Trehalose 6-phosphate.

Trehalose 6-phosphate (T6P) is a sugar signal of emerging significance. It is an essential component of the mechanisms that coordinate metabolism with plant growth adaptation and development. Its significance began to dawn when genetic modification of the trehalose pathway produced dramatic phenotypes, before the genetic proliferation of the trehalose pathway in plants was fully realised. T6P regulates sugar utilization and starch metabolism and interacts with other signalling pathways, including those mediated by plant hormones. Trehalose phosphate synthases (TPSs) and trehalose phosphate phosphatases are regulated at the gene level by sugars, nitrate, cytokinin and abscisic acid. TPSs are also regulated post-translationally. Mechanistic details of how T6P signals are emerging, but still sparse. Nevertheless, even at this stage, targeting central regulators such as T6P offers promise in crop improvement.