Figure 3.

Thellier plots of initial uptake velocities (curve A) and of steady state uptake rates in adapted states (curve B) vs the logarithm of the respective concentrations; Graph A obtained from the initial velocities of Figure 2 was fitted using the non linear equation: J_P= 1.0 · (log[P_e] − log(0.74 · 10⁻⁹)) + (3.0 · (log[P_e] − log(0.74 · 10⁻⁹))³, whereas graph B obtained from the steady state rates of Figure 2 was fitted using the linear function J_P = 12.3 · (log[P_e] − log(9.38 · 10⁻⁹)). The phosphate uptake rate J_P is given as µmol · (mg chl.·h)⁻¹, the logarithm of the external phosphate concentration is expressed relative to the unit standard concentration.