De novo stolon organogenesis in potato leaf callus elicited by Agrobacterium tumefaciens stimulus

Plant cells can undergo cellular reprogramming, enabling pluripotent callus formation from excised leaves. Despite this pluripotency, organs regenerated from leaf callus have predominantly been confined to conventional shoots and roots, leaving the potential to regenerate other specialized organs unknown. In this study, we identified that stolons can be regenerated from potato leaf callus. Furthermore, we demonstrate that Agrobacterium tumefaciens stimulation efficiently induces stolon regeneration and subsequent tuber development from potato leaf callus. The induction of stolon regeneration is abolished when biological activity is removed from the bacterial cultures, indicating that viable bacterial cells are required for this process. Comparative assays using various strains reveal that the C58 chromosomal background is essential for this enhancement. Integrating transcriptome analysis with transgenic functional validation, we find that phosphatidylethanolamine-binding protein (PEBP) family genes are closely involved in this response. Furthermore, we observe that viruses do not readily spread to regenerated stolons through the callus, which lacks a continuous vascular system to serve as a pathway for virus movement. Our findings demonstrate that bacterial stimulation triggers stolon regeneration from pluripotent leaf callus, offering a potential approach for the production of virus-free storage organs in potato.