Photoautotrophic Growth and Photosynthesis in Cell Suspension Cultures of Chenopodium rubrum

Abstract

AbstractA method is described for growing cell suspension cultures of Chenopodium rubrum photoautotrophically for prolonged periods of time. By using a two‐tier culture vessel the growth medium with the cells was separated from the CO2 reservoir. Definite CO2 concentrations were established by a K2CO3/KHCO3 buffer. Photoautotrophic growth in C. rubrum cell suspension cultures was correlated with the CO2 level. At 0.5% CO2 the cell cultures contained 68 μg chlorophyll/g fresh weight and showed an increase in fresh weight of about 80% in 18 days. At 1% CO2 an increase in fresh weight of 165% in 18 days was observed. The chlorophyll content rose up to 84 μg/g fresh weight.The photoautotrophic growth was also greatly influenced by the 2,4‐D content of the medium. Cell growth was enhanced by lowering the auxin concentration. Best growth was attained (210% increase in fresh weight) at 10−8M 2,4‐D.The photosynthetic activity of the cells was measured by the light dependent 14CO2 incorporation. At 0.5% CO2 the cell suspensions assimilated about 100 μmol CO2/mg chlorophyll × h. In the presence of 1% CO2 the light driven assimilation was raised up to 185 μmol CO2/mg chlorophyll × h. In both cases, the dark incorporation of CO2 was merely 1.8% of the values obtained in light.