School of Biological Sciences, University of Adelaide, Adelaide, South Australia, 5005, Australia.
Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, Iwate, 020-8550, Japan.
Plant Cell Environ. 2018 Feb;41(2):367-373. doi: 10.1111/pce.13097. Epub 2017 Nov 27.
The respiration rate of the thermogenic inflorescences of Japanese skunk cabbage Symplocarpus renifolius can reach 300 nmol s g , which is sufficient to raise spadix temperature (T ) up to 15 °C above ambient air temperature (T ). Respiration rate is inversely related to T , such that the T achieves a degree of independence from T , an effect known as temperature regulation. Here, we measure oxygen consumption rate (Ṁo ) in air (21% O in mainly N ) and in heliox (21% O in He) to investigate the diffusive conductance of the network of gas-filled spaces and the thermoregulatory response. When T was clamped at 15 °C, the temperature that produces maximal Ṁo in this species, exposure to high diffusivity heliox increased mean Ṁo significantly from 137 ± 17 to 202 ± 43 nmol s g FW, indicating that respiration in air is normally limited by diffusion in the gas phase and some mitochondria are unsaturated. When T was clamped at 15 °C and T was allowed to vary, exposure to heliox reduced T 1 °C and increased Ṁo significantly from 116 ± 10 to 137 ± 19 nmol s g , indicating that enhanced heat loss by conduction and convection can elicit the thermoregulatory response.
日本白屈菜雄花序的呼吸速率可达 300 nmol s g ，足以将佛焰苞温度 (T ) 升高到比环境空气温度 (T ) 高 15°C 。呼吸速率与 T 呈反比，使 T 达到一定程度的独立于 T ，这种效应被称为温度调节。在这里，我们测量了空气中（21% O 在主要为 N 中）和氦氧混合气中（21% O 在 He 中）的耗氧量 (Ṁo ) ，以研究充满气体的空间网络的扩散导率和热调节反应。当 T 被夹在 15°C 时，这一物种产生最大 Ṁo 的温度，暴露在高扩散性的氦氧混合气中，使平均 Ṁo 从 137±17 显著增加到 202±43 nmol s g FW ，表明在空气中呼吸通常受到气相扩散的限制，一些线粒体不饱和。当 T 被夹在 15°C ，T 可以变化时，暴露在氦氧混合气中使 T 降低 1°C ，并使 Ṁo 显著从 116±10 增加到 137±19 nmol s g ，表明通过传导和对流增强热损失可以引发热调节反应。
