Parameters of photosynthetic and nonphotosynthetic growth in atToc75-III↓ and AtOEP80↓ plants. A, Plants of the indicated genotypes were grown on MS-dexamethasone medium for 10 d. Chlorophyll was determined photometrically. Values shown are means (±se) derived from three independent samples, each one containing 15 plants. Units are nmol chlorophyll a + b per mg fresh weight. B, Plants were grown on MS-dexamethasone agar plates for 10 d. Cotyledon length (from the shoot apex to the tip of the cotyledon) was quantified by analyzing digital images of the plants using SigmaScan Pro software (SPSS Inc.). Values shown are means (±se) derived from 31 to 36 independent measurements per genotype. C, Plants were grown side by side on vertically oriented MS-dexamethasone agar plates for 10 d. Primary root length was quantified by analyzing digital images of 10 independent plates, using SigmaScan Pro, each one carrying approximately 12 plants per genotype. Values shown are the means (±se) from 49 to 64 independent measurements per genotype. D, Plants were grown on MS-dexamethasone medium for 5 d in the dark. They were then laid down horizontally on agar medium for photography, and hypocotyl lengths were quantified by analyzing the digital images as described in the legend to section B. Values shown are means (±se) derived from 49 to 83 independent measurements per genotype.