@article{FichtnerOlasFeiletal.2020,
  author    = {Fichtner, Franziska and Olas, Justyna Jadwiga and Feil, Regina and Watanabe, Mutsumi and Krause, Ursula and Hoefgen, Rainer and Stitt, Mark and Lunn, John Edward},
  title     = {Functional features of Trehalose-6-Phosphate Synthase 1},
  series = {The Plant Cell},
  volume    = {32},
  journal   = {The Plant Cell},
  number    = {6},
  publisher = {Oxford University Press},
  address   = {Oxford},
  issn      = {0032-0781},
  doi       = {10.1105/tpc.19.00837},
  pages     = {1949 -- 1972},
  year      = {2020},
  abstract  = {Tre6P synthesis by TPS1 is essential for embryogenesis and postembryonic growth in Arabidopsis, and appropriate Suc signaling by Tre6P is dependent on the noncatalytic domains of TPS1. In Arabidopsis (Arabidopsis thaliana), TREHALOSE-6-PHOSPHATE SYNTHASE1 (TPS1) catalyzes the synthesis of the sucrose-signaling metabolite trehalose 6-phosphate (Tre6P) and is essential for embryogenesis and normal postembryonic growth and development. To understand its molecular functions, we transformed the embryo-lethal tps1-1 null mutant with various forms of TPS1 and with a heterologous TPS (OtsA) from Escherichia coli, under the control of the TPS1 promoter, and tested for complementation. TPS1 protein localized predominantly in the phloem-loading zone and guard cells in leaves, root vasculature, and shoot apical meristem, implicating it in both local and systemic signaling of Suc status. The protein is targeted mainly to the nucleus. Restoring Tre6P synthesis was both necessary and sufficient to rescue the tps1-1 mutant through embryogenesis. However, postembryonic growth and the sucrose-Tre6P relationship were disrupted in some complementation lines. A point mutation (A119W) in the catalytic domain or truncating the C-terminal domain of TPS1 severely compromised growth. Despite having high Tre6P levels, these plants never flowered, possibly because Tre6P signaling was disrupted by two unidentified disaccharide-monophosphates that appeared in these plants. The noncatalytic domains of TPS1 ensure its targeting to the correct subcellular compartment and its catalytic fidelity and are required for appropriate signaling of Suc status by Tre6P.},
  language  = {en}
}
@misc{FichtnerOlasFeiletal.2020,
  author    = {Fichtner, Franziska and Olas, Justyna Jadwiga and Feil, Regina and Watanabe, Mutsumi and Krause, Ursula and Hoefgen, Rainer and Stitt, Mark and Lunn, John Edward},
  title     = {Functional features of Trehalose-6-Phosphate Synthase 1},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {6},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51653},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-516532},
  pages     = {26},
  year      = {2020},
  abstract  = {Tre6P synthesis by TPS1 is essential for embryogenesis and postembryonic growth in Arabidopsis, and appropriate Suc signaling by Tre6P is dependent on the noncatalytic domains of TPS1. In Arabidopsis (Arabidopsis thaliana), TREHALOSE-6-PHOSPHATE SYNTHASE1 (TPS1) catalyzes the synthesis of the sucrose-signaling metabolite trehalose 6-phosphate (Tre6P) and is essential for embryogenesis and normal postembryonic growth and development. To understand its molecular functions, we transformed the embryo-lethal tps1-1 null mutant with various forms of TPS1 and with a heterologous TPS (OtsA) from Escherichia coli, under the control of the TPS1 promoter, and tested for complementation. TPS1 protein localized predominantly in the phloem-loading zone and guard cells in leaves, root vasculature, and shoot apical meristem, implicating it in both local and systemic signaling of Suc status. The protein is targeted mainly to the nucleus. Restoring Tre6P synthesis was both necessary and sufficient to rescue the tps1-1 mutant through embryogenesis. However, postembryonic growth and the sucrose-Tre6P relationship were disrupted in some complementation lines. A point mutation (A119W) in the catalytic domain or truncating the C-terminal domain of TPS1 severely compromised growth. Despite having high Tre6P levels, these plants never flowered, possibly because Tre6P signaling was disrupted by two unidentified disaccharide-monophosphates that appeared in these plants. The noncatalytic domains of TPS1 ensure its targeting to the correct subcellular compartment and its catalytic fidelity and are required for appropriate signaling of Suc status by Tre6P.},
  language  = {en}
}
@article{FichtnerBarbierAnnunziataetal.2020,
  author    = {Fichtner, Franziska and Barbier, Francois F. and Annunziata, Maria Grazia and Feil, Regina and Olas, Justyna Jadwiga and M{\"u}ller-R{\"o}ber, Bernd and Stitt, Mark and Beveridge, Christine A. and Lunn, John Edward},
  title     = {Regulation of shoot branching in arabidopsis by trehalose 6-phosphate},
  series = {New phytologist : international journal of plant science},
  volume    = {229},
  journal   = {New phytologist : international journal of plant science},
  number    = {4},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0028-646X},
  doi       = {10.1111/nph.17006},
  pages     = {2135 -- 2151},
  year      = {2020},
  abstract  = {Trehalose 6-phosphate (Tre6P) is a sucrose signalling metabolite that has been implicated in regulation of shoot branching, but its precise role is not understood. We expressed tagged forms of TREHALOSE-6-PHOSPHATE SYNTHASE1 (TPS1) to determine where Tre6P is synthesized in arabidopsis (Arabidopsis thaliana), and investigated the impact of localized changes in Tre6P levels, in axillary buds or vascular tissues, on shoot branching in wild-type and branching mutant backgrounds. TPS1 is expressed in axillary buds and the subtending vasculature, as well as in the leaf and stem vasculature. Expression of a heterologous Tre6P phosphatase (TPP) to lower Tre6P in axillary buds strongly delayed bud outgrowth in long days and inhibited branching in short days. TPP expression in the vasculature also delayed lateral bud outgrowth and decreased branching. Increased Tre6P in the vasculature enhanced branching and was accompanied by higher expression of FLOWERING LOCUS T (FT) and upregulation of sucrose transporters. Increased vascular Tre6P levels enhanced branching in branched1 but not in ft mutant backgrounds. These results provide direct genetic evidence of a local role for Tre6P in regulation of axillary bud outgrowth within the buds themselves, and also connect Tre6P with systemic regulation of shoot branching via FT.},
  language  = {en}
}
@misc{FichtnerBarbierAnnunziataetal.2020,
  author    = {Fichtner, Franziska and Barbier, Francois F. and Annunziata, Maria Grazia and Feil, Regina and Olas, Justyna Jadwiga and M{\"u}ller-R{\"o}ber, Bernd and Stitt, Mark and Beveridge, Christine A. and Lunn, John Edward},
  title     = {Regulation of shoot branching in arabidopsis by trehalose 6-phosphate},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {4},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-56956},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-569564},
  pages     = {19},
  year      = {2020},
  abstract  = {Trehalose 6-phosphate (Tre6P) is a sucrose signalling metabolite that has been implicated in regulation of shoot branching, but its precise role is not understood. We expressed tagged forms of TREHALOSE-6-PHOSPHATE SYNTHASE1 (TPS1) to determine where Tre6P is synthesized in arabidopsis (Arabidopsis thaliana), and investigated the impact of localized changes in Tre6P levels, in axillary buds or vascular tissues, on shoot branching in wild-type and branching mutant backgrounds. TPS1 is expressed in axillary buds and the subtending vasculature, as well as in the leaf and stem vasculature. Expression of a heterologous Tre6P phosphatase (TPP) to lower Tre6P in axillary buds strongly delayed bud outgrowth in long days and inhibited branching in short days. TPP expression in the vasculature also delayed lateral bud outgrowth and decreased branching. Increased Tre6P in the vasculature enhanced branching and was accompanied by higher expression of FLOWERING LOCUS T (FT) and upregulation of sucrose transporters. Increased vascular Tre6P levels enhanced branching in branched1 but not in ft mutant backgrounds. These results provide direct genetic evidence of a local role for Tre6P in regulation of axillary bud outgrowth within the buds themselves, and also connect Tre6P with systemic regulation of shoot branching via FT.},
  language  = {en}
}