Increased expression of mitochondria-localized carbonic anhydrase activity resulted in an increased biomass accumulation in Arabidopsis thaliana

摘要

Carbonic anhydrase (CA; EC 4.2.1.1) catalyzes the interconversion of CO2 and HCO3 (-) and plays an important role in photosynthetic carbon assimilation. We report that the effect of manipulating At beta CA6 expression on the growth and biomass accumulation of Arabidopsis thaliana shows that At beta CA6 was expressed in mitochondria. Overexpression of At beta CA6 increased the fresh weight, dry weight and rosette leaf area and it was also linked to a slight decrease in the rate of respiration. By contrast, when the respiration rate in the At beta CA6 knock-out mutant SALK_065611 increased, the fresh weight, dry weight and rosette leaf area decreased. The expression level of At beta CA6 mainly affected the expression of the genes that were related to metabolism, photosynthesis and respiration. We discuss these data with respect to a potential role of At beta CA6 in refixation of CO2 released from respiration and its potential as an option to increase biomass production.