title: AtTCTP2, an Arabidopsis thaliana homolog of Translationally Controlled Tumor Protein, enhances in vitro plant regeneration.
abstract: The Translationally Controlled Tumor Protein (TCTP) is a central regulator of cell proliferation and differentiation in animals, and probably also in plants. Arabidopsis harbors two TCTP genes, AtTCTP1 (At3g16640), which is an important mitotic regulator, and AtTCTP2 (At3g05540), which is considered a pseudogene. Nevertheless, we have obtained evidence suggesting that this gene is functional. Indeed, a T-DNA insertion mutant, SALK_045146, displays a lethal phenotype during early rosette stage. Also, both the AtTCTP2 promoter and structural gene are functional, and heterozygous plants show delayed development. AtTCTP1 cannot compensate for the loss of AtTCTP2, since the accumulation levels of the AtTCTP1 transcript are even higher in heterozygous plants than in wild-type plants. Leaf explants transformed with Agrobacterium rhizogenes harboring AtTCTP2, but not AtTCTP1, led to whole plant regeneration with a high frequency. Insertion of a sequence present in AtTCTP1 but absent in AtTCTP2 demonstrates that it suppresses the capacity for plant regeneration; also, this phenomenon is enhanced by the presence of TCTP (AtTCTP1 or 2) in the nuclei of root cells. This confirms that AtTCTP2 is not a pseudogene and suggests the involvement of certain TCTP isoforms in vegetative reproduction in some plant species.
authors.affiliation: Laboratory of Plant Molecular Biology, Department of Biotechnology and Bioengineering, CINVESTAV Mexico City, Mexico.
authors.forename: Roberto
authors.initials: R
authors.lastname: Toscano-Morales
authors.affiliation: Laboratory of Plant Molecular Biology, Department of Biotechnology and Bioengineering, CINVESTAV Mexico City, Mexico.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Xoconostle-Cázares
authors.affiliation: Department of Plant Genetic Enginneering, CINVESTAV Unidad Irapuato Irapuato, Mexico.
authors.forename: José L
authors.initials: JL
authors.lastname: Cabrera-Ponce
authors.affiliation: Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla, Ciudad Universitaria Puebla, Mexico.
authors.forename: Jesús
authors.initials: J
authors.lastname: Hinojosa-Moya
authors.affiliation: Laboratory of Plant Molecular Biology, Department of Biotechnology and Bioengineering, CINVESTAV Mexico City, Mexico.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Ruiz-Salas
authors.affiliation: Laboratory of Plant Molecular Biology, Department of Biotechnology and Bioengineering, CINVESTAV Mexico City, Mexico.
authors.forename: Santiago V
authors.initials: SV
authors.lastname: Galván-Gordillo
authors.affiliation: CA Ingenieria de Biosistemas, Centro Universitario Cerro de las Campanas, Universidad Autónoma de Querétaro Santiago de Querétaro, Mexico.
authors.forename: Ramón G
authors.initials: RG
authors.lastname: Guevara-González
authors.affiliation: Laboratory of Plant Molecular Biology, Department of Biotechnology and Bioengineering, CINVESTAV Mexico City, Mexico.
authors.forename: Roberto
authors.initials: R
authors.lastname: Ruiz-Medrano
keywords: Agrobacterium rhizogenes; TCTP; lateral root; plant regeneration; vascular expression