The study investigated unexpected leaf spot symptoms in Psa3‑resistant kiwifruit (Actinidia) germplasm, finding that Psa3 was detectable by qPCR and metabarcoding despite poor culturing. Metabarcoding revealed distinct bacterial community shifts in lesions versus healthy tissue, and whole‑genome sequencing identified diverse Pseudomonas spp. that, while not individually more pathogenic, could enhance Psa3 growth, suggesting pathogenic consortia on resistant hosts.

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.