A significant effect of soil drought on the gene expression (psaA, psaB, lhca2, psbA, lhcb1 and lhcb4) encoding key structural proteins of reaction centers (RC) and light harvesting complexes (LHC) of photosystems (PS) in barley leaves was shown. A change in the level of gene expression observed under drought conditions is light-dependent — in normal light, there is a significant increase in the expression of lhcb1 (1.6 times), psaA (1.8 times) and psaB (2.5 times) genes, encoding PS I and II proteins, and in the dim light, on the contrary, there is a decrease in the expression of genes encoding the proteins PS II (psbA, lhcb1 and lhcb4) and protein A (psaA) of the PS I RC. It was found that under drought conditions the expression of the gene SOD3 encoding the chloroplast isoform of the antioxidant superoxide
 dismutase (SOD) enzyme Fe-SOD increases multiple times. The data obtained indicate the induction of oxidative stress by drought in the chloroplasts of the leaves of barley plants.