title: Cytological and biochemical analysis of COF1, an Arabidopsis mutant of an ABC transporter gene.
abstract: In transposon-tagged lines of Arabidopsis we found two new mutants, cof1-1 and cof1-2 (cuticular defect and organ fusion), that show the phenotype of wilting when grown in soil, organ fusion of rosette leaves and infertility. Toluidine blue testing and scanning electron microscopy observation revealed that these mutants had cuticular defects in the stems and adult leaves, but not in cotyledones. Transmission electron microscopy observation revealed thinner cuticle layers in the mutants, and cuticular materials interspersed between the two fused epidermal layers were observed in the mutant rosette leaves. These two mutants had a transposon insertion in the coding regions of WBC11, which was classified as a member of ABC transporter genes in Arabidopsis. WBC11 showed high sequence similarity to CER5 (also called WBC12), which was involved in cuticular lipid export. Gas chromatographic analysis revealed that C29 alkane extracted from the stem surface of cof1 mutants was reduced whereas C29 ketone was accumulated, which was different from the case of cer5 mutants. While cer5 mutants had fairly normal morphology, cof1 mutants had pleiotropic phenotypes so that COF1/WBC11 could have important roles different from those of CER5/WBC12. We also found that C29 alkane was accumulated in the intracellular extract of cof1 mutants, suggesting a function for WBC11 in the direct transport of lipid molecules. Pollen observation showed that mutant pollen grains were irregularly shaped. The function of COF1/WBC11 in lipid transport for the construction of cuticle layers and pollen coats for normal organ formation is discussed.
authors.affiliation: International Graduate School of Arts and Science, Yokohama City University, Yokohama, Kanagawa, 230-0045 Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ukitsu
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuromori
authors.forename: Kiminori
authors.initials: K
authors.lastname: Toyooka
authors.forename: Yumi
authors.initials: Y
authors.lastname: Goto
authors.forename: Ken
authors.initials: K
authors.lastname: Matsuoka
authors.forename: Eiji
authors.initials: E
authors.lastname: Sakuradani
authors.forename: Sakayu
authors.initials: S
authors.lastname: Shimizu
authors.forename: Asako
authors.initials: A
authors.lastname: Kamiya
authors.forename: Yuko
authors.initials: Y
authors.lastname: Imura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yuguchi
authors.forename: Takuji
authors.initials: T
authors.lastname: Wada
authors.forename: Takashi
authors.initials: T
authors.lastname: Hirayama
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shinozaki
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D002849:Chromatography, Gas; D018506:Gene Expression Regulation, Plant; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009154:Mutation; D010802:Phylogeny; D019441:Plant Epidermis / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D011058:Pollen / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D018528:ATP-Binding Cassette Transporters; D029681:Arabidopsis Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins