Department of Biology and the Philip L. Boyd Deep Cayon Desert Research Center, University of California, Riverside, California 92502.
Plant Physiol. 1974 Dec;54(6):829-34. doi: 10.1104/pp.54.6.829.
Respiration and gas exchange in the light were studied manometrically with tissue slices from stem material of Opuntia basilaris Engelm. and Bigel. Dark respiration rates were greater in young stems than in mature stems. The timing of the experiment in the day/night cycle influences the magnitude and pattern of respiration and gas exchange in the light. Net dark respiration has a temperature optimum between 35 and 40 C, and is maintained at 60% of the control rate in tissue equilibrated with experimental osmotic potentials of -25 bars. Net gas exchange in the light is regulated by the titratable acidity of the tissue and by the tissue temperature. Increased rates of net CO(2) evolution and net O(2) consumption occur in the light with high levels of titratable acidity and high temperatures. An efflux of CO(2) and influx of O(2) occur following light/dark transitions. These patterns are reversed following dark/light transitions. Similar results were demonstrated at 15, 25, and 35 C, and are interpreted as a mechanism of adaptation to desert environments.
用 Opuntia basilaris Engelm. 和 Bigel. 茎材料的组织切片进行了呼吸作用和气体交换的压力测定研究。与成熟茎相比，年轻茎的暗呼吸速率更高。在昼夜周期中实验的时间会影响光下呼吸作用和气体交换的幅度和模式。在 35 到 40°C 之间，净暗呼吸作用具有最佳温度，并且在与实验渗透压为-25 巴平衡的组织中，以对照速率的 60%维持。在光下，净气体交换受组织可滴定酸度和组织温度的调节。随着可滴定酸度和温度的升高，净 CO2 释放和净 O2 消耗的速率在光下增加。在光/暗转换后会发生 CO2 流出和 O2 流入。在暗/光转换后，这些模式会发生逆转。在 15、25 和 35°C 下也得到了类似的结果，这些结果被解释为适应沙漠环境的一种机制。
