Time-evolving genetic networks reveal a NAC troika that negatively regulates leaf senescence in Arabidopsis

Proc Natl Acad Sci U S A. 2018 May 22;115(21):E4930-E4939. doi: 10.1073/pnas.1721523115. Epub 2018 May 7.

Abstract

Senescence is controlled by time-evolving networks that describe the temporal transition of interactions among senescence regulators. Here, we present time-evolving networks for NAM/ATAF/CUC (NAC) transcription factors in Arabidopsis during leaf aging. The most evident characteristic of these time-dependent networks was a shift from positive to negative regulation among NACs at a presenescent stage. ANAC017, ANAC082, and ANAC090, referred to as a "NAC troika," govern the positive-to-negative regulatory shift. Knockout of the NAC troika accelerated senescence and the induction of other NACs, whereas overexpression of the NAC troika had the opposite effects. Transcriptome and molecular analyses revealed shared suppression of senescence-promoting processes by the NAC troika, including salicylic acid (SA) and reactive oxygen species (ROS) responses, but with predominant regulation of SA and ROS responses by ANAC090 and ANAC017, respectively. Our time-evolving networks provide a unique regulatory module of presenescent repressors that direct the timely induction of senescence-promoting processes at the presenescent stage of leaf aging.

Keywords: NAC; leaf senescence; presenescent repressors; salicylic acid response; time-evolving network.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / growth & development*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Cellular Senescence*
  • Gene Expression Regulation, Plant
  • Gene Regulatory Networks*
  • Mutation
  • Phenotype
  • Plant Development
  • Plant Leaves / genetics
  • Plant Leaves / growth & development*
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Time Factors
  • Transcriptome

Substances

  • ATAF1 protein, Arabidopsis
  • Arabidopsis Proteins
  • CUC1 protein, Arabidopsis
  • NARS2 protein, Arabidopsis
  • Repressor Proteins