Biophysics and physiology of temperature regulation in thermogenic flowers.

The flowers or inflorescences of certain primitive seed plants are able to regulate their temperature during blooming by modulating the rate of heat production to remain much warmer than the surroundings. A large drop in ambient temperature causes a smaller drop in flower temperature which causes an increase in the rate of heat production by futile involvement of the cytochrome and alternative oxidase respiratory pathways. The result is that the rate of heat production is inversely related to ambient temperature and flower temperature remains high and relatively independent of ambient temperature. While the biophysics of thermal balance in the whole flowers is better understood, the regulation of the biochemical heat-generating pathways is not known.