Artificial exposure to herbivore‐induced volatile organic compounds reduces herbivory and modulates gene expression in potato plants

1. Climate change accelerates pest development, posing a serious threat to agricultural yields worldwide. While the application of chemical pesticides can control pests, their overuse poses risks to human health and the environment and contributes to the emergence of pesticide-resistant populations. Within this context, the use of volatile organic compounds (VOCs) emerges as a promising tool for sustainable crop pest management.

2. Informed by and building on prior work identifying key candidate herbivore-induced volatiles, we investigated whether exposure to artificial VOC blends mimicking those induced by natural herbivore damage enhances potato (Solanum tuberosum) resistance to herbivory.

3. Plants were paired in cages and each cage was exposed to either VOC blends similar to those produced by undamaged (control) plants or VOC blends emulating those from plants damaged by Spodoptera exigua (induced). After 3 days of exposure, one plant per cage was removed and leaf tissue collected for gene expression analyses, while the remaining plants were subjected to an herbivory bioassay to assess resistance to S. exigua feeding. After assessing resistance, we again collected leaves for gene expression analyses in induced receivers.

4. Plants exposed to induced VOC blends exhibited a significant reduction in herbivory compared to those exposed to control blends. Molecular analyses indicated that 4CL defensive gene expression increased to a greater extent in response to damage for plants previously exposed to the induced VOCs blend versus those exposed to control VOC blends, consistent with volatile-mediated priming of induced defences.

5. Synthesis and applications. These findings provide strong mechanistic evidence for VOCs mediating pest resistance and suggest that exposure to herbivore-induced, plant-derived VOCs can enhance pest resistance in potato crops. These results might offer novel information for developing ecologically sustainable plant volatile-based strategies for boosting protection against pests in potato plantations.