A special pair of phytohormones controls excitability, slow closure, and external stomach formation in the Venus flytrap

Proc Natl Acad Sci U S A. 2011 Sep 13;108(37):15492-7. doi: 10.1073/pnas.1112535108. Epub 2011 Sep 6.

Abstract

Venus flytrap's leaves can catch an insect in a fraction of a second. Since the time of Charles Darwin, scientists have struggled to understand the sensory biology and biomechanics of this plant, Dionaea muscipula. Here we show that insect-capture of Dionaea traps is modulated by the phytohormone abscisic acid (ABA) and jasmonates. Water-stressed Dionaea, as well as those exposed to the drought-stress hormone ABA, are less sensitive to mechanical stimulation. In contrast, application of 12-oxo-phytodienoic acid (OPDA), a precursor of the phytohormone jasmonic acid (JA), the methyl ester of JA (Me-JA), and coronatine (COR), the molecular mimic of the isoleucine conjugate of JA (JA-Ile), triggers secretion of digestive enzymes without any preceding mechanical stimulus. Such secretion is accompanied by slow trap closure. Under physiological conditions, insect-capture is associated with Ca(2+) signaling and a rise in OPDA, Apparently, jasmonates bypass hapto-electric processes associated with trap closure. However, ABA does not affect OPDA-dependent gland activity. Therefore, signals for trap movement and secretion seem to involve separate pathways. Jasmonates are systemically active because application to a single trap induces secretion and slow closure not only in the given trap but also in all others. Furthermore, formerly touch-insensitive trap sectors are converted into mechanosensitive ones. These findings demonstrate that prey-catching Dionaea combines plant-specific signaling pathways, involving OPDA and ABA with a rapidly acting trigger, which uses ion channels, action potentials, and Ca(2+) signals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / pharmacology
  • Action Potentials / drug effects
  • Amino Acids / pharmacology
  • Animals
  • Cyclopentanes / pharmacology
  • Droseraceae / anatomy & histology*
  • Droseraceae / drug effects
  • Droseraceae / physiology*
  • Fatty Acids, Unsaturated / biosynthesis
  • Indenes / pharmacology
  • Insecta / drug effects
  • Insecta / physiology
  • Oxylipins / pharmacology
  • Plant Growth Regulators / pharmacology*
  • Plant Leaves / drug effects
  • Plant Leaves / physiology
  • Predatory Behavior / drug effects
  • Stress, Mechanical
  • Time Factors

Substances

  • Amino Acids
  • Cyclopentanes
  • Fatty Acids, Unsaturated
  • Indenes
  • Oxylipins
  • Plant Growth Regulators
  • coronatine
  • 12-oxophytodienoic acid
  • jasmonic acid
  • Abscisic Acid