Effects of nutrient deprivation on photosynthetic pigments and ultrastructure of chloroplasts in Porphyra yezoensis

Abstract

To understand the "chlorosis" in the thalli of Porphyra yezoensis, we examined the reduction of photosynthetic pigments and the changes in ultrastructures of cells and organelles. In two-week culture in the media without N, P or Fe, all thalli gradually discolored. Photosynthetic pigments (chlorophyll a, phycoerythrin and phycocyanin) extensively reduced, though the degree and the pattern of the reduction varied according to deprived nutrients. While the chloroplasts shrank due to the nutrient deprivation, the vacuoles swelled and the starch grains accumulated in cytoplasm.