VOC-mediated within-plant communications and nonvolatile systemic signals upregulate pyrethrin biosynthesis in wounded seedlings of Chrysanthemum cinerariaefolium

摘要

Abstract Natural pyrethrins biosynthesized by Chrysanthemum cinerariaefolium exhibit insecticidal activity, thereby acting as a defense system against herbivores. Here, we study the effects of mechanical wounding and wound-induced volatile organic compounds (VOCs) on pyrethrin biosynthesis in the seedlings of C. cinerariaefolium. Mechanical wounding resulted in enhanced content of pyrethrins I and II in the seedlings. Wrapping the intact leaves of the wounded seedlings prevented the increase in pyrethrin I but not in pyrethrin II, suggesting that the wound-induced VOCs are involved in the regulation of pyrethrin I biosynthesis, whereas nonvolatile systemic signals play a more important role than the wound-induced VOCs in the regulation of pyrethrin II biosynthesis.