Carbonic Anhydrases in Photosynthesizing Cells of C3 Higher Plants

Abstract

The review presents data on the location, nature, properties, number, and expression of carbonic anhydrase genes in the photosynthesizing cells of C3 plants. The available data about the presence of carbonic anhydrases in plasma membrane, cytoplasm, mitochondria, chloroplast stroma and thylakoids are scrutinized. Special attention was paid to the presence of carbonic anhydrase activities in the different parts of thylakoids, and on collation of sources of these activities with enzymes encoded by the established genes of carbonic anhydrases. The data are presented to show that the consistent incorporation of carbonic anhydrases belonging to different families of these enzymes forms a coherent system of CO2 molecules transport from air to chloroplasts in photosynthesizing cells, where they are included in organic molecules in the carboxylation reaction. It is discussed that the manifestation of the activity of a certain carbonic anhydrase depends on environmental conditions and the stage of ontogenesis.

Physiological and Proteomic Signatures Reveal Mechanisms of Superior Drought Resilience in Pearl Millet Compared to Wheat

“…Carbonic anhydrase (CA) and phosphoenolpyruvate carboxylase (PEPC) are two important enzymes at the beginning of the C 4 carbon fixation process and may be directly related to photosynthesis efficiency. They both are located in the cytosol of mesophyll cells, whereas in C 3 plants, they are predominantly located in chloroplast stroma ( Ignatova et al, 2019 ). CA at the proteome level showed decreased levels under stress condition compared to controls in both the genotypes of pearl millet (Pgl_GLEAN_10019649, Pgl_GLEAN_10007313, Pgl_GLEAN_10019645).…”

Thiol Redox Regulation of Plant β-Carbonic Anhydrase

“…While such an increase in photosynthetic rate may justify the expression of βCA to increase competitiveness and fitness, thiol switching appears unnecessary. Other authors assign a role to βCA in pH homeostasis, chloroplast lipid metabolism, pathogen defense, and seedling survival (reviewed by [48]). Interestingly, a certain fraction of chloroplast CA is associated with the thylakoid membrane where it interferes with photosystem II [49].…”

“…Interestingly, a certain fraction of chloroplast CA is associated with the thylakoid membrane where it interferes with photosystem II [ 49 ]. Inhibitors of CA such as acetazolamide and ethoxyzolamide also inhibit photosystem II [ 48 ]. This observation was explained by the protective effect of HCO 3 − on the oxygen evolving complex [ 50 ].…”

Chloride involvement in the synthesis, functioning and repair of the photosynthetic apparatusin vivo

“…For the PSII‐associated carbonic anhydrase(s) (Ignatova et al , 2019a,b), Cl − ‐depleted thylakoids and PSII particles of Zea mays have their carbonic anhydrase activity increased by the addition of Cl − up to 30 mol m −3 , with inhibition at higher concentrations (Stemler, 1986; Lu & Stemler, 2002). Lu & Stemler (2002) suggest that carbonic anhydrase activity is associated with the oxygen evolving complex 33 (OEC33 = psbO) protein, although this was not confirmed by Ignatova et al .…”

“…Lu & Stemler (2002) suggest that carbonic anhydrase activity is associated with the oxygen evolving complex 33 (OEC33 = psbO) protein, although this was not confirmed by Ignatova et al . (2019a,b) for C 3 flowering plants, including S. oleracea .…”