Post-transcriptional control of GRF transcription factors by microRNA miR396 and GIF co-activator affects leaf size and longevity

J.M. Debernardi, M.A. Mecchia, L. Vercruyssen, C. Smaczniak, K. Kaufmann, D. Inze, R.E. Rodriguez, J.F. Palatnik

Research output: Contribution to journalArticleAcademicpeer-review

117 Citations (Scopus)

Abstract

The growth-regulating factors (GRFs) are plant-specific transcription factors. They form complexes with GRF-interacting factors (GIFs), a small family of transcriptional co-activators. In Arabidopsis thaliana, seven out of the nine GRFs are controlled by microRNA miR396. Analysis of Arabidopsis plants carrying a GRF3 allele insensitive to miR396 revealed a strong boost in the number of cells in leaves, which was further enhanced synergistically by an additional increase of GIF1 levels. Genetic experiments revealed that GRF3 can still increase cell number in gif1 mutants, albeit to a much lesser extent. Genome-wide transcript profiling indicated that the simultaneous increase of GRF3 and GIF1 levels causes additional effects in gene expression compared to either of the transgenes alone. We observed that GIF1 interacts in vivo with GRF3, as well as with chromatin-remodeling complexes, providing a mechanistic explanation for the synergistic activities of a GRF3-GIF1 complex. Interestingly, we found that, in addition to the leaf size, the GRF system also affects the organ longevity. Genetic and molecular analysis revealed that the functions of GRFs in leaf growth and senescence can be uncoupled, demonstrating that the miR396-GRF-GIF network impinges on different stages of leaf development. Our results integrate the post-transcriptional control of the GRF transcription factors with the progression of leaf development.
Original languageEnglish
Pages (from-to)413-426
JournalThe Plant Journal
Volume79
Issue number3
DOIs
Publication statusPublished - 2014

Keywords

  • chromatin-remodeling complexes
  • tandem affinity purification
  • arabidopsis-thaliana
  • gene-expression
  • organ size
  • cell-division
  • protein complexes
  • shoot development
  • small rnas
  • growth

Fingerprint Dive into the research topics of 'Post-transcriptional control of GRF transcription factors by microRNA miR396 and GIF co-activator affects leaf size and longevity'. Together they form a unique fingerprint.

Cite this