Function
The MKK9-MPK3/MPK6 module functions by phosphorylating and activating EIN3, which in turn promotes EIN3-mediated transcription in the ethylene signaling pathway. MKK9 exhibits autophosphorylation activity and also phosphorylates MPK3 and MPK6. This kinase plays a critical role in ethylene and camalexin biosynthesis, as well as in the plant's response to salt stress. The MKK9-MPK6 module is a positive regulator of leaf senescence.