中国科学C辑(英文版)
中國科學C輯(英文版)
중국과학C집(영문판)
SCIENCE IN CHINA (Series C)
2003年
4期
438-446
,共9页
焦德茂%匡廷云%李霞%戈巧英%黄雪清%郝乃斌%白克智
焦德茂%劻廷雲%李霞%戈巧英%黃雪清%郝迺斌%白剋智
초덕무%광정운%리하%과교영%황설청%학내빈%백극지
PEPC transgenic rice%phosphoenopyruvate carboxylase (PEPC)%carbonic anhydrase (CA)%stomatal conductance%CO2 concentrating mechanism
The relationship between carbon assimilation and high-level expression of the maize PEPC in PEPC transgenic rice was studied by comparison to that in the untransformed rice, japonica kitaake. Stomatal conductance and photosynthetic rates in PEPC transgenic rice were higher than those of untransformed rice, but the increase of stomatal conductance had no statistical correlation with that of photosynthetic rate. Under high levels of light intensity, the protein contents of PEPC and CA were increased significantly. Therefore the photosynthetic capacity was increased greatly (50%) with atmospheric CO2 supply. While CO2 release in leaf was reduced and the compensation point was lowered correspondingly under CO2 free conditions. Treatment of the rice with the PEPC-specific inhibitor DCDP showed that overexpression of PEPC and enhancement of carbon assimilation were related to the stability of Fv/Fm. Labeling with 14CO2 for 20 s showed more 14C was distributed to C4 primary photosynthate asperate in PEPC transgenic rice, suggesting that there exists a limiting C4 photosynthetic mechanism in leaves. These results suggest that the primitive CO2 concentrating mechanism found in rice could be reproduced through metabolic engineering, and shed light on the physiological basis for transgenic breeding with high photosynthetic efficiency.