Table II.

Amounts and activities of Rubisco in tobacco WT and the CMSII mutant

MeasurementWTCMSII
Total catalytic sites
 Dark42 ± 256 ± 4
 Light42 ± 256 ± 2
Initial activity
 Dark33 ± 229 ± 2
 Light134 ± 5135 ± 4
Total activity
 Dark69 ± 677 ± 4
 Light130 ± 3132 ± 3
Maximal activity
 Dark125 ± 3125 ± 3
 Light121 ± 2122 ± 4

Samples were taken from plants dark adapted for 5 h (dark) or illuminated at an irradiance of 700 μmol m−2s−1 for 2 h (light). Initial, total, and maximal activities are expressed as μmol CO2 min−1μmol−1 Rubisco. Total Rubisco catalytic sites are expressed as nmol Rubisco mg−1 chlorophyll. For details, see “Materials and Methods.” Data are means ± seof samples from four different plants.