Table 1. Photosystem absorption cross section and Chl a content per P700 in alb3b mutants compared with wild-type cells.

Photosystem absorption cross section was measured as rate of 533-nm (Fx) or 670-nm (Chl a) photons absorbed by the functional thylakoid membranes. The actinic light intensity was adjusted to I₆₇₀ = 2.1 µmol photons m⁻² s⁻¹ and I₅₃₃ = 12 µmol photons m⁻² s⁻¹. Rates of light absorption and utilization are given in photons per second ± sd. P700 quantification was measured from the light-induced ΔA₇₀₀ with 670-nm (Chl a) actinic illumination.

Photosystem	Parameter	Wild Type	alb3b-14	alb3b-16	alb3b-19	Average alb3b	alb3b/Wild Type
PSI	(Fx) 533 nm	2.61 ± 0.40	1.10 ± 0.08	1.17 ± 0.10	1.09 ± 0.00	1.10 ± 0.06	42%
	(Chl) 670 nm	1.93 ± 0.11	1.43 ± 0.05	1.39 ± 0.15	1.39 ± 0.14	1.40 ± 0.01	72.5%
PSII	(Fx) 533 nm	32.30 ± 0.7	13.92 ± 1.96	8.10 ± 1.16	8.58 ± 0.93	10.17 ± 3.24	35%
	(Chl) 670 nm	12.62 ± 2.69	7.21 ± 0.00	7.08 ± 0.90	6.71 ± 1.36	7.00 ± 0.26	55%
Chl a/P700		663% ± 9%:1	466% ± 11%	414% ± 9%	394% ± 11%	425:1	64%