Multiphoton Imaging of the Spatial and Temporal Patterns of Transient Starch and Grana in Arabidopsis Seedling

We took advantage of starch, which emits intense SHG (second harmonic generation) radiation uponthe application of optical excitation sources, to noninvasively monitor germination process of starch in Arabidopsis postembryos for the course of 5 days and some later phases of the seedling development. We presented the temporal and spatial distribution patterns of a whole Arabidopsis seedling in a more natural, noninvasive manner. We can further derive the developmental state of every cell in the seedling. At last we also examined some later phases of the evolution of Arabidopsis to demonstrate that accumulated transient starch is only needed for rapidly developing cells.Next we utilized linearly polarized lights to investigate the interior structure of a chloroplast. As we have already known that SHG is an interactive result of the electric dipoles and the polarized sources, SHG radiation can be generated efficiently when the direction of an electric dipole in the molecule is parallel to the polarization direction of the laser. Therefore we applied this extraordinary property to explore the polarization of grana in an Arabidopsis chloroplast.