Effect of Exogenous H_2O_2 on Photosynthetic Characteristics in PEPC Transgenic Rice

To elucidate the physiological mechanism of transgenic rice over expressing C4 photosynthetic genes responds to peroxide stress,the photosynthetic characteristics of the functional leaves net photosynthetic rate Pn,stomatal conductance Gs,intercellular CO2 concentration Ci,transpiration rate Tr and water utilization rate from PEPC transgenic rice and its wild type Kitaake were studied with Li-6400 portable photosynthesis system under different density exogenous H2O2. Net photosynthetic rate of transgenic rice treated with 0. 5-5 mmol/L H2O2 descend as same as changing of stomatal conductance compared to control,and the inhibition are weaken as light intensity increasing. Stomatal conductance of transgenic rice under 50 mmol/L H2O2 treatment is raise but net photosynthetic rate is unchange. Photosynthesis physiological nature of Kitaake under H2O2 concentration gradient are not characteristic like transgenic rice. So 0. 5 mmol/L is effective density to regulate stomatal conductance of transgenic rice,to affect photosynthesis physiological characteristic.