Work

Poltergeist-Like 2 (PLL2)-dependent activation of herbivore defence distinguishes systemin from other immune signalling pathways

Year: 2025

Type: article

Abstract: Systemin, the first signaling peptide identified in plants, mediates induced resistance against insect herbivores in tomato1. Initially, systemin was perceived as a hormone-like, long-distance messenger that triggers systemic defense responses far from the site of insect attack. It was later found to rather act as a phytocytokine, amplifying the local wound response for the production of downstream signals that activate defense gene expression in distant tissues2. Systemin perception and signaling rely on the systemin receptor SYR13. However, the specifics of SYR1-dependent signaling and how systemin signaling differs from other phytocytokine signaling pathways remain largely unknown. Here, we report that systemin activates the poltergeist-like phosphatase PLL2 in a SYR1-dependent manner. PLL2, in turn, regulates early systemin responses at the plasma membrane, including the rapid inhibition of proton pumps through the dephosphorylation of their regulatory C-termini. PLL2 was found to be essential for downstream defense gene induction, ultimately contributing to insect resistance.

Source: Nature Plants

DOI: 10.1038/s41477-025-02040-7