Abstract
The number of SNARE genes in Arabidopsis genome is much greater than that in any other model organisms. Among them, in addition, many SNARE molecules localize predominantly on the plasma membrane (PM) compared with other intracellular compartments. To elucidate physiological function of each PM-localized SNARE, we analyzed spacio-temporal expression profiling of 9 PM-resident Qa-SNAREs in Arabidopsis roots. One of them, SYP123 showed the specific expression pattern exclusively in the trichoblasts with elongating root hairs. Loss-, or gain-of-function analysis of SYP123 depicted morphological abnormality, or elongation defect in root hairs. These results indicate that SYP123 may function in the elongation step of root hair, not in the bulging phase, and that, furthermore, this Qa-SNARE may control the orientation of polarized vesicular transport by its precise localization on PM of root hair region.
