Venus flytrap biomechanics: forces in the Dionaea muscipula trap.

Biomechanics of morphing structures in the Venus flytrap has attracted the attention of scientists during the last 140 years. The trap closes in a tenth of a second if a prey touches a trigger hair twice. The driving force of the closing process is most likely due to the elastic curvature energy stored and locked in the leaves, which is caused by a pressure differential between the upper and lower layers of the leaf. The trap strikes, holds and compresses the prey. We have developed new methods for measuring all these forces involved in the hunting cycle. We made precise calibration of the piezoelectric sensor and performed direct measurements of the average impact force of the trap closing using a high speed video camera for the determination of time constants. The new equation for the average impact force was derived. The impact average force between rims of two lobes in the Venus flytrap was found equal to 149 mN and the corresponding pressure between the rims was about 41 kPa. Direct measurements of the constriction force in the trap of Dionaea muscipula was performed during gelatin digestion. This force increases in the process of digestion from zero to 450 mN with maximal constriction pressure created by the lobes reaching to 9 kPa. The insects and different small prey have little chance to escape after the snap of the trap. The prey would need to overpower the "escaping" force which is very strong and can reach up to 4N.

Circadian rhythms in biologically closed electrical circuits of plants.

The circadian clock regulates a wide range of electrophysiological and developmental processes in plants. Here, we discuss the direct influence of a circadian clock on biologically closed electrochemical circuits in vivo. The biologically closed electrochemical circuits in the leaves of C. miniata (Kaffir lily), Aloe vera and Mimosa pudica, which regulate their physiology, were analyzed using the charge stimulation method. Plants are able to memorize daytime and nighttime. Even at continuous light or darkness, plants recognize nighttime or daytime and change the input resistance. The circadian clock can be maintained endogenously and has electrochemical oscillators, which can activate ion channels in biologically closed electrochemical circuits. The activation of voltage gated channels depends on the applied voltage, electrical charge, and the speed of transmission of electrical energy from the electrostimulator to plants.

Circadian rhythms in electrical circuits of Clivia miniata.

The biological clock regulates a wide range of physiological processes in plants. Here we show circadian variation of the Clivia miniata responses to electrical stimulation. The biologically closed electrochemical circuits in the leaves of C. miniata (Kaffir lily), which regulate its physiology, were analyzed in vivo using the charge stimulation method. The electrostimulation was provided with different voltages and electrical charges. Resistance between Ag/AgCl electrodes in the leaf of C. miniata was higher at night than during the day or the following day in the darkness. The biologically closed electrical circuits with voltage gated ion channels in C. miniata are activated the next day, even in the darkness. C. miniata memorizes daytime and nighttime. At continuous light, C. miniata recognizes nighttime and increases the input resistance to the nighttime value even under light. These results show that the circadian clock can be maintained endogenously and has electrochemical oscillators, which can activate voltage gated ion channels in biologically closed electrochemical circuits. The activation of voltage gated channels depends on the applied voltage, electrical charge and speed of transmission of electrical energy from the electrostimulator to the C. miniata leaves. We present the equivalent electrical circuits in C. miniata and its circadian variation to explain the experimental data.