The Study About Effect Of UV-B Radiation And He-Ne Laser Enhancement On Apoptosis In The Wheat Seedling

In recent years, induction pathway and regulation mechanism ofplant apoptosis has become a hot issue, by which people study. In thestudy, winter wheat“linyou 2018”as research material Through theinfluence of the radiation of 10.08 kJ·m^-2·d^-1UV-B and laser irradiationof 5mW·mm^-2He-Ne and the combination of the two on the seedings.Screen the best methods of extraction of wheat seedlings’nucleussuitable for analysis by flow cytometry and the modification ofapoptosis on the roots of seeding in different treatment days and eachgroup and related signal transduction and the changeable ofanti-oxygeon system are analized.The results indicate that:（1） MgSO₄buffer works best with integral form and internalstructure and large quantities of the three nuclei extraction buffers ofthe direct shear method;OttoⅠget a remarkable effect on theextraction but after adding OttoⅡthe nuclei brokes obviously, fewer nuclei after adding Tris·MgCl₂buffer. There are too many impuritiesin the nuclei suspension and long time which is made with enzymaticmethod. The result indicates that MgSO₄extration buffer of the directshear method is suitable to analyse DNA content of wheat seedlingsfor flow cytometry.（2） The features of apoptosis are found in the roots of wheatseedling after enhanced UV-B irradiation, such as nuclear assembled,apoptopic bodies.Apoptosis in different treatment groups by flowcytometry are quantitative analized,the results also show that thenumber of apoptosis are increased afer enhanced UV-B irradiationand the differences are obvious in the 5 day. With the management ofUV-B radiation and He-Ne laser, the number of apoptosis less than theUV-B treatment group and decrease obviously. Therefore，theapoptosis of roots of wheat seedling induced by enhanced UV-Bradiation can be remitde partly by He—Ne laser irradiation．（3） O₂.-,H₂O₂and ROS are accumulated after enhanced UV-Bradiation and mitochondrial permeability transition（MPT） isincreasing by UV-B radiation days,meanwhile cytochrome c isreleased and apoptosis iduced.He-Ne laser could decrease thegeneration of ROS and the content of cytochrome c.（4） Enhanced the irradiation of UV-B restrains the activity ofenzyme of anti-oxygeon（POD, CAT and SOD） and the content of anti-oxidant（GSH,ASA）.Stop the gene expression of POD,CAT,SODisoenzyme, enzyme belts are weaken or disappear in differentextents.He-Ne laser has alleviated effect,improve the activity andgene expression of anti-oxygeon system and isoenzyme.