. 2006 Oct;142(2):662–672. doi: 10.1104/pp.106.085167

Table II.

Gas exchange, CA activity, Δ¹⁸O, and isotopic equilibrium measurements

Net CO₂ assimilation rate (A), the pCO₂ at the site of CO₂-H₂O oxygen exchange in the mesophyll cytosol (p_m), the ratio of mesophyll cytosolic to ambient CO₂ partial pressure (p_m/p_a), the residence time of CO₂ in the aqueous phase within the leaf (τ), stomatal conductance (g_s), leaf CA activity (CA_leaf), online Δ¹⁸O discrimination, and proportion of chloroplast CO₂ in isotopic equilibrium with chloroplast water (θ) determined from online Δ¹⁸O measurements (Eq. 7) and predicted from in vitro CA assays and gas exchange (Eq. 9) in F. bidentis and tobacco measured at various irradiances (μmol quanta m⁻² s⁻¹) and the F. bidentis with reduced levels of Rubisco (anti-SSU) and wild-type Z. mays measured at 2,000 (μmol quanta m⁻² s⁻¹). Other conditions are as described in the legend to Figure 1. g_w = 10 mol m⁻² s⁻¹ Pa⁻¹ for all plants except tobacco where g_w = 5 mol m⁻² s⁻¹ Pa⁻¹. n = 3 to 5.

Plant	Irradiance	A				g_s	CA_leaf	Δ¹⁸O	Measured	Predicted
	μmol m⁻² s⁻¹	μmol m⁻² s⁻¹	p_m	p_m/p_a	τ	mol m⁻² s⁻¹	μmol m⁻² s⁻¹	‰	θ	θ
F. bidentis wild type	150	6.2 ± 0.2	410 ± 19	0.77 ± 0.03	11.5 ± 1.6	0.12 ± 0.03	2,855 ± 602	182 ± 38	1.06 ± 0.04	1.00 ± 0.01
	300	12.2 ± 0.2	363 ± 32	0.70 ± 0.06	7 ± 1	0.21 ± 0.07	2,558 ± 652	103 ± 29	0.89 ± 0.02	1.00 ± 0.01
	800	25.9 ± 0.9	283 ± 28	0.59 ± 0.06	3.8 ± 0.4	0.33 ± 0.09	2,000 ± 532	43 ± 10	0.65 ± 0.04	0.99 ± 0.01
	1,400	33.7 ± 1.3	252 ± 25	0.56 ± 0.05	2.8 ± 0.2	0.41 ± 0.07	1,844 ± 262	31 ± 5	0.54 ± 0.04	0.99 ± 0.01
	2,000	37.6 ± 1.2	234 ± 15	0.53 ± 0.03	2.6 ± 0.1	0.42 ± 0.04	1,868 ± 180	23 ± 2	0.45 ± 0.04	0.99 ± 0.01
Tobacco	300	15.9 ± 0.9	161 ± 14	0.45 ± 0.04	5.0 ± 0.3	0.18 ± 0.03	1,197 ± 194	37 ± 4	0.89 ± 0.08	0.99 ± 0.01
	500	21.1 ± 1.5	142 ± 13	0.41 ± 0.04	3.6 ± 0.2	0.25 ± 0.04	1,060 ± 182	29 ± 2	0.81 ± 0.10	0.99 ± 0.01
	800	24.7 ± 1.9	130 ± 11	0.39 ± 0.04	2.9 ± 0.2	0.30 ± 0.06	976 ± 183	23 ± 1	0.67 ± 0.04	0.99 ± 0.01
F. bidentis anti-SSu	2,000	23.6 ± 3.1	323 ± 5	0.68 ± 0.02	4.0 ± 0.7	0.40 ± 0.09	2,285 ± 231	51 ± 3	0.63 ± 0.02	0.99 ± 0.01
Z. mays	2,000	33.9 ± 1.5	86 ± 8	0.19 ± 0.02	1.9 ± 0.1	0.18 ± 0.01	296 ± 32	13 ± 1	0.62 ± 0.10	0.88 ± 0.03