Participation of Two Carbonic Anhydrases of the Alpha Family in Photosynthetic Reactions in Arabidopsis thaliana

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E. M. Zhurikova, L. K. Ignatova, N. N. Rudenko, V. A. Mudrik, D. V. Vetoshkina, and B. N. Ivanov^*

Institute of Basic Biological Problems, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia; E-mail: ivboni@rambler.ru

^* To whom correspondence should be addressed.

Received July 11, 2016; Revision received July 20, 2016

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The expression of genes of two carbonic anhydrases (CA) belonging to the α-family, α-CA2 and α-CA4 (according to the nomenclature in N. Fabre et al. (2007) Plant Cell Environ., 30, 617-629), was studied in arabidopsis (Arabidopsis thaliana, var. Columbia) leaves. The expression of the At2g28210 gene coding α-CA2 decreased under increase in plant illumination, while the expression of the At4g20990 gene coding α-CA4 increased. Under conditions close to optimal for photosynthesis, in plants with gene At2g28210 knockout, the effective quantum yield of photosystem 2 and the light-induced accumulation of hydrogen peroxide in leaves were lower than in wild type plants, while the coefficient of non-photochemical quenching of leaf chlorophyll a fluorescence and the rate of CO₂ assimilation in leaves were higher. In plants with At4g20990 gene knockout, the same characteristics changed in opposite ways relative to wild type. Possible mechanisms of the participation of α-CA2 and α-CA4 in photosynthetic reactions are discussed, taking into account that protons can be either consumed or released in the reactions they catalyze.

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KEY WORDS: photosynthesis, carbonic anhydrase, arabidopsis, gene expression, mutants

DOI: 10.1134/S0006297916100151

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