Fig. 1

Undiluted benzaldehyde (ccBA) and diacetyl (ccDA) induce food aversion and toxicity. a Representative images of food leaving behavior in response to a 50-min exposure to various concentrations of BA. BA was placed in an ethanol vehicle in a total volume of 1 μl in the middle of the bacterial lawn. b Dose dependence of food avoidance after a 30-min exposure to BA or a 50-min exposure to DA. BA or DA was placed in a total volume of 1 μl or 4 μl in the middle of the bacterial lawn. c Time dependence of 1 μl ccBA-induced food avoidance. d Time dependence of 4 μl ccDA-induced food avoidance. e Time dependence curves of paralysis to various doses of ccBA. f Time dependence curves of paralysis to various doses of ccDA. g Exposure time dependence of survival to the highest, 8 μl dose of ccBA. h Exposure time dependence of survival to the highest, 16 μl dose of ccDA. Survival was scored 14 h after the end of exposures. i Representative stereomicroscopic images of worms 14 h after a 3-h exposure to 8 μl ccBA or 16 μl ccDA. The mean durations of odor exposure that induced 50% paralysis by log rank (Mantel-Cox) test were as follows: ccBA - 2 μl 5.27 h ± 0.17 h, 4 μl 2.94 ± 0.21 h, and 8 μl 0.94 ± 0.14 h; ccDA - 8 μl 5.68 ± 0.20 h and 16 μl 3.46 ± 0.17 h. Compared to 1 μl BA or 4 μl DA treatments p < 0.001 in all conditions. Data are expressed as mean ± SEM. N, number of independent experiments. p values were obtained by one-way ANOVA with Fisher’s LSD post hoc test. n.s., not significant; *p < 0.05; **p < 0.01; ***p < 0.001