The dynamics of the activity of aconitate hydratase (AH, EC 126.96.36.199) in maize leaves under various light regimes was studied and it was established that red and blue light had an inhibitory effect on the functioning of the enzyme under study. Increased activity of AH in dark conditions is associated with activation of respiratory metabolism, as the main source of energy equivalents in the absence of light. The dependence of the expression rate of aco1 and aco2 genes in maize leaves on irradiation with light of different wavelengths is shown. The change in the expression rate of the aco1 gene, depending on the state of the phytochrome and cryptochromic systems, correlates with the activity of the encoded enzyme, indicating a phytochrome- and cryptochrome-mediated mechanism of regulation of the gene mediated. For the aco2 gene, the reverse dependence in phytochrome system regulation is shown.
Key words: aconitate hydratase, cryptochrome, regulation, phytochrome, expression