The study demonstrates that plasmodesmata‑located protein 5 (PDLP5) interacts with plasma membrane intrinsic proteins (PIPs) to inhibit H2O2 transport across the plasma membrane in Arabidopsis. Overexpression of PDLP5 reduces H2O2 uptake and diminishes H2O2‑induced root growth inhibition, whereas pdlp5 mutants show enhanced sensitivity, with PIP2;5 identified as a key target of this regulation.

The study demonstrates that invasion of Arabidopsis thaliana roots by the parasitic plant Phtheirospermum japonicum induces a phosphate‑starvation response in the host, which in turn leads to systemic suppression of immunity. This immunosuppression makes Arabidopsis more vulnerable to secondary microbial infections, highlighting the importance of multitrophic interactions in crop resilience.