The Ypt3/Rab11/Rab25 subfamily of Rab GTPases has expanded greatly in Arabidopsis thaliana, comprising 26 members in six provisional subclasses, Rab-A1 to Rab-A6. We show that the Rab-A2 and Rab-A3 subclasses define a novel post-Golgi membrane domain in Arabidopsis root tips. The Rab-A2/A3 compartment was distinct from but often close to Golgi stacks and… (More)
Cytokinesis represents the final stage of eukaryotic cell division during which the cytoplasm becomes partitioned between daughter cells. The process differs to some extent between animal and plant cells, but proteins of the syntaxin family mediate membrane fusion in the plane of cell division in diverse organisms. How syntaxin localization is kept in check… (More)
Plant stems and roots orient themselves with respect to directional illumination and gravity by differential growth on either side of the organ. A model formulated in the 1930s proposed that tropic growth curvature arose from growth hormone redistribution. Studies with Arabidopsis are beginning to reveal the mechanism.
BACKGROUND The number of medical studies performed through online surveys has increased dramatically in recent years. Despite their numerous advantages (eg, sample size, facilitated access to individuals presenting stigmatizing issues), selection bias may exist in online surveys. However, evidence on the representativeness of self-selected samples in online… (More)
Assessment of gene function generally requires knowledge of the sites of action of gene products. Several experimental approaches can provide relevant information, but all have their limitations and the potential for experimental artifact. In this article we focus on the endomembrane organelles and on the methods that can be used to validate the location of… (More)
Endocytosis occurs in plants, but the involvement of clathrin-coated vesicles has been unclear; a new study provides strong evidence that, as in animal cells, clathrin-coated vesicles are a major means of internalisation by plant cells.
Dividing plant cells assemble a new intracellular compartment, the cell plate, which grows centrifugally by vesicle fusion to partition the cytoplasm. Genetic studies in Arabidopsis are revealing the molecular signals that specify this special membrane transport pathway.
Plant organogenesis requires control over division planes and anisotropic cell wall growth, which each require spatial patterning of cells. Polyhedral plant cells can display complex patterning in which individual faces are established as biochemically distinct domains by endomembrane trafficking. We now show that, during organogenesis, the Arabidopsis… (More)
A subset of genes in Arabidopsis thaliana is known to be up-regulated in response to a wide range of different environmental stress factors. However, not all of these genes are characterized as yet with respect to their functions. In this study, we used transgenic knockout, overexpression and reporter gene approaches to try to elucidate the biological roles… (More)