Regulation of Photosynthetic Capacity in Chlamydomonas mundana1
نویسندگان
چکیده
Summnzarv. A regtulatory system has been described in the obligately phototrophic green alga Chl/amnvdomonlas nitnudana. Cells grown in acetate me(lia are uniable to fix carbon dioxide in the light but carry out a photoassimilation of acetate to carbohydrate: cells cultured with carbon dioxide as the sole source of cellular carbon carry out typical green plant photosynthesis. The control appears to take place at the level of the reductive pentose phosphate cycle. The presence of sodiumi acetate in the medium strongly inhibits formation of ribulose-1-.5-diphosphate carboxylase, ribulose-5-phosphate kinase. andl onie of the 2 fructose-1,6-diphosphate aldolase activities of the cell. Ribose-5-phosphate isomerase is present in higher activity in autotrophic cells. Changes in the levels of triose phosphate dehvdrogenase were also noted. The total pigment content of the cell and the photosyinthetic electron transport reactions are not alteredl unLder different conditionis of growth.
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