Saposhnikovia divaricata, (Turcz.) Schischk (Turcz.) Schischk

Nishidono, Yuto, Niwa, Kotaro, Kitajima, Aoi, Watanabe, Shiro, Tezuka, Yasuhiro, Arita, Masanori, Takabayashi, Junji & Tanaka, Ken, 2021, α-Linolenic acid in Papilio machaon larvae regurgitant induces a defensive response in Apiaceae, Phytochemistry (112796) 188, pp. 1-7 : 3-4

2.3. The effects of α - LA on the production of defensive specialized metabolites in S. divaricata

Detailed comparative analysis of GC–MS data revealed that the contents of two compounds, (R)-falcarinol and bergapten, were increased in the whole plant after α- LA treatment of the plant ( Fig. 5 ). The peaks were annotated or identified as shown in Table S3. The quantitative results of (R)-falcarinol and bergapten contents are shown in Fig. 6 . There was a significant difference in the extent of the increase in (R)-falcarinol (p <0.05). Similarly, the bergapten content tended to increase, but the difference was not significant.

Berenbaum (1983) reported that coumarin and its derivatives, linear and angular furanocoumarins, are toxic to Lepidopteran insects in the context of coevolution and furanocoumarins, such as bergapten, are more toxic to herbivores than coumarin. These compounds are thought to act as direct defense compounds in plants of the Rutaceae and Apiaceae families. Furthermore, studies have reported the insecticidal (mosquitocidal and nematocidal) activities of (R)-falcarinol, a polyacetylene compound in Apiaceae and Araliaceae plants ( Eckenbach et al., 1999; Liu et al., 2016). In addition, Czyzewska et al. (2014) indicated the potent insecticidal activity of falcarinol associated with γ- aminobutyric acidergic block in herbivorous insects. These results suggest that α- LA, a major component in the regurgitant of P. machaon hippocrates larvae, can induce the biosynthesis of compounds involved in the direct defense of S. divaricata .

Figures

Fig. 5. GC–MS TIC chromatograms of extracts of S. divaricata treated with water (1) or α-LA (2) for 5 days.

Fig. 6. Accumulation of specialized metabolites in S. divaricata treated with α-LA or water for 5 days. Contents in fresh plants are shown. Values are presented as means ± SE with n = 3 plants per group. The differences were analyzed using Student’s t-test. The significance was set at *P <0.05 compared with water treatment (control).