Plants cannot move away from harm, yet they possess remarkable regenerative abilities that allow them to recover from injury such as herbivore damage, or environmental stress. It is known that plants can repair the damaged vascular tissue such as tree bark girdling through regeneration. But because most regeneration studies have focused on trees, the view of how this repair happens has remained limited, offering only tissue-level resolution.
The new study, led by Professor Ari Pekka Mähönen, provides unprecedented insight into how cambium stem cells are regenerated and regulated during development and repair. Using Arabidopsis thaliana as a model, the researchers selectively eliminated specific cell types in vascular tissues, allowing them to observe regeneration at single-cell resolution. Their findings reveal that xylem cells and cambium stem cells together form a stem-cell niche, an interchangeable unit — when one cell type is damaged, the other can take over and rebuild it. This regeneration is associated with the polar transport of the plant hormone auxin.
In addition, the study also found that in the primary vascular tissue, primary xylem cells with auxin maximum defines where the cambium stem cells form. “When I disrupted auxin transport or destroyed primary xylem cells, the normally well-organized cambium structure broke down, and stem cells reappeared in scattered positions throughout the root vascular tissues” explains Dr. Xixi Zhang, co-first author of the study.
Taken together, the study highlights that undifferentiated xylem cells function as a reservoir for rebuilding cambium stem cells, while auxin transport ensures that the regeneration occurs. These insights deepen our understanding of how plants maintain and repair one of their most critical tissues and may ultimately inform forestry, crop science, and plant biotechnology.