Regulation of Glutamate Dehydrogenase Activity in Maize Leaves (Zea mays L.) with Change in the Light Сonditions

The molecular and biochemical mechanisms of regulation of the activity of glutamate dehydrogenase (GDH) in maize leaves were studied when the light regime was changed. The intracellular distribution of glutamate dehydrogenase activity was established, which showed that this enzyme is located mainly in mitochondria (86%). It was revealed that the magnitude of the GDH activity is regulated by the light regime. In the dark and under irradiation with far red light (FRL), glutamate dehydrogenase activity increases, which is due to the activation of the expression of genes encoding the α-subunit ( gdh-2 ) and β-subunit ( gdh-1 ). The level of transcripts of genes gdh-1 , gdh-2 , encoding various subunits of this enzyme, increased in the dark, but decreased in the light and upon irradiation with red light. It was shown that the transduction of the phytochrome signal is carried out with the participation of a secondary messenger—calcium cations.