Figure 7.

The relative amounts of newly synthesised free sterol species increase under HS. Only two sterol species are newly synthesised in growing tobacco pollen tubes, a sterol with an exact mass of 412,37 Da that is putatively methylenepollinastanol, and cycloeucalenol. Presented are relative abundances of the respective sterol based on the total ion current as measured by GC–MS, pollen tubes were grown under different temperature regimes. n = 5. Error bars represent standard deviation. For statistical analysis, ANOVA was performed (significance level α = 0.05), followed by post hoc Tukey’s analysis. Results are presented as compact letter display of all pair-wise comparisons in increasing order.