Effects of Some Chemical Compounds on the Slow, Far-red Induced Afterglow from Leaves of Elodea and the Lack of Effect of N-methyl Phena zonium Methosulfate on Far-red induced Glucose Uptake in Chlorella

N-methyl phenozonium methosulfate,3–(3,4-dichlorophe-nyl)–l, l-dimethylurea and carbonylcyanide-m-chlorophenyl hydrazone have similar effects on the slow, far-red induced afterglow component in intact Elodea leaves as has previously been shown for Chlorella. The first compound increases the rate constant for emission. Contrary to the case with Chlorella, it also markedly increases the total amount of light emitted from 10 sec. to infinity (maximally by 50 percent). The second compound decreases the rate constant and the amount of light, and the third compound increases the rate constant and decreases the amount of light. Electron micrographs are compared with the hypothetical units that can be deduced from the afterglow experiments, and it is found that the small thylakoids (“grana thylakoids”) have a size of the same order of magnitude as that expected for the afterglow units. The afterglow from Elodea, in contrast to that from Chlorella, is not affected by desaspidin except at extremely high concentrations. Far-red induced glucose uptake in Chlorella is not affected by 10^–7M N-methyl phenazonium methosulfate, which was previously shown to have a large effect on afterglow kinetics in the same organism.