Umekawa Yui, Seymour Roger S, Ito Kikukatsu
United Graduate School of Agricultural Science, Iwate University, 3-18-8 Ueda, Morioka, Iwate, 020-8550, Japan.
School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia.
Sci Rep. 2016 Apr 20;6:24830. doi: 10.1038/srep24830.
Thermoregulation (homeothermy) in animals involves a complex mechanism involving thermal receptors throughout the body and integration in the hypothalamus that controls shivering and non-shivering thermogenesis. The flowers of some ancient families of seed plants show a similar degree of physiological thermoregulation, but by a different mechanism. Here, we show that respiratory control in homeothermic spadices of skunk cabbage (Symplocarpus renifolius) is achieved by rate-determining biochemical reactions in which the overall thermodynamic activation energy exhibits a negative value. Moreover, NADPH production, catalyzed by mitochondrial isocitrate dehydrogenase in a chemically endothermic reaction, plays a role in the pre-equilibrium reaction. We propose that a law of chemical equilibrium known as Le Châtelier's principle governs the homeothermic control in skunk cabbage.
动物的体温调节（恒温性）涉及一种复杂机制，该机制包括遍布全身的热感受器以及下丘脑的整合作用，下丘脑控制着颤抖和非颤抖产热。一些古老的种子植物科的花朵表现出相似程度的生理体温调节，但机制不同。在这里，我们表明，臭菘（Symplocarpus renifolius）恒温佛焰花序中的呼吸控制是通过限速生化反应实现的，其中整体热力学活化能呈现负值。此外，在化学吸热反应中由线粒体异柠檬酸脱氢酶催化的NADPH生成在预平衡反应中起作用。我们提出，一种称为勒夏特列原理的化学平衡定律支配着臭菘的恒温控制。
