Figure 1. Mechanistic basis for the impact of T6P on growth, architecture and metabolism and demonstrated links to crops traits.

T6P as a signal of sucrose inhibits SnRK1 to promote biosynthetic pathways [9] through change in SnRK1 phosphorylation [15]. SnRK1 regulates trehalose phosphate synthases (TPS) through transcription control [11] and phosphorylation [49] and transcription of TPPs through b-ZIP transcription factor [41]. Dotted lines in the figure denote transcription. There is evidence that SnRK1 regulates b-ZIPs [10]. SWEET transporters may be important downstream targets for the regulation of sucrose allocation [19]. Wide ranging traits in four food security cereals are associated with T6P as seen through transgenic modification in maize and rice [13,24], natural genetic variation in wheat [43,45], rice [26] and sorghum [40] and chemical intervention with T6P precursors in wheat [42].