THE EFFECT OF NEUROTRANSMITTERS ON PROGRAMMED CELL DEATH AND FORMATION OF REACTIVE OXYGEN SPECIES IN THE EPIDERMIS OF PEA LEAVES

Abstract

Neurotransmitters are found not only in animals, but also in other living organisms, including plants. They are found in other living organisms, including plants. However, the data on the functions of these compounds in the plant world are far from being comprehensive. In particular, the issue concerning their impact on plant cell death still awaits further research. In the present work, the effects of neurotransmitters on programmed cell death and the formation of reactive oxygen species (ROS) in plants were tested. Programmed cell death was estimated from the destruction of cell nuclei, and ROS was determined using 2ʹ,7ʹ-dichlorofluorescein. Dopamine, norepinephrine, serotonin, histamine, acetylcholine and its synthetic analog acetylthiocholine were used. The catecholamines dopamine and norepinephrine at concentrations of 0.01-1 mM suppressed the destruction of guard cell nuclei in the epidermis of pea leaves, which was caused by KCN. Serotonin and acetylcholine at a concentration of 1-3 mM, on the contrary, increased the destruction of nuclei that was induced by KCN. Histamine and acetylthiocholine had no effect on KCN-dependent destruction of nuclei at concentrations of 0.01-3 mM. Acetylthiocholine at a concentration of 3 mM, in contrast to natural neurotransmitters, caused the destruction of guard cell nuclei in the absence of KCN. Dopamine, norepinephrine, and serotonin reduced the formation of ROS in the epidermis of pea leaves, which was induced by menadione. Histamine, acetylcholine and acetylthiocholine did not have a similar effect. The results demonstrate that dopamine, norepinephrine and serotonin have antioxidant properties in plants. In addition, dopamine and norepinephrine can prevent cell death.