A circadian rheostat drives proton electrochemical gradients to optimize cell-type-specific growth in Arabidopsis - PubMed
3 days ago
- #circadian clock
- #electrochemical signals
- #Arabidopsis growth
- Plant growth is regulated by transcription factors and electrochemical signals.
- Apoplastic pH in epidermal cells oscillates opposite to phloem pH, influenced by the clock component CCA1.
- CCA1 lowers apoplastic pH in hypocotyl epidermal cells but increases it in companion cells, affecting growth.
- This regulation promotes hypocotyl growth while inhibiting root elongation.
- CCA1 activates auxin signaling in shoots and represses sucrose transporter 2 and H+-pump ATPase AHA3.
- Repression of AHA3 decreases sucrose loading into the phloem and slows transport velocity.
- Overexpression of AHA3 in CCA1 overexpressing seedlings rescues root growth.
- A circadian rheostat optimizes source capacity with sink demand through electrochemical signals.