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

S�nchez-Montesino, Roc�o; Bouza-Morcillo, Laura; Marquez, Julietta; Ghita, Melania; Duran-Nebreda, Salva; G�mez, Luis; Holdsworth, Michael J; Bassel, George; O�ate-S�nchez, Luis

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 regulatory effectors of EXPA2 expression, GA-mediated endosperm expansion and seed germination. The DELLA protein RGL2 repressed activation of EXPA2 promoter by NAC. Our findings demonstrate a key role of this gene network in regulating endosperm cell-expansion to control the seed to seedling transition.

Citation

Sánchez-Montesino, R., Bouza-Morcillo, L., Marquez, J., Ghita, M., Duran-Nebreda, S., Gómez, L., Holdsworth, M. J., Bassel, G., & Oñate-Sánchez, L. (2019). A regulatory module controlling GA-mediated endosperm cell expansion is critical for seed germination in Arabidopsis. Molecular Plant, 12(1), 71-85. https://doi.org/10.1016/j.molp.2018.10.009

• Journal Article Type: Article
• Acceptance Date: Oct 31, 2018
• Online Publication Date: Nov 10, 2018
• Publication Date: Jan 7, 2019
• Deposit Date: Nov 6, 2018
• Publicly Available Date: Nov 11, 2019
• Journal: Molecular Plant
• Print ISSN: 1674-2052
• Electronic ISSN: 1752-9867
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 1
• Pages: 71-85
• DOI: https://doi.org/10.1016/j.molp.2018.10.009
• Keywords: cell expansion; cell-wall remodeling enzymes; endosperm; expansin; NAC transcription factors; seed germination
• Public URL: https://nottingham-repository.worktribe.com/output/1232252
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1674205218303356?via%3Dihub