title: Quantifying morphological features of actin cytoskeletal filaments in plant cells based on mathematical morphology.
abstract: By quantifying the morphological properties of biological structures, we can better evaluate complex shapes and detect subtle morphological changes in organisms. In this paper, we propose a shape analysis method based on morphological image processing, and apply it to image analysis of actin cytoskeletal filaments in root hair cells of Arabidopsis thaliana. In plant cells, the actin cytoskeletal filaments have critical roles in various cellular processes such as vesicle trafficking and organelle motility. The dynamics of vesicles and organelles in plant cells depend on actin cytoskeletal filaments, regulating cell division and cell enlargement. To better understand the actin-dependent organelle motility, we attempted to quantify the organization of actin filaments in the root hair cells of the root hair defective 3 (rhd3) mutant. RHD3 is involved in actin organization, and its defect has been reported to affect the dynamics of various vesicles and organelles. We measured three shape features of the actin filaments in wild-type and mutant plants. One feature (thickness) was depicted on a grayscale; the others (describing the complexity of the filament network patterns in two-dimensional space) were depicted as binary features. The morphological phenotypes of the cytoskeletal filaments clearly differed between wild-type and mutant. Subtle variations of filament morphology among the mutants were detected and statistically quantified.
authors.affiliation: Department of Imaging Science, Center for Novel Science Initiatives, National Institutes of Natural Sciences, Okazaki 444-8787, Japan; Laboratory of Biological Diversity, Department of Evolutionary and Biodiversity, National Institute for Basic Biology, Okazaki 444-8585, Japan; Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan. Electronic address: kimori@orion.ac.jp.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Kimori
authors.affiliation: Laboratory of Biological Diversity, Department of Evolutionary and Biodiversity, National Institute for Basic Biology, Okazaki 444-8585, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Hikino
authors.affiliation: Department of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Nishimura
authors.affiliation: Laboratory of Biological Diversity, Department of Evolutionary and Biodiversity, National Institute for Basic Biology, Okazaki 444-8585, Japan; Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Mano
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D017360:Arabidopsis / Q000166:cytology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003198:Computer Simulation; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D008962:Models, Theoretical; D009154:Mutation; D010363:Pattern Recognition, Automated; D010641:Phenotype; D059828:Plant Cells / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000166:cytology
chemical_list: D029681:Arabidopsis Proteins; D019204:GTP-Binding Proteins; C464507:RHD3 protein, Arabidopsis