CrADT ‐mediated lignin deposition promotes cut segments of Cyperus rotundus mature tubers self‐healing, contributing to its spread under mechanized tillage

Abstract BACKGROUND Cyperus rotundus L. (purple nutsedge) is a troublesome weed in sugarcane fields due to its prolific underground tuber network. While deep tillage removes its above‐ground biomass, our previous study revealed that each fragmented mature tuber could survive and regenerate more effectively than intact ones, suggesting a strong self‐healing capacity. This study aims to uncover the physiological and molecular mechanisms enabling self‐healing and survival of fragmented C. rotundus tubers under field‐simulated mechanical treatments. RESULTS The results showed that mechanical damage significantly upregulated the expression of CrADT4 , CrADT5 , and CrADT6 , leading to rapid lignin layer formation at the wound surface of damaged mature tubers (DMT), and typical sugarcane tillage temperatures (28 °C–40 °C) could accelerate the ADT ‐mediated lignification process to promote wound healing and fragment survival. Furthermore, Carboxy‐PTIO [2‐(4‐carboxyphenyl)‐4,4,5,5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide] treatment of DMT could suppress lignin deposition and significantly inhibited CrADT5 expression at 3 and 5 days after wounding. Additional heterologous expression revealed that CrADT5‐OE and CrADT6‐OE transgenic lines enhanced lignin accumulation and promoted growth compared with wild‐type (WT) plants, demonstrating that CrADT5 and CrADT6 contribute to lignin synthesis. CONCLUSION These results highlight the important roles of CrADT ‐mediated lignification in DMT wound healing. By elucidating this self‐healing mechanism, this study offers insights into the dominance of C. rotundus in sugarcane fields and potential control strategies. © 2025 Society of Chemical Industry.