TY  - JOUR
A1  - Fichtner, Franziska
A1  - Barbier, Francois F.
A1  - Annunziata, Maria Grazia
A1  - Feil, Regina
A1  - Olas, Justyna Jadwiga
A1  - Müller-Röber, Bernd
A1  - Stitt, Mark
A1  - Beveridge, Christine A.
A1  - Lunn, John Edward
T1  - Regulation of shoot branching in arabidopsis by trehalose 6-phosphate
JF  - New phytologist : international journal of plant science
N2  - 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.
KW  - Arabidopsis thaliana (arabidopsis)
KW  - axillary bud
KW  - branching
KW  - sucrose
KW  - sugar signalling
KW  - trehalose 6‐ phosphate (Tre6P)
Y1  - 2020
U6  - https://doi.org/10.1111/nph.17006
SN  - 0028-646X
SN  - 1469-8137
VL  - 229
IS  - 4
SP  - 2135
EP  - 2151
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Annunziata, Maria Grazia
A1  - Apelt, Federico
A1  - Carillo, Petronia
A1  - Krause, Ursula
A1  - Feil, Regina
A1  - Mengin, Virginie
A1  - Lauxmann, Martin A.
A1  - Koehl, Karin
A1  - Nikoloski, Zoran
A1  - Stitt, Mark
A1  - Lunn, John Edward
T1  - Getting back to nature: a reality check for experiments in controlled environments
JF  - Journal of experimental botany
N2  - Irradiance from sunlight changes in a sinusoidal manner during the day, with irregular fluctuations due to clouds, and light-dark shifts at dawn and dusk are gradual. Experiments in controlled environments typically expose plants to constant irradiance during the day and abrupt light-dark transitions. To compare the effects on metabolism of sunlight versus artificial light regimes, Arabidopsis thaliana plants were grown in a naturally illuminated greenhouse around the vernal equinox, and in controlled environment chambers with a 12-h photoperiod and either constant or sinusoidal light profiles, using either white fluorescent tubes or light-emitting diodes (LEDs) tuned to a sunlight-like spectrum as the light source. Rosettes were sampled throughout a 24-h diurnal cycle for metabolite analysis. The diurnal metabolite profiles revealed that carbon and nitrogen metabolism differed significantly between sunlight and artificial light conditions. The variability of sunlight within and between days could be a factor underlying these differences. Pairwise comparisons of the artificial light sources (fluorescent versus LED) or the light profiles (constant versus sinusoidal) showed much smaller differences. The data indicate that energy-efficient LED lighting is an acceptable alternative to fluorescent lights, but results obtained from plants grown with either type of artificial lighting might not be representative of natural conditions.
KW  - Amino acid
KW  - Arabidopsis thaliana
KW  - controlled environment
KW  - LED lighting
KW  - visible light spectrum
KW  - organic acid
KW  - starch
KW  - sucrose
KW  - trehalose 6-phosphate
Y1  - 2017
U6  - https://doi.org/10.1093/jxb/erx220
SN  - 0022-0957
SN  - 1460-2431
VL  - 68
SP  - 4463
EP  - 4477
PB  - Oxford Univ. Press
CY  - Oxford
ER  -