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Regulation of shoot branching in arabidopsis by trehalose 6‐phosphate
Author(s) -
Fichtner Franziska,
Barbier Francois F.,
Annunziata Maria G.,
Feil Regina,
Olas Justyna J.,
MuellerRoeber Bernd,
Stitt Mark,
Beveridge Christine A.,
Lunn John E.
Publication year - 2021
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.17006
Subject(s) - axillary bud , trehalose , arabidopsis , biology , shoot , mutant , microbiology and biotechnology , branching (polymer chemistry) , vascular tissue , sucrose , botany , biochemistry , chemistry , gene , in vitro , tissue culture , organic chemistry
Summary 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.