The study demonstrates that knock‑down of CDP‑DAG synthase (CDS) genes in Arabidopsis thaliana enhances resistance to multiple pathogens but incurs a growth penalty, associated with elevated reactive oxygen species and MAPK activation. Integrated lipidomics, transcriptomics, and metabolomics reveal PA accumulation in cds mutants, which triggers JA and SA signaling and increases defense‑related metabolites such as serotonin.