Fig. 9 in Tissue specificity of (E)-β-farnesene and germacrene D accumulation in pyrethrum flowers

Fig. 9. Dynamic emission and distribution of the two predominant sesquiterpene volatiles EβF and GD in T. cinerariifolium flower. EβF and GD concentrations peak at the S2 flower stage. Their microdistribution patterns strongly differ though: the peduncle is dominated by EβF but the corolla and stigma by GD. This uneven distribution leads to a dominant EβF emission at the S2 flower stage which attracts ladybird beetles and repels aphids. Presumably the later dominance of GD released from the stigma and corollas when disc florets open up is promoting the pollination process. In peduncle, relatively pure EβF was largely produced in the parenchyma cells and further transported and stored in the secretory ducts. Lines at the S2 and S4 flower stages show the EβF/GD oil ducts. Pyrethrins were increasingly accumulated in the pericarp of the developed ovary.