Figure 4
Quantitative analysis of effects of bistheonellide A (BA) on cell plate expansion. (A) and (B) Regression analysis of the data for changes in cell plate diameter of control (open circle) and BA-treated (filled circle) cells. Time 0 min represents the initiation of cell plate formation. Values are arithmetic means ± SE from 12 independent experiments. The continuous and broken lines represent the regression curves for cell plate diameter of control and BA-treated cells, respectively, calculated from model equation 1 (A) or 2 (B). In model equation 1, the expansion rate a is constant (A). In model equation 2, the expanding rate a-btnundergoes time-dependent changes (B). When the control data was applied to model equation 2, n became underspecified and was consequently assumed to be invariant at 1.81. (C) Comparison of p-values in chi-square goodness of fit tests. The p-value indicates the probability that an observed difference between the measured and predicted values by model equations 1 or 2 occurred by chance alone. If the p-value is less than the significant level at 0.05, we cannot accept that there are no differences between the measured and predicted values. Note that the data fit model equation 2 (B) much better than model equation 1 (A). (D) Simulation of changes in the effects of BA treatment on expansion rate calculated at 1 min intervals. The values are arithmetic means ± SE from 12 independent calculation results of a-btn. The 12 parameter sets a and b were the same as calculated in (B). Significance was determined using Student's t-test. p-value *< 0.05. **<0.001. (E) Simulation of changes in the estimated contribution of MFs to cell plate expansion. Values are arithmetic means ± SE from 12 independent calculated results of the decrease proportions of the expanding rate. The decreased proportion was calculated as the ratio of the difference between a-btnin a control and a BA-treated cell to the a-btnin a control cell. The values of a-btnwere the same as calculated in (D). Pairing of the control and BA-treated data was performed under the condition that the difference of a in a control and a BA-treated cell was at a minimum value.