An ancient and conserved function for armadillo-related proteins in the control of spore and seed germination by abscisic acid

Research output: Contribution to journalArticlepeer-review


  • Anushree Choudhary
  • Daniel Holloway
  • Eleanor Vesty
  • Kiran Kaur Bansal
  • Susan Bradshaw

Colleges, School and Institutes

External organisations

  • University of Birmingham


• Armadillo-related proteins regulate development throughout eukaryotic kingdoms. In the flowering plant Arabidopsis, Armadillo-related ARABIDILLO proteins promote multicellular root branching. ARABIDILLO homologues exist throughout land plants, including in early-diverging species lacking true roots, suggesting that early-evolving ARABIDILLOs had additional biological roles.
• Here we investigate, using molecular genetics, the conservation and diversification of ARABIDILLO protein function in plants separated by ~450 million years of evolution.
• We demonstrate that ARABIDILLO homologues in the moss Physcomitrella regulate a previously undiscovered inhibitory effect of abscisic acid (ABA) on spore germination. Furthermore, we show that Arabidopsis ARABIDILLOs function similarly during seed germination. Early-diverging ARABIDILLO homologues from both Physcomitrella and the lycophyte Selaginella can substitute for ARABIDILLO function during Arabidopsis root development and seed germination.
• We conclude that (i) ABA was co-opted early in plant evolution to regulate functionally analogous processes in spore- and seed-producing plants and (ii) plant ARABIDILLO germination functions were co-opted early into both gametophyte and sporophyte, with a specific rooting function evolving later in the land plant lineage.


Original languageEnglish
Pages (from-to)940–951
JournalNew Phytologist
Issue number3
Early online date4 Apr 2016
Publication statusPublished - 11 Jul 2016


  • Evolution, germination, spore, seed, Armadillo proteins, Arabidopsis, moss, abscisic acid