Local auxin production underlies a spatially restricted neighbor-detection response in Arabidopsis

Proc Natl Acad Sci U S A. 2017 Jul 11;114(28):7444-7449. doi: 10.1073/pnas.1702276114. Epub 2017 Jun 26.


Competition for light triggers numerous developmental adaptations known as the "shade-avoidance syndrome" (SAS). Important molecular events underlying specific SAS responses have been identified. However, in natural environments light is often heterogeneous, and it is currently unknown how shading affecting part of a plant leads to local responses. To study this question, we analyzed upwards leaf movement (hyponasty), a rapid adaptation to neighbor proximity, in Arabidopsis We show that manipulation of the light environment at the leaf tip triggers a hyponastic response that is restricted to the treated leaf. This response is mediated by auxin synthesized in the blade and transported to the petiole. Our results suggest that a strong auxin response in the vasculature of the treated leaf and auxin signaling in the epidermis mediate leaf elevation. Moreover, the analysis of an auxin-signaling mutant reveals signaling bifurcation in the control of petiole elongation versus hyponasty. Our work identifies a mechanism for a local shade response that may pertain to other plant adaptations to heterogeneous environments.

Keywords: PIF; auxin; hyponasty; neighbor detection; organ-specific response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / physiology*
  • Arabidopsis Proteins / metabolism
  • Cryptochromes / metabolism
  • Gene Expression Regulation, Plant
  • Indoleacetic Acids / metabolism*
  • Light
  • Mutation
  • Peptides / chemistry
  • Plant Leaves / metabolism
  • Signal Transduction


  • Arabidopsis Proteins
  • Cryptochromes
  • Indoleacetic Acids
  • Peptides