Analysis of the effects of cerium on calcium ion in the protoplasts of Arabidopsis thaliana with confocal microscopy
The laser-scanning confocal microscopy has become a routine technique and indispensable tool for cell biological studies. In this study, the probe Fluo-3 AM was used to research the instantaneous changes of calcium ion (Ca2+) in the protoplasts of Arabidopsis thaliana. The laser-scanning mode of confocal microscope is XYT, and the time interval between two images is 10.635 s. 30 optical sections were acquired with the laser-scanning confocal microscope, and the different concentrations of trivalent cerium (Ce3+) (0.1, 0.5 and 1.0 mmol/L) were added after four optical sections were scanned, respectively. Furthermore, the fluorescence intensity of Ca2+ in the 30 optical sections was quantified with Leica Confocal Software. The quantitative data was exported and the trend chart was made with Excel software. The results indicate that Ca2+ concentration in the protoplasts of A. thaliana declined after 0.5 and 1.0 mmol/L Ce3+ was added. However, Ca2+ concentration slightly increased in the protoplasts treated with 0.1 mmol/L Ce3+. The data indicate that the appropriate amount of Ce3+ can inhibit intracellular Ca2+ concentration in the protoplasts of A. thaliana. Since Ca2+ participates in signal transduction and plays a crucial role in regulating plant growth and development under environmental stresses, Ce3+ may regulate plant metabolism, growth and development via the changes of Ca2+ concentration.
Key words: Cerium, calcium ion, protoplast, confocal microscope.