title: Mutation in the Arabidopisis thaliana DEK1 calpain gene perturbs endosperm and embryo development while over-expression affects organ development globally.
abstract: A T-DNA insertion in the Arabidopsis thaliana DEK1 gene, encoding a calpain-like cysteine proteinase with a predicted membrane anchor, causes unorganized embryo development displaying irregular mitotic divisions in the embryo proper and suspensor. Embryo development is arrested at the globular stage, and the embryo proper lacks a defined protoderm. In the endosperm, the aleurone-like peripheral cell layer is partly or completely lacking. The Arabidopsis DEK1 wild-type transcript is expressed evenly throughout the endosperm and the embryo in developing seed as determined using in situ hybridization. The conclusion that the observed phenotype is caused by a T-DNA insertion in the Arabidopsis DEK1 gene is confirmed by complementation with the Arabidopisis DEK1 genomic sequence, as well as analysis of a second T-DNA insertion allele. Over-expression of the Arabidopsis DEK1 gene coding sequence under the control of the 35S promoter causes a number of developmental phenotypes, including a global lack of trichomes, leaves exhibiting improper dorsiventral symmetry and aberrant cell organization in flowers. We interpret the data to suggest a role for DEK1 in providing cells with positional clues for an appropriate developmental context within plant tissues.
authors.affiliation: Department of Plant and Environmental Sciences, Agricultural University of Norway, P.O. Box 5003, 1432 As, Norway.
authors.forename: Stein Erik
authors.initials: SE
authors.lastname: Lid
authors.forename: Lene
authors.initials: L
authors.lastname: Olsen
authors.forename: Ragnhild
authors.initials: R
authors.lastname: Nestestog
authors.forename: Milo
authors.initials: M
authors.lastname: Aukerman
authors.forename: Roy C
authors.initials: RC
authors.lastname: Brown
authors.forename: Betty
authors.initials: B
authors.lastname: Lemmon
authors.forename: Mark
authors.initials: M
authors.lastname: Mucha
authors.forename: Hilde-Gunn
authors.initials: HG
authors.lastname: Opsahl-Sorteberg
authors.forename: Odd-Arne
authors.initials: OA
authors.lastname: Olsen
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics*; D002154:Calpain / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D012639:Seeds / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure
chemical_list: D029681:Arabidopsis Proteins; D002154:Calpain