Popov V N, Purvis A C, Skulachev V P, Wagner A M
Department of Plant Physiology and Biochemistry, Voronezh State University, Russia.
Biosci Rep. 2001 Jun;21(3):369-79. doi: 10.1023/a:1013246501917.
We have investigated the influence of stress conditions such as incubation at 4 degrees C and incubation in hyperoxygen atmosphere, on plant tissues. The ubiquinone (Q) content and respiratory activity of purified mitochondria was studied. The rate of respiration of mitochondria isolated from cold-treated green bell peppers (Capsicum annuum L) exceeds that of controls, but this is not so for mitochondria isolated from cold-treated cauliflower (Brassica oleracea L). Treatment with high oxygen does not alter respiration rates of cauliflower mitochondria. Analysis of kinetic data relating oxygen uptake with Q reduction in mitochondria isolated from tissue incubated at 4 degrees C (bell peppers and cauliflowers) and at high oxygen levels (cauliflowers) reveals an increase in the total amount of Q and in the percentage of inoxidizable QH2. The effects are not invariably accompanied by an induction of the alternative oxidase (AOX). In those mitochondria where the AOX is induced (cold-treated bell pepper and cauliflower treated with high oxygen) superoxide production is lower than in the control. The role of reduced Q accumulation and AOX induction in the defense against oxidative damage is discussed.
我们研究了诸如4℃孵育和在高氧环境中孵育等胁迫条件对植物组织的影响。对纯化线粒体的泛醌（Q）含量和呼吸活性进行了研究。从经冷处理的青椒（辣椒属）中分离出的线粒体的呼吸速率超过了对照组，但从经冷处理的花椰菜（甘蓝属）中分离出的线粒体并非如此。高氧处理不会改变花椰菜线粒体的呼吸速率。对从在4℃孵育的组织（青椒和花椰菜）以及高氧水平下（花椰菜）分离出的线粒体中与氧摄取和Q还原相关的动力学数据进行分析，结果显示Q的总量以及不可氧化的QH2的百分比有所增加。这些效应并不总是伴随着交替氧化酶（AOX）的诱导。在那些诱导了AOX的线粒体中（经冷处理的青椒和经高氧处理的花椰菜），超氧化物的产生低于对照组。讨论了还原型Q积累和AOX诱导在抵御氧化损伤中的作用。
