Effect of Dinitrophenol on the Heats of Respiration of Germinating Seeds of Prosopis juliflora, Kochia scoparia, and Oxyria digyna

Abstract

Summtary. During a 36-hour period, the rate of absorpt:on of oxygen, respiration qtuotient, and rate of evolution of heat have been measured tusing seeds of Prosopis ju(liflora, Kochia scoparia, and Oxyriti digyna. The results obtained in pure water were compared with those obtained in dilute solutions of dinitrolphenol. The data appear to be reproducible to + 10 % at the end of the 36-hour period and are independent of the amount of seeds used, provided it was 0.05 g or less. For a given amount of oxygen absorbed, more heat was liberated when the seeds were in a dinitrophenol solution. The results permit an estimate to be made of the heat energy stored in oxidative phosphorylation.It is well known (3) that the germination of seeds is an exothermic process. Calvet and Prat (9) measured the rate of evolution of heat by germinating seeds. Dewez (4) has studied the heat evolution and water uptake of cotton seeds. The investigators used relatively large samples (0. -

Thermogenic Respiration in Aroids

“…Ethylene, like cyanide, often stimulates respiration (1,2). In postharvest fruit respiration (160), the exact role of ethylene is hard to evaluate because of the multiplicity of events (32,103,142,209). However, for intact avocados and for potatoes (where ripening is not at issue) Solomos & Laties (180, 181; cf 33, 154) could show that ethylene and HCN (gas) produce identical responses in glycolysis and respiration.…”

“…The latter type will be referred to as "endogenous uncoupling." Both may lead to an increase in the rate of heat production (103,151,204,205).…”