Unveiling REF1: A key regulator of plant regeneration

Plants frequently encounter damage during growth and development, necessitating remarkable regenerative abilities to repair damaged tissues. Plants can regenerate organs or even entire plants from callus or a single cell, a capacity underpinning asexual reproduction and various biotechnological applications. While numerous studies have investigated the plant regenerative response triggered by damage, the nature of the damage signal and its perception remain unclear. Tomato, a widely used model, has contributed significantly to the understanding of systemic defense and regeneration. Yang et al. characterized the tomato gene SPR9, which encodes the precursor of SlPep, which is a known elicitor peptide. The mutant spr9 exhibits impaired regenerative ability due to an attenuated damage signal critical for defense and regenerative responses. The study demonstrated that the loss of the SlPep precursor gene or its receptor disrupts wound-induced callus formation and the regenerative capacity, while its overexpression enhances regeneration. Furthermore, exogenous application of SlPep significantly improves regenerative capacity. Therefore, this small peptide has been renamed the regeneration factor REF1. REF1 activates SlWIND1, the main homolog of the tomato cell reprogramming regulator WIND1, which amplifies the REF1 signal by transcriptionally activating the REF1 precursor gene. In conclusion, this study established REF1 as a local wound signal for plant regeneration. This discovery provides a promising target for improving the regenerative capacity and transformation efficiency of recalcitrant crops. (Summary by Yuanyuan Liu @YuanyuanLiu12) Cell 10.1016/j.cell.2024.04.040