Transcriptional and post-transcriptional regulation of a NAC1 transcription factor in Medicago truncatula roots
Article first published online: 19 APR 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 191, Issue 3, pages 647–661, August 2011
How to Cite
D’haeseleer, K., Den Herder, G., Laffont, C., Plet, J., Mortier, V., Lelandais-Brière, C., De Bodt, S., De Keyser, A., Crespi, M., Holsters, M., Frugier, F. and Goormachtig, S. (2011), Transcriptional and post-transcriptional regulation of a NAC1 transcription factor in Medicago truncatula roots. New Phytologist, 191: 647–661. doi: 10.1111/j.1469-8137.2011.03719.x
- Issue published online: 20 JUL 2011
- Article first published online: 19 APR 2011
- Received: 17 December 2010, Accepted: 6 March 2011
- lateral root;
- •Legume roots develop two types of lateral organs, lateral roots and nodules. Nodules develop as a result of a symbiotic interaction with rhizobia and provide a niche for the bacteria to fix atmospheric nitrogen for the plant.
- •The Arabidopsis NAC1 transcription factor is involved in lateral root formation, and is regulated post-transcriptionally by miRNA164 and by SINAT5-dependent ubiquitination. We analyzed in Medicago truncatula the role of the closest NAC1 homolog in lateral root formation and in nodulation.
- •MtNAC1 shows a different expression pattern in response to auxin than its Arabidopsis homolog and no changes in lateral root number or nodulation were observed in plants affected in MtNAC1 expression. In addition, no interaction was found with SINA E3 ligases, suggesting that post-translational regulation of MtNAC1 does not occur in M. truncatula. Similar to what was found in Arabidopsis, a conserved miR164 target site was retrieved in MtNAC1, which reduced protein accumulation of a GFP-miR164 sensor. Furthermore, miR164 and MtNAC1 show an overlapping expression pattern in symbiotic nodules, and overexpression of this miRNA led to a reduction in nodule number.
- •This work suggests that regulatory pathways controlling a conserved transcription factor are complex and divergent between M. truncatula and Arabidopsis.