Coordinately regulated transcription factors EIN3/EIL1 and MYCs in ethylene and jasmonate signaling interact with the same domain of MED25

Ethylene (ET) and jasmonate (JA) are plant hormones that act synergistically to regulate plant development and defense against necrotrophic fungi infections, and antagonistically in response to wounds and apical hook formation. Previous studies revealed that the coordination of these responses is due to dynamic protein-protein interactions (PPI) between their master transcription factors (TFs) EIN3/EIL1 and MYC in ET and JA signaling, respectively. In addition, both TFs are activated via interactions with the same transcriptional mediator MED25, which upregulates downstream gene expression. Herein, we analyzed the PPI between EIN3/EIL1 and MED25, and as with the PPI between MYC3 and MED25, found that the short binding domain of MED25 (CMIDM) is also responsible for the interaction with EIN3/EIL1 - a finding which suggests that both TFs compete for binding with MED25. These results further inform our understanding of the coordination between the ET and JA regulatory systems.

Automated summary

Ethylene and jasmonate are plant hormones that regulate plant development and defense mechanisms. They act synergistically against fungal infections, but antagonistically in response to wounds and apical hook formation. The coordination of these responses is mediated by protein-protein interactions between EIN3/EIL1 and MYC transcription factors. These factors are both activated by interactions with MED25, which upregulates downstream gene expression. The study found that MED25's short binding domain is responsible for the interaction with EIN3/EIL1, suggesting competition between the two transcription factors for binding with MED25. This finding deepens our understanding of the coordination between the ethylene and jasmonate regulatory systems.