Figure 3.

Rate of respiratory oxygen consumption as a function of the external oxygen concentration from roots of pea (A) and Arabidopsis (B). For the measurements, roots were kept in a hermetically closed vial in which the oxygen concentration was measured through time. Due to the respiratory activity of the tissue, oxygen depleted from the solution. Respiration rates were calculated from the raw data and plotted here against the external oxygen concentration. The graphs show the values of representative experiments that were repeated at least four times.