Fig. 6.

Effects of anoxic conditions on SuSy activity in soluble and membrane fractions extracted from pondweed turions. SuSy was extracted from pondweed turions incubated at 25 °C in the dark in air (open bars) and under anoxia (shaded bars) for 3 d. Total activity of SuSy was determined in the supernatant after centrifugation of the extract at 7000 g for 20 min. The activity of soluble SuSy and membrane-bound SuSy was determined in the soluble fraction and in the microsomal fraction separated by ultracentrifugation at 95 000 g for 1 h. SuSy activity was measured by the method described in Materials and Methods. Data are means ± s.e. of three separate replicates. Significantly different from the activity in air at: ^*P < 0·1, ^**P < 0·05 (t-test).