Abstract
The elongation of pollen tube is achieved through the continuous apical fusion of vesicles containing cell wall materials and membranes. To study the mechanism of pollen tube elongation, we have focused on the SNAREs, which function as a mediator of fusion between vesicles and target membranes. We generated transgenic plant expressing pollen specific Qa-SNAREs(SYP124,125,131) with GFP-tag under control of their own promoters, and observed the localization of these molecules in pollen grains and tubes. In mature pollen, GFP-SYP 124, 125 and 131 dispersed inside of the cells, suggesting that those are accumulated in some vesicular structure, but not specific organelles. During pollen tube elongation, SYP124 and 125 were highly concentrated on the tip region or proximal region of the pollen tube. However, the localization of SYP131 was uniformly observed in the plasma membrane of pollen tube. These results suggest that different SNARE set are separately used in pollen tube elongation and maintenance.
