Abstract
Plants form sun or shade leaves depending on light environment. Sun leaf shows thicker lamina and higher photosynthetic rate than shade leaf. It was reported that light environment of mature leaves determines whether novel leaf will develop to sun or shade leaf, suggesting existence of long-distance signaling. We hypothesized that this signal may be sugars as products of photosynthesis. To test the hypothesis, we analyzed 3rd-leaves of Arabidopsis plants cultivated on MS-medium with various sucrose concentrations for 14d. Number of cell layers increased with the increase of sucrose content, indicating that sugar affects on leaf development. Next, plants were transplanted to new medium with various sucrose concentrations at 10d after sowing. Number of cell layers was affected only when the plants transplanted to medium with higher sucrose concentration. Thus, leaves have plasticity at this stage. We will also discuss on results of transplantation at 8d and 12d.
