| Phosphoenolpyruvate carboxylase (PEPC),NADP malic enzyme (NADP ME),pyruvate phosphate dikinase (PPDK) and malate dehydrogenase (MDH) are the key enzymes involved in the C4photosynthetic pathway of C4crops.In order to compare the differences in the activities of those key C4enzymes in the development of wheat and foxtail millet and to understand their relationships with photosynthetic rate,4 wheat varieties (China Spring,Jinmai 47,Mianyang 11 and Xiaoyan 6) and 4 millet varieties (Yugu 1,Dungu 1,Jigu 19 and Jigu 20) were used as experimental materials in this study.The activities of those C4enzymes in the leaves of wheat and foxtail millet were determined at the growth stages of seedling,jointing,heading,flowering and grain filling,respectively,and their photosynthetic rates were measured at the corresponding stages using Licor 6400 portable photosynthesis.The results showed that,the activities of the four C4key enzymes were all detected in the leaves of those wheat varieties at different growth stages,which were lower at seedling stage,higher at jointing,heading and flowering stages and lower in grain filling stage for all the four wheat varieties,similar trends were also found in their net photosynthetic rate.The activities of the four C4key enzymes in foxtail millet leaves were much higher than those in wheat leaves.The activities of PPDK and NADP ME in wheat leaves were positively correlated with the net photosynthetic rate at different growth stages,while there were no significant correlations with transpiration rate.The activities of MDH，PEPC and PPDK in foxtail millet leaves were positively correlated with the net photosynthetic rate at different growth stages,while significant correlations were only observe in the PEPC activity in leaves of Yugu 1,and the MDH activity in leaves of Dungu 1 and Jigu 20.with transpiration rate. |
基本信息
