Tag: Cell Biology

Saffer et al. identified an Arabidpsis mutant with swirled petals and with petal epidermal cells that show a left-handed (but never right-handed) twist. They mapped the mutation to the RHAMNOSE BIOSYNTHESIS1 (RHM1) gene, which is most highly expressed in petal epidermal cells and encodes an enzyme that…

It’s easy to demonstrate that plants sense gravity, and we also know that statocytes are involved in the perception of gravity. Statocytes are gravity-sensing cells that contain dense starch-containing amyloplasts that move within the cell in the direction of gravity. Differential growth to accommodate…

Hu et al. found a sterile rice mutant defective in meiosis. They mapped it to MEICA1, a widely conserved but uncharacterized protein required to ensure crossovers occur between allelic regions of chromosomes. It also inhibits allelic homologous recombination. This adds to a suite of proteins eukaryotic…

Calcium signalling is a ubiquitous process in plants and other organisms. Transporters at the plasma and vacuolar (tonoplast) membranes control entry and exit of calcium ion into the cytoplasm, and it is the cytoplasmic calcium level ([Ca2+]cyt) that affects cellular responses, as calcium-binding proteins…

Following double fertilization, the embryo and the endosperm form within a developing seed. In Arabidopsis, the endosperm is somewhat transient, as most of the space it occupies is eventually taken over by the embryo. The question of how the embryo pushes aside the endosperm has not been fully clear.…

Bacterial effectors are proteins produced by bacteria and introduced into their hosts, where the effectors support successful infection by the pathogen. Effectors can function in diverse cells and cell compartments, but many studies of effector localization have relied on overexpression systems which…

Plasmodesmata are pores between cells through which viruses, proteins, small RNAs and other molecules can pass. The pores are usually described as being lined with a layer of plasma membrane with a tube of endoplasmic-reticulum membrane through the center. These membranes and associated proteins are…

The waxy cuticle, a key barrier to desiccation and pathogen entry, is a dynamic structure, the composition, area, permeability and thickness of which can change in response to environmental conditions.  For example, water deficit in Arabidopsis (Arabidopsis thaliana) triggers an increase in the accumulation…