758 Hall, Miller, and Herrero 



ethylene for 15 hrs. and upon radioassay were found to have incor- 

 porated approximately 100 cpm/mg of C^^, or a twenty-five fold in- 

 crease. The unused ethylene was again complexed by mercuric-per- 

 chlorate and was stored in the light in a glass vial at ambient tem- 

 peratures for one year in the laboratory. Cotton seedlings were treated 

 in the dark in an enclosed chamber for 15 hrs. with the regenerated 

 ethylene. The treated plants possessed a specific activity of about 

 4,000 cpm/mg, or about a thousand-fold increase in the amount of 

 C^'' incorporated over that from the original "fresh" pure ethylene. 

 Gas chromatography of nonradioactive ethylene and of the original 

 and regenerated samples complexed for various periods of time indi- 

 cate that ethylene is the only main constituent. Only minor amounts 

 of carbon dioxide, which increases with the age of the regenerated 

 ethylene samples, have been detected. The rate of incorporation into 

 cell wall constituents and fixation by plants atypical of carbon di- 

 oxide indicate tentatively that the C^^ from the "aged" samples is 

 not contributed by Ci^02. There is no doubt that C^^ fixation from 

 the "aged" ethylene is increased, but the significance of this must 

 await the results of further tests. 



Water-soluble Metabolites 



Two experiments, one using "fresh" ethylene and the other using 

 "aged" or recovered ethylene, were conducted with Coleiis and cot- 

 ton. After 15 hrs. exposure to ethylene-C^^ the tissues were lyophilized, 

 extracted, fractionated, purified, and the identification of some of the 

 radioactive metabolites attempted by various procedures including 

 column and paper chromatography, radioautography, and conven- 

 tional chemical techniques. In general the radioactive metabolites 

 were the same whether "fresh" or "aged" ethylene was used. Only the 

 "aged" ethylene, however, gave sufficient activity in the metabolites for 

 detailed studies. Therefore, all of the results with metabolites pre- 

 sented in this paper are those obtained using "aged" ethylene. 



During extraction of cotton tissue it was found that one of the 

 major radioactivity-containing fractions was water soluble. The bulk 

 of the total radioactivity, however, remained in the residue and was 

 not extractable by water, ether, alcohol, or other common solvents. 



Characterization of the water soluble radioactive fraction was at- 

 tempted first. Ten grams of lyophilized cotton or Coleus material 

 were extracted by refluxing for two and one-half hrs. with 100 ml. of 

 boiling water. This was followed by four 30-min. successive extractions 

 using 25 ml. of water each time. The total extract was combined to 

 give a final volume of 200 ml. and was used for subsequent fractiona- 

 tions. Aliquots of the stock solution were purified by fractional elu- 



