Wound-induced small-peptide-mediated signaling cascade, regulated by OsPSKR, dictates balance between growth and defense in rice

Wounding is a general stress in plants that results from various pest and pathogenic infections in addition to environment-induced mechanical damages. Plants have sophisticated molecular mechanisms to recognize and respond to wounding, with those of monocots being distinct from dicots. Here, we show the involvement of two distinct categories of temporally separated, endogenously derived peptides, namely, plant elicitor peptides (PEPs) and phytosulfokine (PSK), mediating wound responses in rice. These peptides trigger a dynamic signal relay in which a receptor kinase involved in PSK perception named OsPSKR plays a major role. Perturbation of OsPSKR expression in rice leads to compromised development and constitutive autoimmune phenotypes. OsPSKR regulates the transitioning of defense to growth signals upon wounding. OsPSKR displays mutual antagonism with the OsPEPR1 receptor involved in PEP perception. Collectively, our work indicates the presence of a stepwise peptide-mediated signal relay that regulates the transition from defense to growth upon wounding in monocots. [Display omitted] •Wounding in rice triggers a signal relay between the small peptides OsPep3 and PSK•OsPSKR receptor perceives PSK and plays a key role in rice growth and development•OsPSKR dictates gene expression and promotes transition of wound responses•OsPSKR counters OsPEPR1-mediated signaling leading to balanced growth and defense Harshith et al. show that rice wound responses involve small-peptide-mediated signal relay between defense signaling PEPs and growth signaling by a PSK peptide hormone. OsPSKR receptor perceives PSK and maintains balance between growth and defense signaling during homeostasis and promotes growth post-wounding.