The role of carbonic anhydrase α-CA4 in the adaptive reactions of photosynthetic apparatus: the study with α-CA4 knockout plants

Role of Plant Carbonic Anhydrases under Stress Conditions

“…The content of the major PSII antenna proteins, Lhcb1, and Lhcb2 was lower in α-CA4 knockouts than in the WT plants. We have also found that the mutant plants grown under high illumination compensated for the absence of α-CA4 and for reduced NPQ by the increase in the contents of both PsbS protein and the violaxanthin cycle components, the latter accompanied by an increase in violaxanthin deepoxidase activity [13]. In addition, α-ca4 gene was found among the genes that change the expression level under osmotic stress [136].…”

“…We have shown that the fresh weight of the plant leaves with knocked-out α-ca4 gene was 10% higher, the starch and H 2 O 2 content was significantly higher, and the rate of CO 2 assimilation in leaves was lower in comparison to WT plants. The effective quantum yield of photosynthetic electron transport at saturating light intensity and CO 2 concentration was higher in mutants than in the WT, while nonphotochemical chlorophyll fluorescence quenching (NPQ ) was lower [13,37,134,135]. The content of transcripts of the At4g20990 gene encoding α-CA4 was two times higher under high (400 μmol quanta m −2 s −1 ) than under low illumination (80 μmol quanta m −2 s −1 ) when grown under "short-day" (8 hours day/16 hours night) and 16 times higher under "long-day" conditions (16 hours day/8 hours night) [6].…”

“…Recent studies show that the CAs are important not only for photosynthesis and for a number of metabolic pathways, including the interconversion of Ci forms, but also they are necessary under certain stress conditions. In this case, changes (fluctuations) in the CA activity can orchestrate the intensity of certain metabolic processes including the rate of photosynthesis [11][12][13].…”

The Role of Carbonic Anhydrase αCA4 in Photosynthetic Reactions in Arabidopsis thaliana Studied, Using the Cas9 and T-DNA Induced Mutations in Its Gene

“…in [ 5 ]). There are data on the CAs and CA activity in thylakoids of higher plants [ 6 , 7 , 8 , 9 , 10 , 11 ]. One of them is αCA4, the protein encoded by the At4g20990 gene, which was found after the proteomic analysis of the proteins from Arabidopsis thylakoid membranes [ 12 ].…”

“…In our previous studies, it has been discovered that the At4g20990 ( αCA4 ) gene knockout in T-DNA induced mutants of Arabidopsis led to a decrease in non-photochemical quenching of chlorophyll a fluorescence (nPQ) in leaves [ 6 , 7 , 10 , 14 ]. This parameter reflects several processes, which lead to a decrease of the solar energy input into reaction centers of photosystems, first in Photosystem II (PSII).…”