Arabidopsis thaliana CENTRORADIALIS homologue (ATC) acts systemically to inhibit floral initiation in Arabidopsis
Article first published online: 23 JUL 2012
© 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd
The Plant Journal
Volume 72, Issue 2, pages 175–184, October 2012
How to Cite
Huang, N.-C., Jane, W.-N., Chen, J. and Yu, T.-S. (2012), Arabidopsis thaliana CENTRORADIALIS homologue (ATC) acts systemically to inhibit floral initiation in Arabidopsis. The Plant Journal, 72: 175–184. doi: 10.1111/j.1365-313X.2012.05076.x
- Issue published online: 16 OCT 2012
- Article first published online: 23 JUL 2012
- Accepted manuscript online: 15 JUN 2012 11:49AM EST
- Received 15 February 2012; revised 21 May 2012; accepted 11 June 2012; published online 23 July 2012.
- RNA movement;
- Arabidopsis thaliana;
- cleft grafting
Floral initiation is orchestrated by systemic floral activators and inhibitors. This remote-control system may integrate environmental cues to modulate floral initiation. Recently, FLOWERING LOCUS T (FT) was found to be a florigen. However, the identity of systemic floral inhibitor or anti-florigen remains to be elucidated. Here we show that Arabidopsis thaliana CENTRORADIALIS homologue (ATC), an Arabidopsis FT homologue, may act in a non-cell autonomous manner to inhibit floral initiation. Analysis of the ATC null mutant revealed that ATC is a short-day-induced floral inhibitor. Cell type-specific expression showed that companion cells and apex that express ATC are sufficient to inhibit floral initiation. Histochemical analysis showed that the promoter activity of ATC was mainly found in vasculature but under the detection limit in apex, a finding that suggests that ATC may move from the vasculature to the apex to influence flowering. Consistent with this notion, Arabidopsis seedling grafting experiments demonstrated that ATC moved over a long distance and that floral inhibition by ATC is graft transmissible. ATC probably antagonizes FT activity, because both ATC and FT interact with FD and affect the same downstream meristem identity genes APETALA1, in an opposite manner. Thus, photoperiodic variations may trigger functionally opposite FT homologues to systemically influence floral initiation.