CO2 stress and CO2 concentration mechanism: investigation by means of photosystem-deficient and carbonic anhydrase-deficient mutants of Chlamydomonas reinhardtii

• Published in: Photosynthetica Vol. 28
• Main Authors: Pronina N.A, Borodin V.V
• Format: Journal Article
• Language: English
• Published: 1993
• Subjects: actividad enzimatica; activite enzymatique; agar; agar agar; algae; carbon dioxide; carbonate dehydratase; carbonate deshydratase; carbonato deshidratasa; dioxido de carbono; dioxyde de carbone; echange gazeux; enzymic activity; estres; fotosintesis; gas exchange; gelose; intercambio de gases; mutant; mutantes; mutants; oxigeno; oxygen; oxygene; photosynthese; photosynthesis; stress
• ISSN: 0300-3604; 1573-9058

Activity of carbonic anhydrase (CA) was studied in wild type (WT) Chlamydomonas reinhardtii and five mutants distinguished only by retaining photosystem 1 (PS 1), photosystem 2 (PS 2), light-harvesting complexes (LHC) of PS 1 or PS 2 and both photosystems without LHC. Two forms of CA, soluble CA (sCA) and membrane-bound (mbCA), were found in the cells. The highest activity of mbCA was observed in mutants which retained both photosystems, or only PS 1 and PS 2. The mutants deprived of photosystems but retaining LHC almost lacked mbCA. Thus, there was a correlation between the retention of mbCA and mutant abilities to perform the photosynthesis. Photosynthetic characteristics of the high CO2 requiring mutant of C. reinhardtii CIA-3 were compared with those of WT grown at 2 % CO2 and after various times of exposure to limiting CO2 concentration (0.03 %).