systemic-defense
Systemic defense refers to the plant-wide activation of immune responses triggered by localized infection or wounding, allowing the entire organism to mount resistance against future attacks. This whole-plant signaling phenomenon—mediated by mobile molecules such as salicylic acid, jasmonic acid, and volatile compounds—is critical to understanding how plants survive in pathogen-rich environments without an adaptive immune system. Research into systemic defense mechanisms has broad implications for developing disease-resistant crops and reducing reliance on chemical pesticides.
open_in_new WikipediaPubMed · 2026-05-01
Austrian pine trees mount a sophisticated, whole-tree defense against a deadly fungal pathogen by coordinating multiple plant hormones in a precise sequence. Early abscisic acid signaling triggers the alarm, while sustained jasmonic acid and its mobile form carry the defensive message throughout the tree.
Early abscisic acid (ABA) signaling is the first hormone wave after infection, initiating the systemic defense response in Austrian pine against Diplodia pinea
Sustained jasmonic acid (JA) signaling — confirmed by both hormone measurements and gene expression data — is required for full activation of whole-tree induced resistance
Mobile methyl jasmonate (MeJA) serves as a long-distance defense signal, with its spatiotemporal accumulation pattern matching genes involved in systemic signal propagation and defense
