# The CiWOX13-CiWOX14 Complex Regulates CiBGLU21 to Promote Graft Union Formation by Modulating Cell Wall Synthesis in Carya illinoinensis

## TL;DR

This study identifies a gene complex in pecan trees that helps form graft unions by regulating cell wall synthesis and tissue regeneration.

## Contribution

The discovery of the CiWOX13/14-CiBGLU21 module as a key regulator of graft union formation in Carya illinoinensis.

## Key findings

- CiBGLU21 overexpression increases graft survival and tissue regeneration.
- CiWOX13 and CiWOX14 form heterodimers to activate CiBGLU21 transcription.
- The CiWOX13/14-CiBGLU21 module modulates cell wall synthesis during grafting.

## Abstract

Grafting is an important method for pecans, while the molecular mechanisms underlying graft union formation still need in-depth analysis. In the current investigation, we identified 22 BGLU genes in Carya illinoinensis (pecan) and demonstrated that CiBGLU21, a β-glucosidase-encoding gene, plays an important positive role in graft healing. The overexpression of CiBGLU21 enhanced graft survival rates and accelerated tissue regeneration, while biochemical assays confirmed its role in cell wall reinforcement and sugar metabolism. Additionally, we identified that CiWOX13 formed heterodimers with CiWOX14 to directly and synergistically activate the transcription of CiBGLU21. The current investigation revealed a CiWOX13/14-CiBGLU21 module as an important modulator of graft union formation, offering insights into improving grafting efficiency in perennial crops and advancing the understanding of cell wall dynamics during tissue regeneration.