RALF33-FERONIA signaling orchestrates postwounding root-tip regeneration via TPR4-ERF115 dynamics

Area of Science:

• Plant biology
• Molecular mechanisms
• Regenerative biology

Background:

• The molecular basis of plant tissue and organ regeneration after wounding remains largely unknown.
• Understanding these mechanisms is crucial for advancing plant science and agriculture.

Purpose of the Study:

• To identify and elucidate the signaling pathway regulating wound-induced root regeneration in Arabidopsis thaliana.
• To highlight the roles of specific peptides and receptors in this process.

Main Methods:

• Investigated the function of RAPID ALKALINIZATION FACTOR33 (RALF33) and its receptor FERONIA (FER) in Arabidopsis root regeneration.
• Analyzed the interaction between RALF33, FER, TOPLESS-RELATED4 (TPR4), and ETHYLENE RESPONSE FACTOR115 (ERF115) using genetic and molecular approaches.
• Utilized alanine substitutions to study the impact of phosphorylation site disruption on TPR4 function.

Main Results:

• Wounding induces RALF33 accumulation, which promotes root regeneration.
• Mutants lacking functional FER (fer mutants) show enhanced regeneration.
• RALF33 hinders FER-mediated phosphorylation of TPR4, preventing its nuclear localization and interaction with ERF115.
• ERF115 exhibits increased transcriptional activity when not bound by TPR4.
• Mutating TPR4 phosphorylation sites (TPR4A) causes mislocalization and impaired ERF115 binding.

Conclusions:

• The RALF33-FER-TPR4-ERF115 signaling cascade is a key regulator of wound-induced root regeneration in plants.
• This pathway provides critical insights into the intricate control of plant regenerative responses.
• Findings offer a foundation for future research into enhancing plant regeneration capabilities.