Figure 3.

Fusicoccin- and expansin-growth responses as a function of initial growth rate. A, Growth response as a function of pretreatment growth rate. The increase in growth rates for cell groups (growth rate after treatment divided by growth rate before treatment) was plotted against the initial (pretreatment) growth rate. The solid and dotted lines represent least-squares fits for the expansin and fusicoccin data, respectively. The line for the expansin data is an exponential decay fit. The dashed line for the fusicoccin data is a first-order fit. B, The growth rate after treatment with expansins is plotted against the pretreatment growth rate. The solid diagonal line (slope = 1) represents where the data would fall if expansin treatment had no effect. The dashed line is a least-squares fit of the data and has a slope of 0.145 ± 0.252, and a y intercept of 2.71%/h. All growth rates were based on change in the optical cross-sectional area versus time.