Katanin to Amplify Differences in Growth Rate Between Adjacent Cells in Arabidopsis

Cell. 2012 Apr 13;149(2):439-51. doi: 10.1016/j.cell.2012.02.048.

Abstract

The presence of diffuse morphogen gradients in tissues supports a view in which growth is locally homogenous. Here we challenge this view: we used a high-resolution quantitative approach to reveal significant growth variability among neighboring cells in the shoot apical meristem, the plant stem cell niche. This variability was strongly decreased in a mutant impaired in the microtubule-severing protein katanin. Major shape defects in the mutant could be related to a local decrease in growth heterogeneity. We show that katanin is required for the cell's competence to respond to the mechanical forces generated by growth. This provides the basis for a model in which microtubule dynamics allow the cell to respond efficiently to mechanical forces. This in turn can amplify local growth-rate gradients, yielding more heterogeneous growth and supporting morphogenesis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism*
  • Arabidopsis / cytology*
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Homeostasis
  • Katanin
  • Meristem / cytology*
  • Meristem / growth & development
  • Meristem / metabolism
  • Microtubules / metabolism
  • Models, Biological
  • Morphogenesis
  • Mutation
  • Plant Cells / physiology
  • Plant Shoots / cytology
  • Plant Shoots / growth & development
  • Stress, Mechanical

Substances

  • Arabidopsis Proteins
  • Adenosine Triphosphatases
  • KTN1 protein, Arabidopsis
  • Katanin