Table II.

Carboxylase activities and the change in sensitivity of PEPC to malate inhibition in W22 and bsd2-m1 leaves harvested after 8 h of darkness (D), after 2 h of low light (LL), and after a further 2 h in moderate light (ML)

Plant Material	Carboxylase Activity (LL)		Inhibition by l-Malatec
	Rubiscoa	PEPCb	D	LL	ML
	μmol min−1 mg−1 protein		%
W22	0.37	1.4	70  ± 8.3	49  ± 5.2	45  ± 5.3
bsd2-m1	0	1.6	64  ± 9.1	48  ± 4.9	40  ± 3.7

Percentage inhibition by 0.5 mm l-malate was determined on a minimum of three leaves from two different batches of plants. se values were no more than 15% for the carboxylase activities, and were as indicated for inhibition by l-malate. See the legend to Figure 2 for other details.

^aRuBP-dependent, CO₂/Mg²⁺-activated activity (pH 8.0, 25 mm NaHCO₃, 0.5 mm RuBP). 

^bAssayed at optimal conditions (pH 8.0, 5 mm PEP). 

^cAssayed at pH 7.3 and 2.5 mm PEP, with or without 0.5 mm l-malate.