Pathogen-herbivore interactions mediated by activated resistance in cucumber

Research with Cucumis sativus has shown that restricted (non-systemic) infection of a cotyledon or the first true leaf with certain fungi or viruses will induce persistent, systemic resistance to later challenges by a wide range of fungal, viral, and bacterial pathogens. The authors tested the hypothesis that restricted inoculation of cucumber with the anthracnose fungus Colletotrichum lagenarium or with tobacco necrosis virus would induce partial, systemic resistance to three generalist herbivores: two-spotted spider mite Tetranychus urticae, fall armyworm Spodoptera frugiperda, and greenhouse whitefly Trialeurodes vaporariorum. They also studied the behavioral response of the cucurbit specialist Diabrotica undecimpunctata to immunized plants. Pathogen-activated induced resistance has little or no effect on plant suitability for herbivores. Similarly, wounding failed to induce systemic resistance to pathogens. -from Authors