A CLE11b-CLE16 Signaling Relay Mediates Root-Shoot-Root Crosstalk for Drought Adaptation in Common Bean.

Area of Science:

• Plant Biology
• Molecular Plant Science
• Plant Physiology

Background:

• Plant roots detect soil drought and signal shoots for coordinated responses.
• Root-to-shoot signaling is established, but shoot-to-root signaling in drought adaptation is poorly understood.

Purpose of the Study:

• To investigate the role and mechanism of shoot-to-root signaling in plant drought adaptation.
• To identify key signaling molecules and pathways involved in this process.

Main Methods:

• Gene expression analysis in common bean under drought stress.
• Identification of signaling peptides (CLEs) and their receptors (BAMs).
• Analysis of peptide translocation and functional validation of signaling components.

Main Results:

• A novel root-shoot-root signaling relay mediated by CLE peptides (PvCLE11b and PvCLE16) was identified.
• Drought induces root-derived PvCLE11b to signal leaves, upregulating leaf PvCLE16 via PvTCP10.
• Leaf-expressed PvCLE16 moves to roots, suppressing primary root growth and promoting lateral roots, while also inducing stomatal closure.

Conclusions:

• A two-step CLE peptide signaling cascade coordinates whole-plant drought responses.
• This pathway involves upward signaling from roots to leaves and subsequent downward signaling to roots.
• The findings reveal a crucial mechanism for enhancing drought resilience in plants.