Fig. 1: Schematic representation of local and systemic wound signaling for regeneration.

a Wounding triggers the release of peptides systemin (yellow) and REF1 (red) in tomato. Systemin triggers systemic wound responses in distant tissues including defense and immune responses. REF1 acts locally in the vicinity of the wound and enhances systemic wound signaling promoting regeneration and wound healing. Rectangular inset represents cells drawn in b. b Cell rupture induces maturation of Pep family member REF1, which is perceived by the receptor PORK1. PORK1 perception of REF1 partly mediates activation of SlWIND1, which drives the expression of REF1 itself. This contributes to the propagation of local wound signaling in cells surrounding the wound site. c Exogenous treatment with REF1 dramatically enhances transformation efficiency in recalcitrant accessions of tomato, soybean, wheat and maize. Removed leaves indicate explant preparation required for crop transformation. Circle with orange arrow indicates a plasmid. Color change indicates successful transformation.