Secondary messengers and phospholipase A2 in auxin signal transduction

Plant Mol Biol. Jun-Jul 2002;49(3-4):357-72.


Despite recent progress auxin signal transduction remains largely scetchy and enigmatic. A good body of evidence supports the notion that the ABP1 could be a functional receptor or part of a receptor, respectively, but this is not generally accepted. Evidence for other functional receptors is lacking, as is any clearcut evidence for a function of G proteins. Protons may serve as second messengers in guard cells but the existing evidence for a role of calcium remains to be clearified. Phospholipases C and D seem not to have a function in auxin signal transduction whereas the indications for a role of phospholipase A2 in auxin signal transduction accumulated recently. Mitogen-activated protein kinase (MAPK) is modulated by auxin and the protein kinase PINOID has a role in auxin transport modulation even though their functional linkage to other signalling molecules is ill-defined. It is hypothesized that signal transduction precedes activation of early genes such as IAA genes and that ubiquitination and the proteasome are a mechanism to integrate signal duration and signal strength in plants and act as major regulators of hormone sensitivity.

Publication types

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

MeSH terms

  • Arabidopsis Proteins*
  • Biological Transport
  • Gene Expression Regulation, Plant / drug effects
  • Indoleacetic Acids / metabolism
  • Indoleacetic Acids / pharmacology*
  • Phospholipases A / metabolism*
  • Phospholipases A2
  • Plant Growth Regulators*
  • Plant Proteins*
  • Plants / drug effects
  • Plants / genetics
  • Plants / metabolism
  • Protein-Serine-Threonine Kinases / physiology
  • Receptors, Cell Surface / physiology
  • Second Messenger Systems / physiology*
  • Signal Transduction*


  • Arabidopsis Proteins
  • Indoleacetic Acids
  • Plant Growth Regulators
  • Plant Proteins
  • Receptors, Cell Surface
  • auxin receptor, plant
  • PINOID protein, Arabidopsis
  • Protein-Serine-Threonine Kinases
  • Phospholipases A
  • Phospholipases A2