Light-Dependent Expression and Promoter Methylation of the Genes Encoding Succinate Dehydrogenase, Fumarase, and NAD-Malate Dehydrogenase in Maize ( L.) Leaves.

The expression and methylation of promoters of the genes encoding succinate dehydrogenase, fumarase, and NAD-malate dehydrogenase in maize ( L.) leaves depending on the light regime were studied. The genes encoding the catalytic subunits of succinate dehydrogenase showed suppression of expression upon irradiation by red light, which was abolished by far-red light. This was accompanied by an increase in promoter methylation of the gene encoding the flavoprotein subunit A, while methylation was low for encoding the iron-sulfur subunit B under all conditions. The expression of and encoding the anchoring subunits C and D was not affected by red light. The expression of encoding the mitochondrial form of fumarase was regulated by red and far-red light via methylation of its promoter. Only one gene encoding the mitochondrial NAD-malate dehydrogenase gene () was regulated by red and far-red light, while the second gene () did not respond to irradiation, and neither gene was controlled by promoter methylation. It is concluded that the dicarboxylic branch of the tricarboxylic acid cycle is regulated by light via the phytochrome mechanism, and promoter methylation is involved with the flavoprotein subunit of succinate dehydrogenase and the mitochondrial fumarase.