On the quantitative relationships between chlorophyll b and the chlorophyll a form Ca685 in the light-harvesting pigment-protein complex of chloroplasts

The relative amounts of chlorophyll b (C») and chlorophyll a685 (C„685) are determined for seven plant species. It is found that the amount of the C* C0685 chlorophyll-protein complex is correlated with the relative amounts of both C* and C„685. However, this relationship differs for these chlorophylls. The same relations are studied for a single species, Phaseolus vulgaris, grown under various light intensities. No changes are observed in plants grown at intensities ranging from 15 to 150 W m 2. At 8 W m 2 the amount of the Ci,-C<,685 complex is hardly changed. However, the ratio of the relative amounts of both components is clearly increased. The results are discussed.