ZmMKK1 phosphorylates ZmCAT2 to regulate H2O2 homeostasis and improve heat stress tolerance in maize - PubMed
3 hours ago
- #ZmMKK1
- #heat stress
- #phosphorylation
- ZmMKK1 is identified as a key regulator of thermotolerance in maize.
- ZmMKK1 knockout mutants show reduced catalase activity, higher H2O2 levels, and heat stress hypersensitivity.
- Overexpression of ZmMKK1 enhances thermotolerance, confirming its role in heat defense.
- ZmMKK1 physically interacts with and phosphorylates catalase ZmCAT2 at Thr352 and Thr421.
- Phosphomimetic ZmCAT2T352,421D variant enhances catalase activity and rescues zmmkk1 mutants' thermosensitive phenotype.
- ZmMKK1-mediated thermotolerance depends on ZmCAT2 phosphorylation, revealing a non-canonical MAPK cascade mechanism.
- The study offers a new strategy for improving crop stress resistance through direct phosphorylation of non-MAPK substrates.