Vascular expression of trehalose phosphate synthase1 (TPS1) induces flowering in Arabidopsis

Trehalose and Trehalose-6-phosphate (T6P) have been described as signaling molecules involved in plant growth, development, carbon partitioning, flowering and response to biotic and abiotic stress. In order to investigate the role of T6P in vascular tissue signaling, Arabidopsis, plants expressing the TPS1 gene under the control of the actin depolymerizing factor 3 promoter (At5g59880) were generated by Agroinfiltration. Flower development and silique production occurred earlier in overexpressing lines compared to wild type (WT) control plants, while accumulation of TPS1 transcripts in overexpressing plants was considerably higher in silique, rosette and cauline leaves than in WT plants. Flowering Locus T (FT, AT1g65480) transcript was detected in rosette and cauline leaves in tps1 overexpressing lines, which could cause the observed early flowering. Trehalose levels were higher in rosette and cauline leaves in TPS1 lines, although no differences were observed in photosynthesis rate. These results suggest that the ectopic expression in the vasculature of the TPS1 gene induced trehalose accumulation in the vasculature, inducing flowering without compromising plant development.