Mutations in the Arabidopsis Lst8 and Raptor genes encoding partners of the TOR complex, or inhibition of TOR activity decrease abscisic acid (ABA) synthesis

Biochem Biophys Res Commun. 2015 Nov 27;467(4):992-7. doi: 10.1016/j.bbrc.2015.10.028. Epub 2015 Oct 14.

Abstract

The Target of Rapamycin (TOR) kinase regulates essential processes in plant growth and development by modulation of metabolism and translation in response to environmental signals. In this study, we show that abscisic acid (ABA) metabolism is also regulated by the TOR kinase. Indeed ABA hormone level strongly decreases in Lst8-1 and Raptor3g mutant lines as well as in wild-type (WT) Arabidopsis plants treated with AZD-8055, a TOR inhibitor. However the growth and germination of these lines are more sensitive to exogenous ABA. The diminished ABA hormone accumulation is correlated with lower transcript levels of ZEP, NCED3 and AAO3 biosynthetic enzymes, and higher transcript amount of the CYP707A2 gene encoding a key-enzyme in abscisic acid catabolism. These results suggest that the TOR signaling pathway is implicated in the regulation of ABA accumulation in Arabidopsis.

Keywords: ABA metabolism; Abscisic acid (ABA); Arabidopsis thaliana; TOR kinase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / biosynthesis*
  • Abscisic Acid / metabolism
  • Arabidopsis / genetics*
  • Arabidopsis Proteins / antagonists & inhibitors
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / physiology
  • Genes, Plant*
  • Mutation*
  • Phosphatidylinositol 3-Kinases
  • Phosphoinositide-3 Kinase Inhibitors
  • Signal Transduction

Substances

  • Arabidopsis Proteins
  • Phosphoinositide-3 Kinase Inhibitors
  • Abscisic Acid
  • TOR protein, Arabidopsis