Abstract
In higher plants, vesicular traffic plays important roles in plant functions and development. Rab GTPases, key regulators of vesicle transport, have been widely conserved among eukaryotes. Among these Rabs, the Rab5 group, which consists of RHA1, ARA7 and ARA6 in Arabidopsis thaliana, regulates endocytosis.
To investigate their roles in plant development, we analyzed T-DNA tagged knockout Arabidopsis lines. Although each single KO had no obvious phenotype, the rha1-/- ara7-/- double mutant was never segregated. Cross-pollination analysis revealed that the double KO was male gamete lethal. Structural analysis of the rha1-ara7- pollen by light and electron microscopy showed abnormal callose depositions within the pollen grain, indicating that ARA7 and RHA1 might have important function during the pollen development.
