A role for salicylic acid and NPR1 in regulating cell growth in Arabidopsis

Plant J. 2001 Oct;28(2):209-16. doi: 10.1046/j.1365-313x.2001.01158.x.


Salicylic acid (SA) plays a key role in activating defenses and cell death during plant-pathogen interactions. In response to some pathogens, SA also limits the extent of cell death, indicating that it acts positively or negatively depending on the host-pathogen interaction. In addition, we previously showed that SA affects cell growth in the Arabidopsis defense-related mutants accelerated cell death 6-1 (acd6-1) and aberrant growth and death 2 (agd2). Using acd6-1, agd2 and two other defense-related mutants, lesion simulating disease 6 (lsd6), suppressor of SA-insensitivity (ssi1), we show here in detail that SA regulates cell growth by specifically affecting cell enlargement, endoreduplication and/or cell division. We find that SA can act either positively or negatively to regulate cell growth depending on the context in which signaling occurs. Additionally, Nonexpressor of PR 1 (NPR1), a key SA signaling protein important for regulating defenses and cell death, also acts to promote cell division and/or suppress endoreduplication during leaf development. We propose that SA interacts with multiple receptors or signaling pathways to control cellular alterations during normal development, pathogen attack and/or stress situations. We suggest that SA and NPR1 play broader roles in cell fate control than has previously been understood.

Publication types

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

MeSH terms

  • Arabidopsis / cytology
  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis / microbiology
  • Arabidopsis Proteins*
  • Cell Death / drug effects
  • Cell Death / physiology
  • Cell Division / drug effects
  • Cell Size / physiology
  • Crosses, Genetic
  • Mutation
  • Plant Proteins / metabolism*
  • Pseudomonas / physiology
  • Salicylic Acid / pharmacology*
  • Signal Transduction / drug effects


  • Arabidopsis Proteins
  • NPR1 protein, Arabidopsis
  • Plant Proteins
  • Salicylic Acid