• 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.

中文翻译：

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海藻糖6-磷酸对拟南芥芽分支的调控

• 海藻糖6-磷酸（Tre6P）是一种蔗糖信号代谢产物，已参与调控枝条的分支，但其确切作用尚不清楚。
• 我们表达了TREHALOSE-6-磷酸合成酶1（TPS1）的标记形式，以确定在拟南芥（拟南芥）中合成Tre6P的位置，并研究了腋生芽或维管组织中Tre6P水平的局部变化对野生芽分支的影响。类型和分支突变体背景。
• TPS1在腋芽和对接的脉管系统以及叶和茎的脉管系统中表达。异源Tre6P磷酸酶（TPP）在腋芽中表达以降低Tre6P在长天中强烈延迟了芽的生长，并在短时间内抑制了分支。TPP在脉管系统中的表达也延迟了侧芽的生长并减少了分支。在血管系统中增加的Tre6P增强了分支，并伴随着FLOWERING LOCUS T（FT）的高表达和蔗糖转运蛋白的上调。增加的血管Tre6P水平增强了branched1中的分支，但并未增强ft突变体背景。
• 这些结果提供了直接的遗传学证据，表明Tre6P在芽自身内部的腋芽生长调节中的局部作用，并且还将Tre6P与通过FT的芽分支的系统性调节联系起来。