Features of Functioning of Succinate Dehydrogenase and Malate Dehydrogenasein Spinat Leaves <i>Chenopodium foliosum</i> L. and Amaranta <i>Amaranthus caudatus</i> L.in Salt Stress
It was shown that the effect of sodium chloride causes a change in the activity and isoenzyme composition of mitochondrial malate dehydrogenase (MDH), which manifests itself in the induction of an additional isoform in amaranth leaves (C<sub>4</sub>-type). It was noted that in spinach plants (C<sub>3</sub>-type), salinization does not cause significant changes in the activity of the studied enzymes and isoenzyme composition, the activity of succinate dehydrogenase (SDH) in amaranth leaves during salinity increases several times. the isoenzyme composition of SDH in plant leaves remains unchanged. It was found that the levels of gene transcripts clearly correlate with changes in the activity of MDH and SDH in amaranth and spinach leaves, and in salt stress it enhances the expression of <i>mdh-mtx</i> (mitochondrial) and <i>mdh-cyt</i> (cytoplasmic) genes in amaranth leaves throughout the experiment. For the <i>sdha</i> gene, a decrease in the content of transcripts was found, which clearly correlates with a decrease in the activity of SDH.