Regulation of seed dormancy by ETR1/RDO3 (Plant Cell)

Seed dormancy is an essential fitness trait for plants as it allows their seeds to survive adverse seasons and to synchronise their germination with the occurrence of suitable conditions. While the molecular pathways of the major phytohormones involved in seed dormancy have been largely elucidated, the mechanisms of others remain elusive. In the case of ethylene the underlying molecular mechanism is not well understood although this phytohormone has been shown to play a pivotal role in  the control of seed dormancy and germination. Here, Li et al. report the identification of the Arabidopsis reduced dormancy 3 (rdo3) mutant and show that RDO3 encodes the ethylene receptor ETR1. Furthermore, they demonstrate that ERF12 plays a key role in the regulation of seed dormancy by interacting with the transcriptional co-repressor TOPLESS (TPL) in the downstream pathway of ethylene signaling mediated by ETR1/RDO3. Moreover, major dormancy factor DELAY OF GERMINATION1 (DOG1) is a direct target of the ERF12-85-TPL repressor complex, underlining the role of ethylene signaling in the regulation of seed dormancy. (Summary by Florian Ahloumessou) Plant Cell 10.1105/tpc.18.00449