MKK4 — Arabidopsis thaliana

Summary

AT1G51660 (MKK4) of Arabidopsis thaliana encodes a mitogen-activated protein kinase kinase (MAPKK) with EC 2.7.12.2. The gene is associated with diverse biological processes including flavone and polyamine metabolism, GABA biosynthesis, floral organ abscission, root system development, and gibberellin-mediated signalling. Observed phenotypes link MKK4 to the hypersensitive response, gene silencing, and chloroplast redox stress response. The gene has been connected to traits such as sodium content, water use efficiency, stomatal resistance, anthocyanin content, seed dormancy, and responses to UV-B light, aphids, and jasmonic acid. It is also associated with lateral root formation, stomatal development, dehydration tolerance, and melatonin-mediated immunity. Studies of related genes in other species link the MKK4 family to resistance to biotrophic pathogens and microtubule stability.