Effect of Light Intensity on Dionaea muscipula Photosynthesis Measured by Action Potential Response Time to Close Trap

Abstract

Photosynthesis particularities such as light intensity and the coupled action potential exhibited visually in a dramatic fashion by Dionaea muscipula is of investigative value. Thisplant’selectrophysiology in the absence of a true nervous system can provide insights into understanding how environmental changes affect all plants in general. We hypothesized that light being a reactant of photosynthesis, greater intensity will lead to greater photosynthetic rate which we were able to quantify by proxy of the action potential response time of Venus flytrap closing. This was done by means of video recording in slow motion and appropriate software analysis tools. The plants were kept in a stable environment with no external light interference or major temperature fluctuations and positioned under LED grow lights set at different light intensities resulting in five treatment conditions with three independent samples. Although statistical analysis by one-way ANOVA suggests no significant difference between the mean response time of the traps closing in the different lighting conditions hence failing to reject our null hypothesis, a suggestive trend was observed with faster response of the plant traps in brighter lighting conditions as was initially predicted and supported by literature. Interestingly, the fastest response time was found to be in the 80% condition which would be around the 6000lux mark leading us to suspect that this is an optimal lighting condition for plants with needs alike D. muscipula’s. At greater light intensities the chlorophyll complex pigments are in higher proportion leading to higher photosynthetic rates (Nelson and Cox) and more pronounced response of the electrical cascade of reactions that generate the plant closing its trap event (Volkov et al.; Trebacz et al.). Nonetheless, our result was not statistically significant and further studies with suggested improvements would need to be conducted to be able to arrive to more confident conclusions and determine the effect of light intensity on the photosynthetic rate of D. muscipula.