Achyranthes Bidentata Blume. Responses To UV-B Radiation

Due to human activities,the ozone layer is becoming very thin.Ultraviolet-B radiation has become a major global environment,which can damage plants in terms of growth and molecule.At present,domestic and foreign scholars has done extensive research on the biological effects of ultraviolet-B radiation,but the subjects are concentrated in the area of field crops and ecosystems,not involve medicinal plants.For the most cases,gradient of ultraviolet-B radiation is less.Based on the background above,Study of radiation impacted the growth,physiology and biochemistry,hormones,and genetic expression of Achyranthes bidentata Bl.seeding.The results of this study are as follows: medicinal component1.In the 4 kinds of UV-B radiation conditions,the growth of Achyranthes bidentata Bl seedings significantly inhibited,as follows: dwarf plants,root length shorter,biomass reduced,and with floccosoids leaves;The degree of inhibition is along with intensity of UV-B radiation.The more intense radiation,the higher root shoot ratio.2.SOD and POD activity of two enzymes have shown to deal with than the control at different UV-B radiation.Then CAT activity becomes lower and lower with the radiation time increases.MDA content also becomes more and more along with the radiation time accumulate.H2O2 content that is increased at 1h and2 h treatment than the control and that is reduced at 4h treatment than control.3.Chlorophyll a,chlorophyll b and carotenoid content have all shown to deal with than the control.The longer radiation time is,the deeper degree of reducing is.4.Oleanolic acid and ecdysterone content of Achyranthes bidentata Bl.leaves and roots are increased by UV-B radiation.3h radiation is best for the accumulation of oleanolic acid in leaves and roots,and 4h radiation is best for the accumulation of oleanolic acid in leaves and is not best for that in roots;2hradiation is best for the accumulation of ecdysterone in leaves and roots.5.The key enzyme genes of oleanolic acid and ecdysterone are influenced by UV-B radiation.HMGR?PMK?FPS?SS?SE??-AS and CAS are up-regulated expression,GGPPS is down-regulated expression.6.IAA and GA3 content of Achyranthes bidentata Bl seeding leaves with radiation to enhance and extend the decline in time;And ZR and ABA content with radiation to enhance and increase the extension of time.The changes are aimed at adapt to UV-B radiation,but which is lead to inhibiting growth.7.The key enzyme genes of endogenous hormones are also influenced by UV-B radiation.ASA?PAT1?IGS?TSB?TAR?HMGS?HMGR?PMK?KS and KO are downp-regulated expression.DXS?CMK?ZOGT?N-GT?CKX?DXR?HDR?ABA4?ABA2 and AAO3 are up-regulated expression.