摘要
在提取玉米和大豆线粒体后，以ABA处理线粒体，发现在不同底物存在下，ABA均可增加线粒体的耗氧速率，呼吸速率随ABA浓度变化的结合常数（Kd）值为1．43μmol／L。ABA对4态呼吸的促进作用更为显著，因而导致呼吸控制下降，P／O比降低。蛋白质合成抑制剂环己酰亚胺不影响ABA的效应。以ABA预处理大豆子叶，虽然也促进了呼吸作用，但不改变呼吸控制和P／O.
When isolated mitochondria were treated with different concentrations(l ~ 100 μmol/L) of abscisic acid(ABA), the O2 uptake of mitochondria were stimulated even if beated by 2μmol/L ABA (Fig. 1 ). The effect ofABA on the rate of respiration exhibited Michaelis-Menten kinetics, with a Kdvalue of 1. 43 μmol/L (Fig. 2). Therespiration of mitochondria isolated frommaize and soybean was all stimulated byABA (Figs. 3 and 5). The effect ofABA was stronger on state 4 than onstate 3, signffying that it induced a decrease in respiratory control (RC) andP/O (Table 1 ). The 'break' temperature of the Arrhenius Plot for respirationrate and P/O rate was also lowered byABA treatment (Fig. 4). 10 μg/ml cycloheximide (CHI) did not influence theeffect of ABA on respiration rate (Table2). Pretreatment of soybean with ABAbefore the isolation of mitochondria ,respiration rate of mitochondria increased(Fig. 6). The mechanism of the effectof ABA on respiration has been discussed.
基金
国家自然科学基金
