SnRK1 deficiency restores flowering and embryogenesis in the Arabidopsis trehalose 6-phosphate synthase1 (tps1) mutant

Flowering time control is crucial for plant survival and is directly linked to seed maturation and harvesting time. It involves a wide range of both environmental and endogenous stimuli. Flowering is a highly energy demanding process and it is therefore important for plants to sense when sufficient resources are available in order to successfully complete their life cycle. TREHALOSE 6-PHOSPHATE SYNTHASE 1 (TPS1) and its product, trehalose 6-phosphate (T6P), play an important regulatory role in the metabolic control of plant development. In Arabidopsis thaliana, loss of function of TPS1 results in attenuated embryogenesis and vegetative development and strongly delays flowering by modulating the activity of the photoperiod pathway in leaves and the age pathway in the shoot apical meristem (SAM). T6P was suggested to regulate development in part through inhibition of SUCROSE NON-FERMENTING RELATED KINASE1 (SnRK1). Here we show that newly identified loss-of-function mutations in the SnRK1 complex subunits can restore both embryogenesis and flowering in the tps1-2 mutant. Flowering is restored via the miR156/SQUAMOSA PROMOTER BINDING-LIKE (SPL) node in the SAM and largely independent of FLOWERING LOCUS T (FT).