烟草愈伤组织继代培养期间呼吸途径与活性氧水平动态变化

Dynamic changes of respiration pathway and active oxygen levels in subcultured tobacco callus.

继代培养期间的烟草愈伤组织总呼吸速率分别在第 11天和第 19天出现两次跃升 ,同时抗氰呼吸的发生与运行逐渐加强 ,在两呼吸高峰之间达到极大值 ,随后则逐渐下降 ,但愈伤组织的电子传递仍以细胞色素途径为主 .通过对愈伤组织衰老过程中活性氧代谢变化分析 ,发现抗氰呼吸发生与H2 O2 含量 ,其实际运行则与O-2· 含量呈平行关系 ,但交替途径容量的降低则与·OH含量显著上升紧密相关 ,用活性氧清除剂处理愈伤组织也得到上述相似的结果 .由此推测愈伤组织在衰老过程中产生的活性氧诱导抗氰呼吸参与烟草愈伤组织起始衰老 .

During the growth and senescence of tobacco callus, the total respiration rate showed two peaks on the 11th and 19th day,respectively. The development and operation of alternative pathway increased gradually,reached the maximum between two respiration peaks,and then declined in the following days, but the cytochrome pathway was still as a main electron transport pathway consistently. Analysis on the levels of active oxygen species during the growth and senescence process in tobacco callus suggested that H 2O 2 and O - 2· were involved in some way in the induction of the development and operation of the alternative pathway,but the increase of production rate of OH might suppress both the development and operation of the alternative pathway, which were enhanced by H 2O 2 and O - 2· respectively. These results were further proved by the use of active oxygen scavengers. The possible participation of the alternative pathway enhanced by active oxygen in the initial senescence process was discussed.