The Study Of Regulation Of ROS Levels In Rice Seedling By SOD Model Compounds

Reactive oxygen species(ROS) are continuously produced in plants as by products of aerobic metabolism,and are removed by means of antioxidants and antioxidative enzymes.In recent years,it has become apparent that ROS are versatile signal molecules mediating a variety of cellular responses in plant cells,including development, gravitropism,and hormone signaling,response to biotic and abiotic environmental stimuli,and programmed cell death.The rice seeds are treated with mimicking metalloenzymes.Then,the contents of reactive oxygen species in rice under drought stress are investigated by the UV-visable spectrometer,fluorescence spectrophotometer,histochemistry and confocal laser scanning microscope.And the activities of antioxidant enzymes in rice leaf are measured by the UV-visable spectrometer.1 The contents of superoxide free radical(O₂^-),hydrogen peroxide(H₂O₂) and hrdroxyl radicals are investigated by the UV-visable spectrometer,fluorescence spectrophotometer.The results indicated that the content of ROS in treated rice is lower than the control rice under drought stress.2 The production of hydrogen peroxide(H₂O₂) and superoxide free radical(O₂^-) in rice leaves are studied by histochemistry with diaminobenzidine(DAB) and nitroblue tetrazolium(NBT),respectively.The results indicated that The H₂O₂ and O₂^-accumulation in rice leaf could be weakened by the mimicking metalloenzymes under drought stress.3 The H₂O₂ formation in the root-tips was detected by the infiltration of 2',7'-dichlorodihydrofluorescein diacetate(H₂DCFDA) using fluorescence microscope and CLSM.Fluorescent staining revealed that H₂O₂ accumulation in the root tips of treated rice is smaller than those of the control group under drought stress.4 The activities of antioxidant enzymes in rice leaf are measured by the UV-visable spectrometer.The results indicated that The activities of four antioxidant enzymes(SOD,CAT,APX,GR) in treated rice are higher than the control rice under drought stress.