title: The Arabidopsis SPIKE1 gene is required for normal cell shape control and tissue development.
abstract: Regulated growth and cell shape control are fundamentally important to the function of plant cells, tissues, and organs. The signal transduction cascades that control localized growth and cell shape, however, are not known. To better understand the relationship between cytoskeletal organization, organelle positioning, and regulated vesicle transport, we conducted a forward genetic screen to identify genes that regulate cytoskeletal organization in plants. Because of the distinct requirements for microtubules and actin filaments during leaf trichome development, a trichome-based morphology screen is an efficient approach to identify genes that affect cytoplasmic organization. The seedling lethal spike1 mutant was identified based on trichome, cotyledon, and leaf-shape defects. The predicted SPIKE1 protein shares amino acid identity with a large family of adapter proteins present in humans, flies, and worms that integrate extracellular signals with cytoskeletal reorganization. Both the trichome phenotype and immunolocalization data suggest that SPIKE1 also is involved in cytoskeletal reorganization. The assembly of laterally clustered foci of microtubules and polarized growth are early events in cotyledon development, and both processes are misregulated in spike1 epidermal cells.
authors.affiliation: Department of Agronomy, Purdue University, 1150 Lilly Hall of Life Sciences, West Lafayette, Indiana 47907-1150, USA.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Qiu
authors.forename: Ross
authors.initials: R
authors.lastname: Jilk
authors.forename: M David
authors.initials: MD
authors.lastname: Marks
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Szymanski
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D048429:Cell Size / Q000235:genetics; D022081:Cell Surface Extensions / Q000235:genetics; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D018548:Cotyledon / Q000166:cytology / Q000254:growth & development*; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D019441:Plant Epidermis / Q000166:cytology / Q000254:growth & development*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; C455512:SPIKE1 protein, Arabidopsis