| Abstract [eng] |
VILNIUS UNIVERSITY FACULTY OF NATURAL SCIENCES BIOCHEMISTRY AND BIOPHYSICS DEPARTMENT Olga Sevriukova The investigation of acetylcholine effect on the plant cell membrane electrical parameters applying voltage clamp method Master’s thesis Summary Information transfer in plants, like in all living beings, is one of the main vital processes. Information about the changes of environmental conditions, possible risk, disturbances and many other factors in living systems is transmitted in the form of different signals. Acetylcholine is one of the neurotransmitters, which takes part in transfer of the signals among nerve-cells of animals in the form of action potential. While this material is found also in plants, the aim of this study was to find out, whether it takes part in plants electrogenesis. One of the possible ways to study the cell response to any external stimulus is to register the electrical parameters of cell before and after the signal transmission and evaluate their differences. It is possible to investigate the influence of different materials on plant cell membrane electrical parameters, like ion currents amplitude, dynamics and the current excitation threshold, using voltage-clamp method. This method was used during this study to analyse the influence of acetylcholine on electrical parameters of internodular cells of Nitellopsis obtusa. Such object of investigation as Nitellopsis obtusa is very convenient, because its cells are large enough (up to 10 cm long) and are distinguished by stability of vital processes. Analysis of experimental data obtained has revealed that the Cl- conductance of plant cell membrane, Cl- current amplitude and the duration of inactivation phase increase due to the effect of acetylcholine. Besides, these researches showed that acetylcholine slows down the excitation threshold, latency of the Cl- current activation and the Cl- current reversal potential. What is more it was established that acetylcholine increase the amplitude of Ca2+ current also. In all cases the impact of acetylcholine was reversionary: the elimination of acetylcholine from environment resulted in return of investigated electrical parameters to the value, which was before acetylcholine impact. All these results enable to state that acetylcholine takes part in plant cell electrogenesis, because it has influence on their main electrical excitation mechanisms. |
