EIL1

EIL1, short for Ethylene-Insensitive-Like 1, is a transcription factor in plants that belongs to the EIN3-like family. It is closely related to EIN3 and acts as a central regulator of ethylene signaling by activating transcription of ethylene-responsive genes in the nucleus. EIL1 proteins contain a conserved EIN3-like DNA-binding domain and function together with other transcription factors to coordinate ethylene-mediated developmental and stress responses.

In the canonical ethylene signaling pathway, perception of ethylene leads to stabilization of EIN3 and EIL1 in the nucleus. This stabilization occurs in part through suppression of the F-box proteins EBF1 and EBF2, which target EIN3-family proteins for proteasomal degradation in the absence of ethylene. Once stabilized, EIL1 binds to promoters containing ethylene response elements and promotes transcription of Ethylene Responsive Factors (ERFs) and other ethylene-responsive genes, thereby modulating processes such as seedling triple response, leaf senescence, fruit ripening, and responses to biotic and abiotic stresses. EIL1 activity can be modulated by developmental stage, tissue type, and cross-talk with other hormone signaling pathways, including auxin and jasmonate.

Genetic studies, particularly in Arabidopsis thaliana, show that EIL1 functions with EIN3 and other EIL family members, with overlapping and partly redundant roles in mediating ethylene responses. In crops, homologs of EIL1 contribute to traits influenced by ethylene, such as fruit ripening and stress tolerance, making EIL1 and its relatives potential targets for agricultural trait improvement.