Effects of Carbonic Anhydrase in Wheat Leaf on Photosynthetic Function Under Low CO_2 Concentration

The response of leaf photosynthetic organelle to low CO 2 concentration (150~180μl/L) treatment was analyzed using common cultivar wheat. The result showed that carbon assimilation rate increased significantly after treatment for 24h, carbonic anhydrase(CA) activity and messaphyll conductance also rose at the same time. The above mentioned change happened mainly in first 24 h after treatment. Actidione treatment inhibited the increase of CA activity and oxygen evolution rate, which exhibited that there existed synthesis of protein in this process. CA special inhibitor acetazolamide also led to the same result, so it was concluded that the increase of CA activity was the main reason for rising of photosynthetic rate . The relationship among low CO 2 concentration inducement, photosynthetic rate of leaves at lower position and high yield was also discussed.