. 2008 May 31;59(10):2659–2672. doi: 10.1093/jxb/ern134

Table 2.

Selected parameters of photosynthetic processes in source leaves of wild-type and cytokinin-deficient tobacco plants

Parameter		WT	35S:CKX1	35S:CKX2
abs	(%)	84.0±0.5^a	75.3±0.5^b	80.1±2.9^a
ETR	(μmol e^– m⁻² s⁻¹)	88.2±4.3^a	76.4±6.9^b	83.8±4.7^c
ΦPSII	(rel. units)	0.700±0.034^a	0.676±0.061^a	0.698±0.039^a
J_CO2growth	(μmol CO₂ m⁻² s⁻¹)	9.33±0.90^a	9.53±0.48^a	9.91±0.47^a
J_CO2max	(μmol CO₂ m⁻² s⁻¹)	34.2±14.6^a	38.9±12.1^a	39.1±6.3^a
ΦCO_2app	[mol CO₂ (mol photons)⁻¹]	0.076±0.009^a	0.076±0.003^a	0.076±0.003^a
R_D	(μmol CO₂ m⁻² s⁻¹)	1.75±0.23^a	2.32±0.08^b	2.63±0.42^b

Data represent mean values ±SD (n=33 for ETR; n = 4–5 for other parameters). Values with the same superscript letter in one row do not significantly differ at P < 0.05 (calculated by the Student's t-test). abs, Rate of the absorption of photons in the range of 400–700 nm; ETR, electron transport rate; J_CO2growth, CO₂ uptake rate under growth conditions; J_CO2max, CO₂ uptake rate under light and CO₂ saturation; ΦCO_2app, maximum apparent quantum yield of the CO₂ uptake; ΦPSII, quantum efficiency of PSII; R_D, dark respiration rate; WT, wild type.