ATP binding cassette (ABC) transporters transport diverse substrates across membranes in various organisms. However, plant ABC transporters have only been scantily characterized. By taking advantage of the auxin-sensitive Arabidopsis thaliana root hair cell and tobacco (Nicotiana tabacum) suspension cell systems, we show here that Arabidopsis P-glycoprotein4 (PGP4) displays auxin efflux activit...

1. Abstract 2. Introduction 3. Materials and methods 3.1. Decapitation pruning 3.2. Exogenous application of CPT 3.3. External application of auxin 3.4. Isolation of compounds 3.5. Cytotoxicity assays 3.6. DNA TOP1 assays 3.7. Statistical analysis 4. Results 4.1. Abnormal morphogenesis and elevated CPT levels following decapitation 4.2. Abnormal morphogenesis following exogenous application of ...

An auxin maximum is positioned along the xylem axis of the Arabidopsis root tip. The pattern depends on mutual feedback between auxin and cytokinins mediated by the PIN class of auxin efflux transporters and AHP6, an inhibitor of cytokinin signalling. This interaction has been proposed to regulate the size and the position of the hormones' respective signalling domains and specify distinct boun...

Title of Dissertation: THE ROLE OF AUXIN ON THE EVOLUTION OF EMBRYO DEVELOPMENT AND AXIS FORMATION IN LAND PLANTS DorothyBelle Poli, Doctor of Philosophy, 2005 Dissertation directed by: Professor Todd J. Cooke, Cell Biology and Molecular Genetics This thesis examined the role of auxin in the evolution of land plants. Several approaches were used to study how auxin regulates the development in t...

The plant hormone auxin (indole-3-acetic acid, IAA) has a crucial role in plant development. Its spatiotemporal distribution is controlled by a combination of biosynthetic, metabolic and transport mechanisms. Four families of auxin transporters have been identified that mediate transport across the plasma or endoplasmic reticulum membrane. Here we report the discovery and the functional charact...

The phytohormone auxin is one of the main directors of plant growth and development. In higher plants, auxin is generated in apical plant parts and transported from cell-to-cell in a polar fashion. Auxin is present in all plant phyla, and the existence of polar auxin transport (PAT) is well established in land plants. Algae are a group of relatively simple, autotrophic, photosynthetic organisms...

Polar transport of the phytohormone auxin throughout plants shapes morphogenesis and is subject to stringent and specific control. Here, we identify basic cellular activities connected to translational control of gene expression as sufficient to specify auxin-mediated development. Mutants in subunits of Arabidopsis Elongator, a protein complex modulating translational efficiency via maturation ...

The plant hormone auxin regulates many processes throughout plant growth and development. Aboveground auxin biosynthesis is thought to occur exclusively in the shoot apex, where it then moves via polar auxin transport (PAT) down through developing vasculature in the stem. In contrast to the canonical view of the shoot apex as the sole site of auxin production, there is some evidence to suggest ...

Auxin is an essential hormone for plant growth and development. Auxin influx carriers AUX1/LAX transport auxin into the cell, while auxin efflux carriers PIN pump it out of the cell. It is well established that efflux carriers play an important role in the shoot vascular patterning, yet the contribution of influx carriers to the shoot vasculature remains unknown. Here, we combined theoretical a...

Changes in the pattern of protein synthesis and in the translatable mRNA population have been examined during auxin-induced root development from excised mung bean seedlings. Several proteins, predominantly of low molecular weight and high pI, as shown by two-dimensional polyacrylamide gel electrophoresis, are synthesized specifically by auxin-treated tissue. These auxin-induced proteins appear...