Agrobacterium tumefaciens can genetically transform various eukaryotic cells because of the presence of a resident tumor-inducing (Ti) plasmid. During infection, a defined region of the Ti plasmid, transfer DNA (T-DNA), is transferred from bacteria into plant cells and causes plant cells to abnormally synthesize auxin and cytokinin, which results in crown gall disease. T-DNA and several virulen...

Tyrosine sulfation is a posttranslational modification common in peptides and proteins synthesized by the secretory pathway in most eukaryotes. In plants, this modification is critical for the biological activities of a subset of peptide hormones such as PSK and PSY1. In animals, tyrosine sulfation is catalyzed by Golgi-localized type II transmembrane proteins called tyrosylprotein sulfotransfe...

Lead is a heavy metal of particular concern with respect to environmental quality and health. The lack of plant species that accumulate and tolerate Pb is a limiting factor to understand the molecular mechanisms involved in Pb tolerance. In this study we identified Hirschfeldia incana, a Brassicaceae collected from metalliferous mine spoils in Morocco, as a Pb accumulator plant. H. incana exhib...

Adenosine kinase (ADK, EC 2.7.1.20) is a purine salvage enzyme, which phosphorylates adenosine (Ado) to AMP. It may also contribute to the interconversion of cytokinin ribosides and nucleotides. Recent microarray analyses have provided new insights into the impact of ADK activity towards plant metabolism and development. The majority of these findings reflect ADK's role in the metabolism of Ado...

The 3-ketoacyl-ACP synthase (KAS) II is a fatty-acid-related enzyme which catalyzes the elongation of 16:0-acyl carrier protein (ACP) to 18:0-ACP in plastids. The fatty acid biosynthesis 1-1 (fab1-1) mutant of Arabidopsis thaliana is partially deficient in its activity of Arabidopsis thaliana 3-ketoacyl-ACP synthase 2 (AtKAS2), and its phenotype has been intensively studied in connection with t...

Polar auxin transport plays a key role in the regulation of plant growth and development. To identify genes involved in this process, we have developed a genetic procedure to screen for mutants of Arabidopsis that are altered in their response to auxin transport inhibitors. We recovered a total of 16 independent mutants that defined seven genes, called TRANSPORT INHIBITOR RESPONSE (TIR) genes. ...

BACKGROUND The conserved SNF1/AMPK/SnRK1 complexes are global regulators of metabolic responses in eukaryotes and play a key role in the control of energy balance. Although α-type subunits of the SnRK1 complex have been characterized in several plant species, the biological function of β-type and γ-type subunits remains largely unknown. Here, we characterized AtPV42a and AtPV42b, the two homolo...

The role of the eukaryotic release factor 1 (eRF1) in translation termination has previously been established in yeast; however, only limited characterization has been performed on any plant homologs. Here, we demonstrate that cosuppression of eRF1-1 in Arabidopsis (Arabidopsis thaliana) has a profound effect on plant morphology, resulting in what we term the broomhead phenotype. These plants p...

Nuclear magnetic resonance (NMR) microscopy is a completely noninvasive technique that can be used to acquire images with high spatial resolution through opaque objects such as plant organs and tissue parts. The image contrast can be chosen to represent the anatomical details or to visualize the spatial distribution of a range of physico-chemical parameters such as the apparent diffusion consta...