| Popis: |
1. Cotton cotyledon tissue was cultured in inorganic nutrient solutions containing various concentrations of 2,4-D. The nucleic acids and proteins of various cellular components were determined before and after a 48-hour culture period. The phosphatase activity, respiration, and growth rates were also determined. 2. Upon culture most of the RNA in the microsome fraction and about one-half that in the soluble protein was lost. There was an increase of RNA in the chloroplast fraction and little or no change of nucleic acid in the mitochondria and nuclei. There were similar trends for protein changes. 3. At concentrations of 10-4 and 10-3 M, 2,4-D prevented the changes in RNA and protein content. Similar concentrations of 2,4-D stimulated respiration, but the higher resulted in a decreased growth of the tissue as measured by fresh weight. 2,4-D was also found to prevent changes in phosphatase activity during culture of the tissue. |
