Abstract
Phosphoglycolate phosphatase (PGPase) is a key enzyme of photorespiration that catalyzes the conversion of phosphoglycolate into glycolate. PGPase-deficient mutant pgp1 requires elevated levels of CO2 for growth in light. It is possible that carbon-concentration-mechanism (CCM) cannot operate in this mutant because of the accumulation of phosphoglycolate. In order to know how the pgp1 mutation affects the expression of CCM-related genes, we compared the overall expression levels between the mutant and the wild type C9 under low-CO2 condition by using cDNA macroarray. Several genes including Ccp1 encoding the chloroplast envelope protein LIP-36 were not induced under low-CO2 condition. And other genes (e.g. Mca encoding mitochondrial carbonic anhydrase) were identified whose expression levels were lower than that of the wild type under low-CO2 condition. These affected genes were assumed to be regulated by unknown metabolic products, which accumulated in the pgp1 mutant.
