Abstract
In higher plants, vesicle traffic plays important roles in plant functions such as auxin polar transport, gravitropic
response and cytokinesis. Rab GTPases, key regulator of vesicle transport, have been widely conserved among eukaryotes and Arabidopsis thaliana has 57 Rab members in the genome. Among these Rabs, the Rab5 group, which consists of ARA7, RHA1 and ARA6, regulates endocytosis. To investigate their roles in whole plants, we tried to analyze T-DNA tagged knockout Arabidopsis lines. We found that each single KO had no obvious phenotype but the ara7-/- rha1-/- double mutant was not segregated indicating that it is lethal. Cross-pollination analysis revealed that the double mutant is male gamete lethal. Now we are performing structural and functional analysis of the mutant pollen. From these results we will discuss the roles of plant Rab5 in pollen development and its function.
