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

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 <i>BGLU</i> genes in <i>Carya illinoinensis</i> (pecan) and demonstrated that <i>CiBGLU21</i>, a β-glucosidase-encoding gene, plays an important positive role in graft healing. The overexpression of <i>CiBGLU21</i> 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 <i>CiBGLU21.</i> The current investigation revealed a CiWOX13/14<i>-CiBGLU21</i> 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.