The Role of Methylation of CpG Islands of the csy3 Gene Promotor in the Light Regulation of ATP-Citrate Lyase Activity in Maize Leaves

Abstract

It was established that the functioning of ATP-citrate lyase in maize (Zea mays L.) leaves is regulated by the light conditions of plants, in particular, irradiation of maize plants with red or blue light caused a sharp increase in enzyme activity compared with the “darkness-” and irradiation with far-red light variants. It was shown that active forms of phytochrome and cryptochrome are involved in increase of ATP-citrate lyase activity by regulating the expression of the csy3 gene. This was probably achieved by interacting with a specific G-site of the csy3 gene promoter. Analysis of the nucleotide sequence of the ATP-citrate lyase gene promoter showed the presence of CpG islands, providing the potential for methylation. The study of the methylation status of individual CG dinucleotides of the csy3 gene promoter revealed a change of this index depending on the conditions of the light regime in plants. A high degree of methylation of CG dinucleotides in the csy3 gene promoter resulted in a decrease in the level of transcripts of this gene, and, as a result, inhibition of ATP-citrate lyase activity in the dark and during irradiation with far-red light.