Blooming’s Sweet Spot

Flowering is the salient goal of all higher plants, and this important process is controlled by dozens of genes and a handful of hormones. Plant scientists in Germany have now figured out how one molecule, a sugar called trehalose-6-phosphate (T6P), is essential in triggering the onset of blooming (Science, DOI: 10.1126/science.1230406). “There’s not one definitive switch in plant flowering,” explains Markus Schmid of the Max Plank Institute for Developmental Biology, who led the research. The redundancy ensures that flowering will commence even under less than ideal environmental conditions, Schmid notes. That said, T6P is among the most important flowering cues, he adds. Schmid and his team found that high levels of T6P indicate that a plant has enough energy reserves to commence the metabolically expensive task of flowering. The researchers also observed that in Arabidopsis thaliana, a small flowering plant commonly used in plant biology studies, T6P activates production of a key protein. The protein then travels from the leaves to the growing tip of the plant—called the meristem—to stimulate flowering.