2006/05/26 by Xiu-Fen Song, Xiu‐Fen Song, Chun-Ying Yang +2 · 62 citations
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Arabidopsis #Arabidopsis thaliana #Biochemistry #Biology #Botany #Cell biology #Cellular transport and secretion #Endoplasmic reticulum #GTPase #Gene #Golgi apparatus #Mutant #Plant Molecular Biology Research #Plant Reproductive Biology #Pollen #Pollen tube #Root hair #Tip growth
paper · open access · doi:10.1104/pp.106.077818
published in PLANT PHYSIOLOGY 141(3), 966-976 (Oxford University Press)
openalex publication_date 2006/05/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The polar growth of plant cells depends on the secretion of a large amount of membrane and cell wall materials at the growing tip to sustain rapid growth. Small GTP-binding proteins, such as Rho-related GTPases from plants and ADP-ribosylation factors (ARFs), have been shown to play important roles in polar growth via regulating intracellular membrane trafficking. To investigate the role of membrane trafficking in plant development, a Dissociation insertion line that disrupted a putative ARF GTPase-activating protein (ARFGAP) gene, AT2G35210, was identified in Arabidopsis (Arabidopsis thaliana). Phenotypic analysis showed that the mutant seedlings developed isotropically expanded, short, and branched root hairs. Pollen germination in vitro indicated that the pollen tube growth rate was slightly affected in the mutant. AT2G35210 is specifically expressed in roots, pollen grains, and pollen tubes; therefore, it is designated as ROOT AND POLLEN ARFGAP (RPA). RPA encodes a protein with an N-terminal ARFGAP domain. Subcellular localization experiments showed that RPA is localized at the Golgi complexes via its 79 C-terminal amino acids. We further showed that RPA possesses ARF GTPase-activating activity and specifically activates Arabidopsis ARF1 and ARF1-like protein U5 in vitro. Furthermore, RPA complemented Saccharomyces cerevisiae glo3Delta gcs1Delta double mutant, which suggested that RPA functions as an ARFGAP during vesicle transport between the Golgi and the endoplasmic reticulum. Together, we demonstrated that RPA plays a role in root hair and pollen tube growth, most likely through the regulation of Arabidopsis ARF1 and ARF1-like protein U5 activity.