title: Potato Tuber Induction is Regulated by Interactions Between Components of a Tuberigen Complex.
abstract: Photoperiod-regulated flowering and potato tuber formation involve leaf-produced mobile signals, florigen and tuberigen, respectively. The major protein component of florigen has been identified as the FLOWERING LOCUS T (FT) protein. In rice, an FT-like protein, Heading date 3a (Hd3a), induces flowering by making the florigen activation complex (FAC) through interactions with 14-3-3 and OsFD1, a rice FD-like protein. In potato, StSP6A, an FT-like protein, was identified as a major component of tuberigen. However, the molecular mechanism of how StSP6A triggers tuber formation remains elusive. Here we analyzed the significance of the formation of a complex including StSP6A, 14-3-3 and FD-like proteins in tuberization. Yeast two-hybrid, bimolecular fluorescence complementation and in vitro pull-down assays showed that StSP6A and StFDL1, a potato FD-like protein, interact with St14-3-3s. StSP6A overexpression induced early tuberization in a 14-3-3-dependent manner, and suppression of StFDL1 delayed tuberization. These results strongly suggest that an FAC-like complex, the tuberigen activation complex (TAC), comprised of StSP6A, St14-3-3s and StFDL1, regulates potato tuber formation.
authors.affiliation: Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Takayama, Ikoma, Japan.
authors.forename: Chin-Jit
authors.initials: CJ
authors.lastname: Teo
authors.affiliation: Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Takayama, Ikoma, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Takayama, Ikoma, Japan.
authors.forename: Kanae
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Takayama, Ikoma, Japan.
authors.forename: Ko
authors.initials: K
authors.lastname: Shimamoto
authors.affiliation: Laboratory of Plant Molecular Genetics, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Takayama, Ikoma, Japan.|Laboratory of Plant Genetic Resources, Kihara Institute for Biological Research, Yokohama City University, Maioka, Totsuka, Yokohama, Japan.
authors.forename: Ken-Ichiro
authors.initials: KI
authors.lastname: Taoka
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D035281:Plant Tubers / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D011485:Protein Binding; D011198:Solanum tuberosum / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*
chemical_list: D048948:14-3-3 Proteins; D010940:Plant Proteins
keywords: 14-3-3; FD; FT; Florigen; Solanum tuberosum; Tuberization