He-Ne激光对增强UV-B辐射小麦幼苗多胺氧化酶和过氧化物酶活性的研究

采用He-Ne激光辐照对增强UV-B辐射后小麦幼苗的损伤修复作用进行了研究。小麦种子在盛有湿滤纸的培养皿内25℃下进行萌发。萌发后小麦幼苗在经10.08 kJ·m^-2·d^-1的增强UV-B辐射,然后再用5 mW·mm^-2的He-Ne激光进行辐照。通过小麦幼苗叶片游离脯氨酸含量、多胺氧化酶和过氧化物酶的活性变化，测定了He-Ne激光对小麦UV-B损伤的修复情况。结果表明，游离脯氨酸、多胺氧化酶、过氧化物酶的变化同小麦幼苗损伤的修复的能力相关联。He-Ne激光辐照可使由增强UV-B辐射后诱导叶片升高的游离脯氨酸含量降低。增强UV-B辐射对多胺氧化酶（PAO）活性和过氧化物酶（POD）活性呈促进的作用。辐射6 d后PAO和POD总的活性呈正相关性，PAO和POD活性都呈现B组最高，L组最低，且差异显著。显示He-Ne激光对两种酶由于增强UV-B辐照造成的伤害有一定的修复。

The Influence on Peroxidase Activity and Polyamine Oxidase Activity of Leaves in Wheat Seedings Exposed to Enhanced Ultraviolet-B Radiation and Irradiated by He-Ne Laser

The seedlings of wheat were exposed to He-Ne laser irradiation after enhanced UV-B radiated,in order to determine some physiological traits in the damage induced by UV-B radiation. The seeds were cultivated in Petridishes in a constant temperature incubator(25℃)until they were germinated.The germinated seeds were exposed to 10.08 kJ·m^-2·d^-1 UV-B radiation, one by one, and then they were irradiated by He-Ne laser with 5 mW·mm^-2 Power density.Changes about the content of free proline(Pro) and the activity of the peroxidase(POD) and polyamine oxidase(PAO)were measured to test the repair role of laser irradiation. The results showed that the damage of wheat seedlings induced by enhanced UV-B radiation in physiology can be repaired partly by He-Ne laser irradiation with decreasing the content of free Pro and raising the activity of POD and PAO. This is the first investigation reporting the use of laser irradiation treatment to repair the wheat damage induced by UV-B radiation in peroxidase and polyamine oxidaset. It implied that the changes of PAO activity have the relativity with POD in some extent.