Table I.
Extract | Time | Total Activity | Percentage of 3 pm Control |
---|---|---|---|
μmol CO2 m−2 s−1 | |||
Control | 9 am | 20.9 ± 0.23 | 75 |
3 pm | 27.2 ± 0.25 | 100 | |
200 mm Malate | 3 pm | 27.8 ± 0.28 | 102 |
Control mix | 9 am + 3 pm | 23.5 ± 0.29 | 86 |
Rubisco total activities were measured for morning (9 am) and afternoon (3 pm) control extracts, or after spiking afternoon samples with 200 mm malate or in a mixture comprising 50% morning and 50% afternoon extract. The data are expressed as the means ± se of total Rubisco activity following an 8-min incubation (n = 5) and as mean percentages of the maximum total activity. Desalting morning and afternoon extracts had no discernible effect on either initial or total activities (data not shown).