From developmental signalling to reproductive resilience: Expanding the functional landscape of RGF peptides

MAINTEXTClimate change is increasingly exposing crop reproduction to transient yet severe environmental fluctuations.Among these challenges, episodic chilling events during pollen development can dramatically compromise fertility and yield.1,2 In this issue, Chen et al. report a chilling-induced ROOT GROWTH FACTOR (RGF) signaling pathway that safeguards tapetal degeneration, pollen viability, and crop productivity under cold stress.3 By uncovering an unexpected role for RGF peptides in reproductive stress adaptation, this study substantially expands the functional repertoire of peptide signaling beyond its established developmental functions.More broadly, the work suggests that peptide-mediated signaling may contribute to maintaining developmental robustness under environmental perturbation.Here, we discuss how the tomato SlRGF-SlRGFR6-Ca 2+ module may function as a developmental buffering system that stabilizes reproductive developmental trajectories during transient cold episodes.This concept resonates with Waddington's classical framework of developmental canalization, whereby biological systems maintain stable developmental outcomes despite environmental variation.We further propose that this pathway may represent part of a broader environmental peptide signaling network that translates external cues into adaptive developmental responses.Finally, we suggest that genes such as RGF signaling components exemplify a class of "conditional resilience genes", whose importance becomes evident only under specific environmental challenges.As climate instability increasingly threatens agricultural productivity, engineering reproductive resilience rather than simply enhancing stress tolerance may emerge as a central objective of future crop improvement (Figure 1).