Figure 5.

Exponential decline time courses of total g_s (a) and A (b) in illuminated mature pea leaves after exposure at t = 0 to 0.63 W m⁻² of UV-B irradiation. Lines shown were fitted by nonlinear regression using the model y = y_f + ae^−b(t−to), where y_f is the estimated final value, b is (time constant)⁻¹, t_o is the lag time, and a the overall change in y. Symbols indicate means of three leaves replotted from Figure 4.