Characteristics of tolerance to photoinhibition and photooxidation characteristics in PEPC transgenic rice

Changes of chlorophyll fluorescence parameters and other indexes in transgenic rice and its wild tpye were studied under photoinhibition and phooxidation conditions.Results showed that PEPC activity increased significantly after the introduction of PEPC gene from maize into rice.Photoinhibition of photosynthesis existed at noon in different genotypes under natural condition with high light and high temperature in which Fv/Fm,qP and PSⅡ reduced less and qN increased less in PEPC transgenic rice.Thus the efficiency of light energy transferring to chemical energy was higher and the thermal energy dissipation was lower.It was tolerant to photoinhibition.Under photooxidation,the content of chlorophyll and protein reduced less in PEPC transgenic rice,which demonstrated it was tolerant to photooxidation.At the same time,Fv/Fm and qP reduced less and qN increased more in PEPC transgenic rice,which showed that it enhanced tolerance to photooxidation through the higher efficiency of light energy transferring to chemical energy and the thermal energy dissipation.