A regulatory module controlling GA-mediated endosperm cell expansion is critical for seed germination in Arabidopsis

Research output: Contribution to journalArticlepeer-review

Authors

  • Rocío Sánchez-Montesino
  • Laura Bouza-Morcillo
  • Julietta Marquez
  • Melania Ghita
  • Luis Gómez
  • Michael J. Holdsworth
  • Luis Oñate-Sánchez

Colleges, School and Institutes

Abstract

A key component of seed germination is the interplay of mechanical forces governing embryo growth and the surrounding restraining endosperm tissue. Endosperm cell separation is therefore thought to play a critical role in the control of this developmental transition. Here we demonstrate that in Arabidopsis thaliana seeds, endosperm cell expansion is a key component of germination. Endosperm cells expand to accommodate embryo growth prior to germination. We show that this is an actively regulated process supported by spatiotemporal control of the cell expansion gene EXPANSIN 2 (EXPA2). The NAC transcription factors NAC25 and NAC1L were identified as upstream regulators of EXPA2 expression, gibberellin-mediated endosperm expansion, and seed germination. The DELLA protein RGL2 repressed activation of the EXPA2 promoter by NAC25/NAC1L. Taken together, our findings uncover a key role of the GA/DELLA-NAC25/NAC1L-EXPA2 network in regulating endosperm cell expansion to control the seed-to-seedling transition.

Details

Original languageEnglish
Pages (from-to)71-85
Number of pages15
JournalMolecular Plant
Volume12
Issue number1
Early online date10 Nov 2018
Publication statusPublished - 7 Jan 2019

Keywords

  • cell expansion, cell-wall remodeling enzymes, endosperm, expansin, NAC transcription factors, seed germination