摘要： 为阐释转C4 PEPC光合基因水稻过氧化物胁迫条件下的光合生理特性,以转PEPC基因水稻(PC)、未转基因原种(Kitaake)为材料,运用Li-400便携式光合仪观测其在不同浓度外源H2O2处理下的净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、蒸腾速率(Tr)以及水分利用率等光合参数的变化.结果发现,与未用H2O2处理的PC相比,PC在0.5~5 mmol/L H2O2浓度处理下,其Pn在不同光强下均表现下降,与其Gs的下降一致,这个抑制过程随光强的增加而减弱,而50 mmol/L H2O2处理下PC,虽Gs增加,但是其Pn并没有增加,表现不同H2O2的浓度效应;而未转基因水稻则没有上述表现,推测PC可能通过低浓度的H2O2参与气孔运动的调节,从而影响其光合特性.

关键词: 水稻, C4 PEPC基因, 净光合速率, 气孔导度

Abstract: 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.

Key words: Rice, C₄ PEPC gene, Net photosynthetic rate, Stomatal conductance

中图分类号: 

• S511.01