Systemic acquired resistance (SAR)-associated molecules induce resistance in lab- and greenhouse-grown cucumber

The ability of SAR-associated molecules to induce resistance in cucumbers to Pseudomonas syringae pv lachrymans (lab-grown) and powdery mildew (greenhouse-grown), was investigated. Single treatments with glycerol, azelaic acid or pipecolic acid elicited modest levels of resistance in lab experiments, while single treatments with Actigard elicited high levels of resistance in both lab and greenhouse experiments. Multiple treatments with pipecolic acid elicited modest to high levels of resistance in lab-grown plants, but not in greenhouse-grown cucumber. SAR marker gene expression was observed in pipecolic acid-treated lab-grown cucumber plants. This knowledge may inform methods to protect greenhouse crops against disease.