부산대학교 도서관

The timing of plant volatile emissions is important for a robust indirect defense response. Green leaf volatiles (GLVs) are emitted by plants upon damage but can be suppressed by herbivore‐associated elicitors, and the abundance and composition of GLVs vary depending on the timing of herbivore attack. We show that the GLV biosynthetic enzyme HYDROPEROXIDE LYASE (HPL) is transcriptionally regulated by the circadian clock in Nicotiana attenuata. In accordance with transcript abundance of NaHPL, GLV aldehyde pools in intact leaves peaked at night and at subjective night under diurnal and continuous light conditions, respectively. Moreover, although the basal abundance of NaHPL transcripts is upregulated by jasmonate (JA) signaling, JA does not regulate the reduction of NaHPL transcript abundance in damaged leaves by simulated herbivore treatment. Unexpectedly, the plant circadian clock was strongly altered when Manduca sexta larvae fed on N. attenuata, and this was also independent of JA signaling. Lastly, the temporal dynamics of NaHPL transcripts and total GLV emissions were strongly altered by M. sexta larval feeding. Our data suggest that the temporal dynamics of emitted GLV blends result from a combination of damage, JA signaling, herbivore‐associated elicitors, and the plant circadian clock. Herbivore‐induced plant volatiles display complex temporal dynamics, which matter for effectively attracting the natural enemies of herbivores. Here, we show that green leaf volatile (GLV) biosynthesis in the wild tobacco Nicotiana attenuata has a circadian rhythm. Interestingly, although the biosynthesis of GLVs is jasmonate‐dependent, herbivore elicitors suppress GLV biosynthesis. Moreover, herbivory strongly alters the diurnal rhythm of circadian clock gene transcript levels: the effect of herbivory differs depending on the elicitors used and treatment time. This study reveals how a plant shapes its temporal dynamics of GLVs emissions by integrating circadian clock signaling with herbivore‐induced responses. [ABSTRACT FROM AUTHOR]