In the current study, we found that

In the current study, we found that transgenic-plant-volatiles (VOCos), which included (E)-b-ocimene, from PlOS-overexpress- ing plants, primed defense responses to herbivory in eavesdrop- ping bean and maize plants. We examined these responses under two experimental conditions using an ‘‘open-flow chamber’’ and a ‘‘greenhouse without climate control’’. These experiments con- firmed the importance of relying on realistic experimental conditions for plant-plant communication studies. Firstly, in our ‘‘open-flow’’ condition, both induced direct and indirect defenses (reflected by reduced development/reproduction and attraction of predators) were found to be primed by exposure to VOCos. These results were expected because a variety of plant species, including lima bean and maize, exhibit potent responses to VOCs [3,7,9–11]. Moreover, several angiosperm plants have been reported to show enhanced direct and indirect defenses upon VOC-induced priming, following the transcriptional regulation of genes that mediate oxylipin signaling and defense responses [10,11]. Continuous air-pump and open-flow chamber systems would be useful for clarifying the mechanisms of plant-plant interactions via genetic manipulation and biochemical and ecological analyses.