A5082921340- Plant Reproductive Biology
- Plant Molecular Biology Research
- Marine and coastal plant biology
- Polysaccharides and Plant Cell Walls
- Algal biology and biofuel production
- Plant nutrient uptake and metabolism
- Biocrusts and Microbial Ecology
- Photosynthetic Processes and Mechanisms
- Plant tissue culture and regeneration
- Marine Biology and Environmental Chemistry
- Microtubule and mitosis dynamics
- Cellular transport and secretion
- Coastal wetland ecosystem dynamics
- Plant Taxonomy and Phylogenetics
- Fern and Epiphyte Biology
- Plant-Microbe Interactions and Immunity
- Plant Growth Enhancement Techniques
- Plant and Biological Electrophysiology Studies
- Freezing and Crystallization Processes
- Tree Root and Stability Studies
- Neuroscience and Neuropharmacology Research
- Neurobiology and Insect Physiology Research
- Seed Germination and Physiology
- Plant responses to water stress
- Legume Nitrogen Fixing Symbiosis
St. Francis Xavier University
2003-2020
Australian National University
1986-2003
University of Michigan–Ann Arbor
1993-1997
Stanford University
1994
University of Saskatchewan
1993
Carleton University
1987
Memorial University of Newfoundland
1983
ABSTRACT The role of the Arabidopsis homeobox gene, GLABRA 2 (GL2), in development root epidermis has been investigated. wild-type is composed two cell types, root-hair cells and hairless cells, which are located at distinct positions within root, implying that positional cues control cell-type differentiation. During epidermis, differentiating (trichoblasts) (atrichoblasts) can be distinguished by their cytoplasmic density, vacuole formation, extent elongation. We have determined mutations...
Multiple cellulose synthase (CesA) subunits assemble into plasma membrane complexes responsible for production. In the Arabidopsis (Arabidopsis thaliana) model system, we identified a novel D604N missense mutation, designated anisotropy1 (any1), in essential primary cell wall CesA1. Most previously CesA1 mutants show severe constitutive or conditional phenotypes such as embryo lethality arrest of production but any1 plants are viable and produce seeds, thus permitting study function. The...
The expansion of both root hairs and pollen tubes occurs by a process known as tip growth. In this report, an Arabidopsis thaliana mutant (tip1) is described that displays defects in root-hair pollen-tube the tip1 plants are shorter than those wild-type branched at their base. growth defect was identified aberrant segregation ratio phenotypically normal to seeds siliques from self-pollinated, heterozygous plants. Homozygous not randomly distributed siliques, comprising only 14.4% total...
Summary Exocytosis and endocytosis are pivotal in many biological processes, but remain difficult to quantify. Here we combine a new algorithm for estimating vesicle size with detailed morphological analysis of tip‐growing cells, which exocytosis is highly localized therefore more readily quantified. Cell preservation was rendered as life‐like possible by rapid freezing. This allowed us produce the first estimates rates root hairs pollen tubes model plant Arabidopsis. To quantify during cell...
ABSTRACT An ultrastructural study of endocytosis has been made for the first time in protoplasts a gymnosperm, white spruce (Picea glauca), fixed by high-pressure freezing and freeze substitution. Protoplasts derived from WS1 line suspension-cultured embryogenic were labelled with cationized ferritin, non-specific marker plasma membrane. The timing ferritin uptake its subcellular distribu-tion determined fixing at various intervals after labelling. To address concerns about using chemical...
Rapid progress is being made in determining the composition, synthesis, and mechanical properties of plant cell walls. Although tip-growing root hairs provide an excellent example high-speed wall assembly, they have been relatively neglected by researchers interested walls those tip growth. This review aims to present hair as experimental system for future studies assembling recent discoveries about onto existing framework based on older information. Most data come from arabidopsis (...
:Epidermal shedding, a process that effectively controls epiphyte accumulation on certain long-lived macroalgae, was quantified weekly for over 1 year in population of Ascophyllum nodosum from Nova Scotia. About 25% the frond epidermis is shed per week and at least 9 months year, this shedding occurred population-level cycles skin followed by reaccumulation epiphytes. Using geometric model based cross-sectional area branches assigned to one four size categories, we determined about 1%...
Indirect immunofluorescence microscopy was used to survey the three‐dimensional distribution of microtubules throughout cell cycle in green alga Mougeotia. The network present cortex cells at interphase gradually disappeared before mitosis. A band cortical reminiscent preprophase higher plants surrounded nuclei some undergoing microtubule disassembly. Longitudinally oriented bundles appeared future spindle poles on either side prophase. These as arrays formed. New spindles had broad but...
A recessive mutation in the RHD4 gene of Arabidopsis thaliana L. affects control tip growth seedling root hairs. Fully grown rhd4 hairs are half length wild-type (WT) The wider, and they vary diameter during growth. Light microscopy motion analysis revealed that grow more slowly hair rate varies than WT Hair increases at tips when slows. Ultrastructural cell wall thickenings some mutant were a hyperosmotic medium an attempt to mimic investigate morphology. Osmotic stress increased induced...
Fluorescence and electron microscopy were used to examine epidermal shedding in the fucoid alga, Ascophyllum nodosum.Mature meristoderm cells are ca.50-100 x 30-40 µm highly polarized, with a single nucleus chloroplasts near base of cell.Nuclei these undergo mitosis when they dividing form new cortical cell towards middle frond, or anticlinal divisions as part frond elongation.However, cytokinesis also occurs regularly periclinal wall is deposited at about 30% length from apical end.The...
:Halat et al. (2015 Halat L., Galway M.E., Gitto S. & Garbary D.J. 2015. Epidermal shedding in Ascophyllum nodosum (Phaeophyceae): seasonality, productivity and relationship to harvesting. Phycologia 54: 599–608.[Taylor Francis Online], [Web of Science ®] , [Google Scholar]. 599–608) concluded that the commercial harvest Nova Scotia resulted a detrital deficit amounting over 100% biomass. Here we respond Ugarte (2017. 57: 114–115) our estimate was exaggerated. We reaffirm conclusions that:...