title: Florigen distribution determined by a source-sink balance explains the diversity of inflorescence structures in Arabidopsis.
abstract: The ability to continue flowering after loss of inductive environmental cues that trigger flowering is termed floral commitment. Reversible transition involving a switch from floral development back to vegetative development has been found in Arabidopsis mutants and many plant species. Although the molecular basis for floral commitment remains unclear, recent studies suggest that the persistent activity of FLOWERING LOCUS T (FT) at inflorescences is required for floral commitment in Arabidopsis thaliana. Because FT encodes a mobile signal, florigen, which is generally transported from leaves to meristems through the phloem, understanding the transportation dynamics of FT is required to explore the role of FT on floral commitment. Here we developed a transportation model of leaf- and inflorescence-derived florigen and sucrose based on pressure-flow hypothesis. Depending on the demanded level of florigen supply for floral commitment of each floral meristem, the model predicted the change in inflorescence pattern from stable commitment to flower, transient flowering, and complete reversion. FT activity in inflorescence partly suppressed floral reversion, but complete suppression was achieved only when inflorescence became a source of sucrose. This finding highlights the importance of monitoring the spatio-temporal sucrose distribution and floral stimulus to understand inflorescence development mechanism.
authors: Departmnet of Biology, Faculty of Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan. Electronic address: akiko.satake@kyudai.jp.
authors: Akiko
authors: A
authors: Satake
authors: Departmnet of Informatics, Faculty of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors: Motohide
authors: M
authors: Seki
authors: Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8521, Japan.
authors: Makoto
authors: M
authors: Iima
authors: School of Medicine, Asahikawa Medical University, 2-1-1-1, Midorigaoka-higashi, Asahikawa 078-8510, Japan.
authors: Takashi
authors: T
authors: Teramoto
authors: WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors: Yasumasa
authors: Y
authors: Nishiura
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001693:Biological Transport, Active / Q000502:physiology; D060405:Florigen / Q000378:metabolism*; D008954:Models, Biological; D052585:Phloem / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C418905:FT protein, Arabidopsis; D060405:Florigen
keywords: Floral reversion; Florigen-threshold hypothesis; Hagen–Poiseuille equation; Inflorescence reversion; Phloem transportation; Pressure-flow hypothesis