Fig. 1.

A summary of the trehalose biosynthetic pathway and its role in regulating resource allocation. TPSs (trehalose phosphate synthases) and TPPs (trehalose phosphate phosphatases) regulate the synthesis of trehalose 6-phosphate, a key metabolic signal and regulator of SnRK1 (SNF1-related kinase 1). SnRK1 regulates TPS by phosphorylation and activates TPP transcription through the C/S1 group bZIPs (Harthill et al., 2006; Ma et al., 2011). SnRK1 regulates biosynthetic pathways through regulation of gene expression (starch, oil, and cell wall) (Zhang et al., 2009; Figueroa and Lunn, 2016; Zhai et al., 2018) and sucrose allocation through regulation of SWEET transporter transcription (Oszvald et al., 2018).