Chemical genetics reveals negative regulation of abscisic acid signaling by a plant immune response pathway

Curr Biol. 2011 Jun 7;21(11):990-7. doi: 10.1016/j.cub.2011.04.045. Epub 2011 May 27.

Abstract

Coordinated regulation of protection mechanisms against environmental abiotic stress and pathogen attack is essential for plant adaptation and survival. Initial abiotic stress can interfere with disease-resistance signaling [1-6]. Conversely, initial plant immune signaling may interrupt subsequent abscisic acid (ABA) signal transduction [7, 8]. However, the processes involved in this crosstalk between these signaling networks have not been determined. By screening a 9600-compound chemical library, we identified a small molecule [5-(3,4-dichlorophenyl)furan-2-yl]-piperidine-1-ylmethanethione (DFPM) that rapidly downregulates ABA-dependent gene expression and also inhibits ABA-induced stomatal closure. Transcriptome analyses show that DFPM also stimulates expression of plant defense-related genes. Major early regulators of pathogen-resistance responses, including EDS1, PAD4, RAR1, and SGT1b, are required for DFPM-and notably also for Pseudomonas-interference with ABA signal transduction, whereas salicylic acid, EDS16, and NPR1 are not necessary. Although DFPM does not interfere with early ABA perception by PYR/RCAR receptors or ABA activation of SnRK2 kinases, it disrupts cytosolic Ca(2+) signaling and downstream anion channel activation in a PAD4-dependent manner. Our findings provide evidence that activation of EDS1/PAD4-dependent plant immune responses rapidly disrupts ABA signal transduction and that this occurs at the level of Ca(2+) signaling, illuminating how the initial biotic stress pathway interferes with ABA signaling.

Publication types

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

MeSH terms

  • Abscisic Acid / metabolism
  • Abscisic Acid / pharmacology
  • Abscisic Acid / physiology*
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant / drug effects
  • Osmotic Pressure
  • Piperidines / chemistry
  • Piperidines / pharmacology
  • Plant Proteins / genetics
  • Plant Stomata / drug effects
  • Plants / genetics*
  • Plants / immunology
  • Plants / metabolism
  • Plants / microbiology
  • Pseudomonas syringae / immunology
  • Signal Transduction*
  • Small Molecule Libraries
  • Stress, Physiological
  • Thiones / chemistry
  • Thiones / pharmacology

Substances

  • (5-(3,4-dichlorophenyl)furan-2-yl)piperidine-1-ylmethanethione
  • Piperidines
  • Plant Proteins
  • Small Molecule Libraries
  • Thiones
  • Abscisic Acid