Table 1.

Relative cyclic electron flow (CEF) and cellular ATP content in wild-type, stt7–9, dum22, and dum22 stt7–9 cells

Strain	CEF	ATP TAP Dark	ATP TAP hν	ATP Min hν
Wild type	0.35 ± 0.05	66.2 ± 6.8	100	93.0 ± 9.1
stt7–9	0.37 ± 0.05	55.9 ± 6.1	102.3 ± 12.3	83.8 ± 20.4
dum22	0.63 ± 0.09	3.0 ± 1.3	69.0 ± 10.0	69.0 ± 10.0
dum22 stt7–9	0.35 ± 0.02	1.8 ± 2.1	65.7 ± 6.5	71.2 ± 2.7

CEF was evaluated as = k * [P₇₀₀⁺]/([P₇₀₀⁺]+[P₇₀₀] after illumination in the presence of DCMU (20 μM), where k represents the P₇₀₀⁺ re-reduction rate after steady-state illumination of saturating intensity. CEF rates at low light (50 μmol m⁻² s⁻¹) are normalized to the maximum value (typically 12.5 ± 0.1 s⁻¹ in wild-type cells). Standard deviation is relative to at least 5 replicates. ATP is expressed in percentage of the wild-type control (107 ± 12 nmol/mg Chlorophyll-1). Cells were fixed after 3 h in the dark or after continuous illumination with low light (50 μmol m⁻²s⁻¹).