Arabidopsis enhanced ethylene response 4 encodes an EIN3-interacting TFIID transcription factor required for proper ethylene response, including ERF1 induction.

eer4 was isolated as an Arabidopsis mutant with an extreme response to ethylene in dark-grown seedlings that was also found to have partial ethylene insensitivity at the level of ethylene-dependent gene expression, including ERF1. Subsequent cloning of eer4 revealed an inappropriate stop codon in a previously uncharacterized TFIID-interacting transcription factor homologous to human TAF12 and yeast TAF61. Genetic and pharmacological analysis demonstrated that the eer4 phenotype is strictly ethylene dependent in seedlings, yet a double mutant with the partially ethylene-insensitive Arabidopsis mutant, ein3-1, had restored ethylene responsiveness, indicating that eer4 also regulates a previously unknown resetting or dampening mechanism for the ethylene signalling pathway.