Work

Effect of the Absence of α Carbonic Anhydrase 2 on the PSII Light-Harvesting Complex Size in Arabidopsis thaliana

Year: 2025

Type: article

Abstract: The absence of α-carbonic anhydrase 2 (α-CA2) in Arabidopsis thaliana leads to higher contents of chlorophylls a and b, and to a reduced chlorophyll a/b ratio, suggesting an increased PSII antenna compared to wild type (WT). The evaluation of OJIP kinetics of chlorophyll fluorescence in leaves of WT and α-carbonic anhydrase 2 knockout (α-CA2-KO) plants revealed higher apparent photosystem II (PSII) light harvesting antenna size in the mutants. The higher levels of both Lhcb1 and Lhcb2 proteins in α-CA2-KO plants compared to WT plants were demonstrated, using immunoblotting. Gene expression analysis showed an increased lhcb1 expression levels in mutants, whereas lhcb2 and lhcb3 genes were downregulated. The content of hydrogen peroxide (H2O2) in leaves, as well as the production of H2O2 within the thylakoid membranes (“membrane” H2O2) were lower in α-CA2-KO plants as compared with WT plants. The expression levels of the genes encoding regulating proteins, which are involved in retrograde chloroplast-nucleus signaling was lower in α-CA2-KO than in WT. The changes of the PSII light-harvesting complex size in the absence of α-CA2 correlates with decreased accumulation of H2O2 in the leaves of mutants. It is suggested that this led to lower expression levels of the genes related to retrograde signal transduction from the chloroplast to the nucleus. The results of this study support previous conclusions regarding the involvement of α-CA2 in photosynthetic processes and its location within the chloroplasts of Arabidopsis.

Source: Plants

DOI: 10.3390/plants14101529

Authors: Elena M. Nadeeva, Natalia N. Rudenko, Lyudmila K. Ignatova, Daria V. Vetoshkina, Boris N. Ivanov

Institutions: Institute of Basic Biological Problems, Pushchino Scientific Center for Biological Research

Language: English

Topic: Photosynthetic Processes and Mechanisms

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $3,258

Funders: Louisiana State University, Russian Science Foundation, Ministry of Science and Higher Education of the Russian Federation