Identification of TCP13 as an Upstream Regulator of ATHB12 during Leaf Development

Genes (Basel). 2019 Aug 26;10(9):644. doi: 10.3390/genes10090644.

Abstract

Leaves grow by distinct phases controlled by gene regulatory networks including many transcription factors. Arabidopsis thaliana homeobox 12 (ATHB12) promotes leaf growth especially during the cell expansion phase. In this study, we identify TCP13, a member of the TCP transcription factor family, as an upstream inhibitor of ATHB12. Yeast one-hybrid screening using a 1.2-kb upstream region of ATHB12 resulted in the isolation of TCP13 as well as other transcription factors. Transgenic plants constitutively expressing TCP13 displays a significant reduction in leaf cell size especially during the cell expansion period, while repression of TCP13 and its paralogs (TCP5 and TCP17) result in enlarged leaf cells, indicating that TCP13 and its paralogs inhibit leaf development, mainly at the cell expansion phase. Its expression pattern during leaf expansion phase is opposite to ATHB12 expression. Consistently, the expression of ATHB12 and its downstream genes decreases when TCP13 was overexpressed, and increases when the expression of TCP13 and its paralogs is repressed. In chromatin immunoprecipitation assays using TCP13-GFP plants, a fragment of the ATHB12 upstream region that contains the consensus sequence for TCP binding is strongly enriched. Taken together, these findings indicate that TCP13 and its paralogs inhibit leaf growth by repressing ATHB12 expression.

Keywords: ATHB12; TCP13; cell expansion; leaf development; upstream regulator.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Plant
  • Homeodomain Proteins / genetics*
  • Homeodomain Proteins / metabolism
  • Plant Leaves / genetics*
  • Plant Leaves / growth & development
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism

Substances

  • AT3G02150 protein, Arabidopsis
  • Arabidopsis Proteins
  • AtHB12 protein, Arabidopsis
  • DNA-Binding Proteins
  • Homeodomain Proteins
  • Transcription Factors