title: Cloning of Pinus sylvestris SCARECROW gene and its expression pattern in the pine root system, mycorrhiza and NPA-treated short roots.
abstract: The SCARECROW (SCR) gene is central to root radial patterning. Its expression has not been investigated in conifers with morphologically different root types. Additional interest in SCR functions in the Pinus sylvestris root system comes from the effect of ectomycorrhiza formation on the short root apical structure. Here, the P. sylvestris SCR gene (PsySCR) was cloned and its expression investigated by northern blot and in situ hybridization of primary, lateral and short roots and mycorrhiza. Short root dichotomization was induced by auxin transport inhibitor (N-1-naphthylphthalamic acid (NPA)). PsySCR has conserved GRAS family protein motifs at the C-terminus and a variable N-terminus. PsySCR expression occurred in young root tissue and mycorrhiza. In root sections the PsySCR signal runs through the tip in initials for stele and root cap column and becomes upwards-restricted to endodermis in all root types. The PsySCR expression pattern suggests for the first time a regulatory role for SCR in maintaining the endodermal characteristics and radial patterning of roots with open meristem organization. The specific PsySCR localization is also an excellent marker for investigation of the dichotomization process in short roots.
authors.affiliation: Plant Biology, Department of Biological and Environmental Sciences, FI-00014 University of Helsinki, Finland.
authors.forename: Kaisa
authors.initials: K
authors.lastname: Laajanen
authors.affiliation: Plant Biology, Department of Biological and Environmental Sciences, FI-00014 University of Helsinki, Finland.
authors.forename: Irmeli
authors.initials: I
authors.lastname: Vuorinen
authors.affiliation: Plant Biology, Department of Biological and Environmental Sciences, FI-00014 University of Helsinki, Finland.|Botany, Department of Applied Biology, University of Helsinki, FI-00014 University of Helsinki, Finland.
authors.forename: Vanamo
authors.initials: V
authors.lastname: Salo
authors.affiliation: General Microbiology, Department of Biological and Environmental Sciences, FI-00014 University of Helsinki, Finland.
authors.forename: Jarmo
authors.initials: J
authors.lastname: Juuti
authors.affiliation: Plant Physiology and Molecular Biology, Department of Biology, FI-20014 University of Turku, Finland.
authors.forename: Marjatta
authors.initials: M
authors.lastname: Raudaskoski
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics*; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000378:metabolism*; D010797:Phthalimides / Q000494:pharmacology*; D010802:Phylogeny; D041605:Pinus sylvestris / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D010797:Phthalimides; C002687:alpha-naphthylphthalamic acid