The histone acetyltransferase GCN5 and the transcriptional coactivator ADA2b affect leaf development and trichome morphogenesis in Arabidopsis

Jenna Kotak, Marina Saisana, Vasilis Gegas, Nikoletta Pechlivani, Anthanasios Kaldis, Panagiotis Papoutsoglou, Athanasios Makris, Julia Burns, Ashley L. Kendig, Minna Sheikh, Cyrus E. Kuschner, Gabrielle Whitney, Hanna Caiola, John Doonan, Konstantinos Vlachonasios, Elizabeth R. McCain, Amy T. Hark

Research output: Contribution to journalArticlepeer-review

21 Citations (SciVal)
379 Downloads (Pure)


The histone acetyltransferase GCN5 and associated transcriptional coactivator ADA2b are required to couple endoreduplication and trichome branching. Mutation of ADA2b also disrupts the relationship between ploidy and leaf cell size. Dynamic chromatin structure has been established as a general mechanism by which gene function is temporally and spatially regulated, but specific chromatin modifier function is less well understood. To address this question, we have investigated the role of the histone acetyltransferase GCN5 and the associated coactivator ADA2b in developmental events in Arabidopsis thaliana. Arabidopsis plants with T-DNA insertions in GCN5 (also known as HAG1) or ADA2b (also known as PROPORZ1) display pleiotropic phenotypes including dwarfism and floral defects affecting fertility. We undertook a detailed characterization of gcn5 and ada2b phenotypic effects in rosette leaves and trichomes to establish a role for epigenetic control in these developmental processes. ADA2b and GCN5 play specific roles in leaf tissue, affecting cell growth and division in rosette leaves often in complex and even opposite directions. Leaves of gcn5 plants display overall reduced ploidy levels, while ada2b-1 leaves show increased ploidy. Endoreduplication leading to increased ploidy is also known to contribute to normal trichome morphogenesis. We demonstrate that gcn5 and ada2b mutants display alterations in the number and patterning of trichome branches, with ada2b-1 and gcn5-1 trichomes being significantly less branched, while gcn5-6 trichomes show increased branching. Elongation of the trichome stalk and branches also vary in different mutant backgrounds, with stalk length having an inverse relationship with branch number. Taken together, our data indicate that, in Arabidopsis, leaves and trichomes ADA2b and GCN5 are required to couple nuclear content with cell growth and morphogenesis.

Original languageEnglish
Pages (from-to)613-628
Number of pages16
Issue number3
Early online date30 May 2018
Publication statusPublished - 01 Sept 2018


  • endoreduplication
  • epigenetics
  • chromatin
  • histone acetyltransferase
  • Endoreduplication
  • Chromatin
  • Epigenetics
  • Histone acetyltransferase
  • Trichomes/growth & development
  • Histone Acetyltransferases/metabolism
  • Gene Expression Profiling
  • Microscopy, Interference
  • Plant Leaves/growth & development
  • Flow Cytometry
  • Transcription Factors/metabolism
  • Gene Expression Regulation, Developmental
  • Ploidies
  • Gene Expression Regulation, Plant
  • Polymerase Chain Reaction
  • Arabidopsis/enzymology
  • Arabidopsis Proteins/metabolism


Dive into the research topics of 'The histone acetyltransferase GCN5 and the transcriptional coactivator ADA2b affect leaf development and trichome morphogenesis in Arabidopsis'. Together they form a unique fingerprint.

Cite this